Patent Publication Number: US-2023137108-A1

Title: Semiconductor interconnect structures and methods of formation

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This Patent Application claims priority to U.S. Provisional Patent Application No. 63/263,411, filed on Nov. 2, 2021, and entitled “SEMICONDUCTOR INTERCONNECT STRUCTURES AND METHODS OF FORMATION.” The disclosure of the prior Application is considered part of and is incorporated by reference into this Patent Application. 
    
    
     BACKGROUND 
     An electronic device (e.g., a processor, a memory) may include various intermediate and backend layers or regions in which individual semiconductor devices (e.g., transistors, capacitors, resistors) are interconnected by interconnect structures. The interconnect structures may include metallization layers (also referred to as wires), vias that connect the metallization layers, contact plugs, and/or trenches, among other examples. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is noted that, in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion. 
         FIG.  1    is a diagram of an example environment in which systems and/or methods described herein may be implemented. 
         FIG.  2    is a diagram of an example of a portion of a semiconductor device described herein. 
         FIGS.  3 - 6    are diagrams of example implementations of semiconductor structures described herein. 
         FIGS.  7 A- 7 G,  8 A- 7 F,  9 A- 9 F, and  10 A- 10 F  are diagrams of example implementations described herein. 
         FIGS.  11  and  12 A- 12 D  are diagrams of other example implementations of a portion of the semiconductor device of  FIG.  2    described herein. 
         FIG.  13    is a diagram of example components of one or more devices of  FIG.  1    described herein. 
         FIGS.  14  and  15    are flowcharts of example processes relating to forming a semiconductor interconnect structure described herein. 
     
    
    
     DETAILED DESCRIPTION 
     The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. 
     Further, spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly. 
     In the semiconductor industry, there are continued efforts to reduce the size of integrated circuits (ICs) and structures included therein (e.g., transistors, contacts, interconnects). The reduction in IC can be facilitated through the reduction in horizontal width of the structures included therein, which leads to an increase in aspect ratio (e.g., between height/depth and width) of the structures. This enables greater device density, reduced power, and greater IC performance. However, shrinking structure sizes and increased aspect ratios magnify the effects of semiconductor manufacturing defects, such as voids, cracks, discontinuities, and/or impurities. These defects can increase contact resistance, can lead to premature device failure, and can lead to reduced manufacturing yield, among other examples. Moreover, these defects can be worsened by subsequent processes such as CMP and plasma-based etching. 
     Some implementations described herein provide two-step anneal techniques in which an interconnect structure (e.g., a gate interconnect (via-to-gate, VG) or a source/drain interconnect (via-to-source/drain, VD)) is formed by performing a first anneal operation on a first portion of the interconnect, filling the remaining portion of the interconnect, and then performing a second anneal operation on the interconnect. The first portion of the interconnect is annealed in the first anneal operation to remove defects (such as voids) that might otherwise be unreachable from the top of the interconnect due to the high aspect ratio of the interconnect. The two-step anneal techniques described herein enable the removal of defects (e.g., voids) in an interconnect structure, particularly for high aspect ratio interconnect structures. Accordingly, the two-step anneal techniques described herein may be used to fabricate defect free or near defect free interconnect structures in a semiconductor device. This reduces contact resistance for the interconnect structures, reduces premature device failure for the semiconductor device, increases manufacturing yield, and increases tolerance of the interconnect structures to subsequent processing operations, among other examples. 
       FIG.  1    is a diagram of an example environment  100  in which systems and/or methods described herein may be implemented. As shown in  FIG.  1   , environment  100  may include a plurality of semiconductor processing tools  102 - 114  and a wafer/die transport tool  116 . The plurality of semiconductor processing tools  102 - 114  may include a deposition tool  102 , an exposure tool  104 , a developer tool  106 , an etch tool  108 , a planarization tool  110 , a plating tool  112 , an annealing tool  114 , and/or another type of semiconductor processing tool. The tools included in example environment  100  may be included in a semiconductor clean room, a semiconductor foundry, a semiconductor processing facility, and/or manufacturing facility, among other examples. 
     The deposition tool  102  is a semiconductor processing tool that includes a semiconductor processing chamber and one or more devices capable of depositing various types of materials onto a substrate. In some implementations, the deposition tool  102  includes a spin coating tool that is capable of depositing a photoresist layer on a substrate such as a wafer. In some implementations, the deposition tool  102  includes a chemical vapor deposition (CVD) tool such as a plasma-enhanced CVD (PECVD) tool, a high-density plasma CVD (HDP-CVD) tool, a sub-atmospheric CVD (SACVD) tool, an atomic layer deposition (ALD) tool, a plasma-enhanced atomic layer deposition (PEALD) tool, or another type of CVD tool. In some implementations, the deposition tool  102  includes a physical vapor deposition (PVD) tool, such as a sputtering tool or another type of PVD tool. In some implementations, the example environment  100  includes a plurality of types of deposition tools  102 . 
     The exposure tool  104  is a semiconductor processing tool that is capable of exposing a photoresist layer to a radiation source, such as an ultraviolet light (UV) source (e.g., a deep UV light source, an extreme UV light (EUV) source, and/or the like), an x-ray source, an electron beam (e-beam) source, and/or the like. The exposure tool  104  may expose a photoresist layer to the radiation source to transfer a pattern from a photomask to the photoresist layer. The pattern may include one or more semiconductor device layer patterns for forming one or more semiconductor devices, may include a pattern for forming one or more structures of a semiconductor device, may include a pattern for etching various portions of a semiconductor device, and/or the like. In some implementations, the exposure tool  104  includes a scanner, a stepper, or a similar type of exposure tool. 
     The developer tool  106  is a semiconductor processing tool that is capable of developing a photoresist layer that has been exposed to a radiation source to develop a pattern transferred to the photoresist layer from the exposure tool  104 . In some implementations, the developer tool  106  develops a pattern by removing unexposed portions of a photoresist layer. In some implementations, the developer tool  106  develops a pattern by removing exposed portions of a photoresist layer. In some implementations, the developer tool  106  develops a pattern by dissolving exposed or unexposed portions of a photoresist layer through the use of a chemical developer. 
     The etch tool  108  is a semiconductor processing tool that is capable of etching various types of materials of a substrate, wafer, or semiconductor device. For example, the etch tool  108  may include a wet etch tool, a dry etch tool, and/or the like. In some implementations, the etch tool  108  includes a chamber that is filled with an etchant, and the substrate is placed in the chamber for a particular time period to remove particular amounts of one or more portions of the substrate. In some implementations, the etch tool  108  may etch one or more portions of the substrate using a plasma etch or a plasma-assisted etch, which may involve using an ionized gas to isotropically or directionally etch the one or more portions. 
     The planarization tool  110  is a semiconductor processing tool that is capable of polishing or planarizing various layers of a wafer or semiconductor device. For example, a planarization tool  110  may include a chemical mechanical planarization (CMP) tool and/or another type of planarization tool that polishes or planarizes a layer or surface of deposited or plated material. The planarization tool  110  may polish or planarize a surface of a semiconductor device with a combination of chemical and mechanical forces (e.g., chemical etching and free abrasive polishing). The planarization tool  110  may utilize an abrasive and corrosive chemical slurry in conjunction with a polishing pad and retaining ring (e.g., typically of a greater diameter than the semiconductor device). The polishing pad and the semiconductor device may be pressed together by a dynamic polishing head and held in place by the retaining ring. The dynamic polishing head may rotate with different axes of rotation to remove material and even out any irregular topography of the semiconductor device, making the semiconductor device flat or planar. 
     The plating tool  112  is a semiconductor processing tool that is capable of plating a substrate (e.g., a wafer, a semiconductor device, and/or the like) or a portion thereof with one or more metals. For example, the plating tool  112  may include a copper electroplating device, an aluminum electroplating device, a nickel electroplating device, a tin electroplating device, a compound material or alloy (e.g., tin-silver, tin-lead, and/or the like) electroplating device, and/or an electroplating device for one or more other types of conductive materials, metals, and/or similar types of materials. 
     The annealing tool  114  is a semiconductor processing tool that includes a semiconductor processing chamber and one or more devices capable of heating a semiconductor substrate or semiconductor device. For example, the annealing tool  114  may include a rapid thermal annealing (RTA) tool or another type of annealing tool that is capable of heating a semiconductor substrate to cause a reaction between two or more materials or gasses, to cause a material to decompose. As another example, the annealing tool  114  is configured to heat (e.g., raise or elevate the temperature of) metal structures (or portions thereof) to re-flow the metal structures (e.g., to cause the metal structures to transition from solid form to liquid form, or a form in which the material of the metal structures is enabled to flow) to remove defects from the metal structures, as described herein. 
     The wafer/die transport tool  116  includes a mobile robot, a robot arm, a tram or rail car, an overhead hoist transport (OHT) system, an automated materially handling system (AMHS), and/or another type of device that is used to transport wafers and/or dies between semiconductor processing tools  102 - 114  and/or to and from other locations such as a wafer rack, a storage room, and/or the like. In some implementations, the wafer/die transport tool  116  may be a programmed device that is configured to travel a particular path and/or may operate semi-autonomously or autonomously. 
     The number and arrangement of devices shown in  FIG.  1    are provided as one or more examples. In practice, there may be additional devices, fewer devices, different devices, or differently arranged devices than those shown in  FIG.  1   . Furthermore, two or more devices shown in  FIG.  1    may be implemented within a single device, or a single device shown in  FIG.  1    may be implemented as multiple, distributed devices. Additionally, or alternatively, a set of devices (e.g., one or more devices) of environment  100  may perform one or more functions described as being performed by another set of devices of environment  100 . 
       FIG.  2    is a diagram of a portion of a semiconductor device  200  described herein. The portion of the semiconductor device  200  includes an example of a memory device (e.g., a static random access memory (SRAM), a dynamic random access memory (DRAM)), a logic device, a processor, an input/output device, or another type of semiconductor device that includes one or more transistors. 
     As shown in  FIG.  2   , the semiconductor device  200  includes a device substrate  202 , which includes a silicon (Si) substrate, a substrate formed of a material including silicon, a III-V compound semiconductor material substrate such as gallium arsenide (GaAs), a silicon on insulator (SOI) substrate, a silicon germanium (SiGe) substrate, or another type of semiconductor substrate. In some implementations, a fin structure  204  is formed in the device substrate  202 . In some implementations, a plurality of fin structures  204  are included in the device substrate  202 . In this way, the transistors included on the semiconductor device  200  include fin field-effect transistors (finFETs). In some implementations, the semiconductor device  200  includes other types of transistors, such as gate all around (GAA) transistors (e.g., nanosheet transistors, nanowire transistors, nanostructure transistors), planar transistors, and/or other types of transistors. The fin structures  204  are electrically isolated by intervening shallow trench isolation (STI) structures or regions (not shown). The STI structures may be etched back such that the height of the STI structures is less than the height of the fin structures  204 . In this way, the gate structures of the transistors may be formed around at least three sides of the fin structures  204 . 
     As shown in  FIG.  2   , a plurality of layers are included on the device substrate  202  and/or on the fin structures  204 , including a dielectric layer  206 , an etch stop layer (ESL)  208 , and a dielectric layer  210 , among other examples. The dielectric layers  206  and  210  are included to electrically isolate various structures of the semiconductor device  200 . The dielectric layers  206  and  210  include interlayer dielectric layers (ILDs). For example, the dielectric layer  206  may include an ILDO layer, and the dielectric layer  210  may include an ILD 1  layer or an ILD 2  layer (in some cases, the ILD 1  layer is skipped). 
     The thickness of the dielectric layer  210  may be included in a range of approximately 3 nanometers to approximately 40 nanometers to provide sufficient height or depth for forming the interconnect structures of the semiconductor device  200  without unduly increasing the height of the semiconductor device  200 . However, other values for the thickness of the ESL  208  are within the scope of the present disclosure. The dielectric layers  206  and  210  each include (e.g., either the same material or different materials) a lanthanum oxide (La x O y ), an aluminum oxide (Al x O y ), a yttrium oxide (Y x O y ), a tantalum carbon nitride (TaCN), a zirconium silicide (ZrSix), a silicon oxycarbonitride (SiOCN), a silicon oxycarbide (SiOC), a silicon carbon nitride (SiCN), a zirconium nitride (ZrN), a zirconium aluminum oxide (ZrAlO), a titanium oxide (Ti x O y ), a tantalum oxide (Ta x O y ), a zirconium oxide (ZrxO y ), a hafnium oxide (HfxO y ), a silicon nitride (Si x N y ), a hafnium silicide (HfSi x ), an aluminum oxynitride (AlON), a silicon oxide (Si x O y ), a silicon carbide (SiC), a zinc oxide (Zn x O y ), and/or another dielectric material. 
     The thickness of the ESL  208  may be included in a range of approximately 3 nanometers to approximately 20 nanometers to provide sufficient etch selectivity without unduly increasing the height of the semiconductor device  200 . However, other values for the thickness of the ESL  208  are within the scope of the present disclosure. The ESL  208  includes a layer of material that is configured to permit various portions of the semiconductor device  200  (or the layers included therein) to be selectively etched or protected from etching to form one or more of the structures included on the device substrate  202 . The ESL  208  may include a lanthanum oxide (La x O y ), an aluminum oxide (Al x O y ), a yttrium oxide (Y x O y ), a tantalum carbon nitride (TaCN), a zirconium silicide (ZrSix), a silicon oxycarbonitride (SiOCN), a silicon oxycarbide (SiOC), a silicon carbon nitride (SiCN), a zirconium nitride (ZrN), a zirconium aluminum oxide (ZrAlO), a titanium oxide (Ti x O y ), a tantalum oxide (Ta x O y ), a zirconium oxide (Zr x O y ), a hafnium oxide (Hf x O y ), a silicon nitride (Si x N y ), a hafnium silicide (HfSi x ), an aluminum oxynitride (AlON), a silicon oxide (Si x O y ), a silicon carbide (SiC), and/or a zinc oxide (Zn x O y ), among other examples. 
     As further shown in  FIG.  2   , a plurality of gate stacks may be included over, on, and/or around a portion of the fin structure  204 . The gate stacks include a metal gate (MG) structure  212  between sidewall spacers  214 , a metal capping layer  216  over and/or on the metal gate structure  212 , and a dielectric capping layer  218  over and/or on the metal capping layer  216 . The metal gate structures  212  include a conductive metallic material (or metal alloy) such as cobalt (Co), tungsten (W), ruthenium (Ru), molybdenum (Mo), titanium (Ti), titanium nitride (TiN), another metallic material, and/or a combination thereof. The sidewall spacers  214  are included to electrically isolate the gate stacks from adjacent conductive structures included on the semiconductor device  200 , and thus may be referred to as gate spacers. The sidewall spacers  214  include a silicon oxide (SiO x ), a silicon nitride (Si x N y ), a silicon oxy carbide (SiOC), a silicon oxycarbonitride (SiOCN), and/or another suitable material. 
     The metal capping layer  216  is included to protect the metal gate structure  212  from oxidization and/or etch damage during processing of the semiconductor device  200 , which preserves the low contact resistance of the metal gate structure  212 . The metal capping layer  216  include a conductive metallic material (or metal alloy) such as cobalt (Co), tungsten (W), ruthenium (Ru), molybdenum (Mo), titanium (Ti), titanium nitride (TiN), another metallic material, and/or a combination thereof. The dielectric capping layer  218  includes a dielectric material such as a lanthanum oxide (La x O y ), an aluminum oxide (Al x O y ), a yttrium oxide (Y x O y ), a tantalum carbon nitride (TaCN), a zirconium silicide (ZrSi x ), a silicon oxycarbonitride (SiOCN), a silicon oxycarbide (SiOC), a silicon carbon nitride (SiCN), a zirconium nitride (ZrN), a zirconium aluminum oxide (ZrAlO), a titanium oxide (Ti x O y ), a tantalum oxide (Ta x O y ), a zirconium oxide (Zr x O y ), a hafnium oxide (Hf x O y ), a silicon nitride (Si x N y ), a hafnium silicide (HfSi x ), an aluminum oxynitride (AlON), a silicon oxide (Si x O y ), a silicon carbide (SiC), and/or a zinc oxide (Zn x O y ), among other examples. 
     The dielectric capping layer  218  may be referred to as a sacrificial (SAC) layer that protects the gate stacks from processing damage during processing of the semiconductor device  200 . In some implementations, the dielectric capping layer  218  includes a first portion  218   a  (e.g., a lower portion) between a pair of sidewall spacers  214 , where the first portion  218   a  extends from a top surface of an associated metal capping layer  216  to the same approximately height or top surface level of the sidewall spacers  214 . In these implementations, the dielectric capping layer  218  further includes a second portion  218   b  (e.g., an upper portion) that extends above the first portion  218   a  and over the top surfaces of the sidewall spacers  214 , as shown in  FIG.  2   . In some other implementations, the sidewall spacers  214  fully extend between the fin structure  204  (or the device substrate  202 ) and the ESL  208 , and the dielectric capping layer  218  is fully contained between the sidewall spacers  214  between the top surface of the associated metal capping layer  216  and the bottom surface of the ESL  208 . 
     As further shown in  FIG.  2   , a plurality of source/drain regions  220  are included on and/or around portions of the fin structure  204 . The source/drain regions  220  include p-doped and/or n-doped epitaxial (epi) regions that are grown and/or otherwise formed by epitaxial growth. In some implementations, the source/drain regions  220  are formed over etched portions of the fin structure  204 . The etched portions may be formed by strained source drain (SSD) etching of the fin structure  204  and/or another type etching operation. 
     Metal source/drain contacts (MDs)  222  are included over and/or on the source/drain regions  220 . In some implementations, a metal silicide layer (not shown) is included between the source/drain regions  220  and the metal source/drain contacts  222  due to a reaction between the source/drain regions  220  and the metal source/drain contacts  222 . The metal silicide layer may be included to decrease contact resistance between the source/drain regions  220  and the metal source/drain contacts  222  and/or to decrease the Schottky barrier height (SBH) between the source/drain regions  220  and the metal source/drain contacts  222 . The metal source/drain contacts  222  include conductive metallic material (or metal alloy) such as cobalt (Co), tungsten (W), ruthenium (Ru), copper (Cu), another metallic material, and/or a combination thereof. 
     In some implementations, a contact etch stop layer (CESL) is included between the sidewall spacers of the gate stacks and the metal source/drain contacts  222 . The CESL may be included to provide etch selectivity or etch stop point for the sidewall spacers  214  during an etch operation to form openings in which the metal source/drain contacts  222  are formed. 
     As further shown in  FIG.  2   , the metal gate structures  212  (e.g., either directly or via the metal capping layer  216 ) and the metal source/drain contacts  222  are electrically and/or physically connected to interconnect structures. For example, a metal gate structure  212  may be electrically connected to a gate interconnect structure  224  (e.g., a gate via or VG). The metal gate structure  212  is electrically and/or physically connected to the gate interconnect structure  224  directly, via the intervening metal capping layer  216 , and/or by a metal gate contact (MP). As another example, a metal source/drain contact  222  are electrically and/or physically connected to a source/drain interconnect structure  226  (e.g., a source/drain via or VD). The interconnect structures (e.g., the gate interconnect structure  224 , the source/drain interconnect structure  226 , among other examples) electrically connect the transistors on the semiconductor device  200  and/or electrically connect the transistors to other areas and/or components of the semiconductor device  200 . In some implementations, the interconnect structures electrically connect the transistors to a back end of line (BEOL) region of the semiconductor device  200 . The gate interconnect structure  224  and the source/drain interconnect structure  226  include a conductive material such as tungsten, cobalt, ruthenium, copper, and/or another type of conductive material. 
     As further shown in  FIG.  2   , the gate interconnect structure  224  includes a two-part structure including a first part  224   a  and a second part  224   b . The first part  224   a  is orientated toward the metal gate structure  212  and is electrically (and/or physically) connected with the metal gate structure  212  either directly or by the metal capping layer  216  (e.g., where metal capping layer  216  functions as an intervening conductive layer, and the top surface of the metal capping layer  216  is lower than the top surfaces of the associated sidewall spacers  214 ). The second part  224   b  is included over and/or on the first part  224   a . In some implementations, the height or thickness of the first part  224   a  and/or the height or thickness of the second part  224   b  is greater relative to a height or thickness of the metal capping layer  216 . In some implementations, the height or vertical position of a top surface of the first part  224   a  and/or the height or vertical position of a top surface of the second part  224   b  is greater relative to a height or vertical position of a top surface of the metal source/drain contact  222 . 
     As described herein, the first part  224   a  and the second part  224   b  are formed by respective and separate deposition operations, which result in the two-part structure of the gate interconnect structure  224 . As a result, an interface between the first part  224   a  and the second part  224   b  is located at a location along the depth (or height) of the gate interconnect structure  224 . The interface may be visible in the electron microscope imaging of the gate interconnect structure  224  (e.g., in a transmission electron microscopy (TEM) image of the gate interconnect structure  224 ) as a result of, for example, slight oxidation or nitridation at the top surface of the first part  224   a  prior to deposition of the second part  224   b . While the interface is shown as being located at the same level as the dielectric layer  210  (e.g., at a height or depth that is between the bottom surface and the top surface of the dielectric layer  210 ), the first part  224   a  and the second part  224   b  may be formed such that the interface is located at another level in the semiconductor device  200  such as at the same level as the ESL  208  or the same level as the dielectric capping layer  218  (e.g., the first portion  218   a  or the second portion  218   b ), among other examples. The location of the interface between the first part  224   a  and the second part  224   b  may be based on a height of the gate interconnect structure  224 , a width of the gate interconnect structure  224 , an aspect ratio of the gate interconnect structure  224 , a type of material that is used to form the first part  224   a , a type of material that is used to form the second part  224   b , and/or another factor. 
     The formation of the first part  224   a  and the second part  224   b  by respective and separate deposition operations further enables the first part  224   a  and the second part  224   b  to be formed of different conductive materials or different conductive material compositions including one or more conductive materials. For example, the first part  224   a  may include a first conductive material composition including one or more first conductive materials, the second part  224   b  may include a second conductive material composition including one or more second conductive materials, where the first conductive material composition and the second conductive material composition are different material compositions. This enables further flexibility in the semiconductor processes of forming the gate interconnect structure  224  and enables the formation of more complex and higher performance gate interconnect structures  224 . Although, the first part  224   a  and the second part  224   b  being formed of the same material or same material composition is within the scope of the present disclosure. In some implementations, the first part  224   a  includes a conductive material such as tungsten (W), ruthenium (Ru), molybdenum (Mo), cobalt (Co), copper (Cu), another conductive material, a conductive material composition of one or more of the preceding conductive materials, or a combination thereof. In some implementations, the second part  224   b  includes a conductive material such as tungsten (W), ruthenium (Ru), molybdenum (Mo), cobalt (Co), copper (Cu), aluminum (Al), titanium (Ti), titanium nitride (TiN), another conductive material, a conductive material composition of one or more of the preceding conductive materials, or a combination thereof. 
     In some implementations, the grain size of the material of the first part  224   a  and the grain size of the material of the second part  224   b  are approximately the same grain size. In some implementations, the grain size of the material of the first part  224   a  and the grain size of the material of the second part  224   b  are different grain sizes. For example, the grain size of the material of the first part  224   a  may be greater than the grain size of the material of the second part  224   b . As another example, the grain size of the material of the second part  224   b  may be greater than the grain size of the material of the first part  224   a.    
     As further shown in  FIG.  2   , the source/drain interconnect structure  226  includes a two-part structure including a first part  226   a  and a second part  226   b .The first part  226   a  is orientated toward an associated metal source/drain contact  222  and is electrically (and/or physically) connected with the metal source/drain contact  222  either directly or by one or more liners and/or barrier layers. The second part  226   b  is included over and/or on the first part  226   a . In some implementations, the height or vertical position of a top surface of the first part  226   a  and/or the height or vertical position of a top surface of the second part  226   b  is greater relative to a height or vertical position of a top surface the metal capping layer  216 . In some implementations, the height or thickness of the first part  226   a  and/or the height or thickness of the second part  226   b  is greater relative to a height or thickness of the metal source/drain contact  222 . 
     As described herein, the first part  226   a  and the second part  226   b  are formed by respective and separate deposition operations, which results in the two-part structure of the source/drain interconnect structure  226 . As a result, an interface between the first part  226   a  and the second part  226   b  is located at a location along the depth (or height) of the source/drain interconnect structure  226 . The interface may be visible in the electron microscope imaging of the gate interconnect structure  224  (e.g., in a TEM image of the source/drain interconnect structure  226  as a result of, for example, slight oxidation or nitridation at the top surface of the first part  226   a  prior to deposition of the second part  226   b .While the interface is shown as being located at the same level as the dielectric layer  210  (e.g., at a height or depth that is between the bottom surface and the top surface of the dielectric layer  210 ), the first part  226   a  and the second part  226   b  may be formed such that interface is located at another level in the semiconductor device  200  such as at the same level as the ESL  208 , among other examples. The location of the interface between the first part  226   a  and the second part  226   b  may be based on a height of the source/drain interconnect structure  226 , a width of the source/drain interconnect structure  226 , an aspect ratio of the source/drain interconnect structure  226 , a type of material that is used to form the first part  226   a , a type of material that is used to form the second part  226   b , and/or another factor. 
     In some implementations, the interface between the first part  224   a  and the second part  224   b  of the gate interconnect structure  224 , and the interface between the first part  226   a  and the second part  226   b  of the source/drain interconnect structure  226 , are located at the same height or the same vertical positions in the semiconductor device  200 . In some implementations, the interface between the first part  224   a  and the second part  224   b  of the gate interconnect structure  224 , and the interface between the first part  226   a  and the second part  226   b  of the source/drain interconnect structure  226 , may be located at different heights or at different vertical positions in the semiconductor device  200 . In some implementations, the height or vertical position of the interface between the first part  226   a  and the second part  226   b  of the source/drain interconnect structure  226  is greater than the height or vertical position of the interface between the first part  224   a  and the second part  224   b  of the gate interconnect structure  224 . In some implementations, the height or vertical position of the interface between the first part  224   a  and the second part  224   b  of the gate interconnect structure  224  is greater than height or vertical position of the interface between the first part  226   a  and the second part  226   b  of the source/drain interconnect structure  226 . In some implementations, the difference between the height or vertical position of the interface between the first part  226   a  and the second part  226   b  of the source/drain interconnect structure  226  and the height or vertical position of the interface between the first part  224   a  and the second part  224   b  of the gate interconnect structure  224  is in a range of approximately 2 nanometers to approximately 15 nanometers. However, other values for the difference are within the scope of the present disclosure. 
     The formation of the first part  226   a  and the second part  226   b  by respective and separate deposition operations further enables the first part  226   a  and the second part  226   b  to be formed of different conductive materials or different conductive material compositions including one or more conductive materials. For example, the first part  226   a  may include a first conductive material composition including one or more first conductive materials, the second part  226   b  may include a second conductive material composition including one or more second conductive materials, where the first conductive material composition and the second conductive material composition are different material compositions. This enables further flexibility in the semiconductor processes of forming the source/drain interconnect structure  226  and enables the formation of more complex and higher performance source/drain interconnect structures  226 . Although, the first part  226   a  and the second part  226   b  being formed of the same material or same material composition is within the scope of the present disclosure. In some implementations, the first part  226   a  includes a conductive material such as tungsten (W), ruthenium (Ru), molybdenum (Mo), cobalt (Co), copper (Cu), another conductive material, a conductive material composition of one or more of the preceding conductive materials, or a combination thereof. In some implementations, the second part  226   b  includes a conductive material such as tungsten (W), ruthenium (Ru), molybdenum (Mo), cobalt (Co), copper (Cu), aluminum (Al), titanium (Ti), titanium nitride (TiN), another conductive material, a conductive material composition of one or more of the preceding conductive materials, or a combination thereof. 
     In some implementations, the grain size of the material of the first part  226   a  and the grain size of the material of the second part  226   b  are approximately the same grain size. In some implementations, the grain size of the material of the first part  226   a  and the grain size of the material of the second part  226   b  are different grain sizes. For example, the grain size of the material of the first part  226   a  may be greater than the grain size of the material of the second part  226   b .As another example, the grain size of the material of the second part  226   b  may be greater than the grain size of the material of the first part  226   a.    
     As indicated above,  FIG.  2    is provided as an example. Other examples may differ from what is described with regard to  FIG.  2   . 
       FIG.  3    is a diagram of an example implementation  300  of semiconductor structures described herein. The example implementation  300  includes various dimensions and/or parameters of a metal gate structure  212 , of a plurality of sidewall spacers  214 , of a metal capping layer  216 , and of a dielectric capping layer  218  included in the semiconductor device  200 . 
     As shown in  FIG.  3   , an example dimension  302  includes a width of the metal gate structure  212 . In some implementations, the width of the metal gate structure  212  is included in a range of approximately 2 nanometers to approximately 50 nanometers to provide sufficient transistor channel control while enabling transistors to be densely integrated into the semiconductor device  200 . However, other values for the width of the metal gate structure  212  are within the scope of the present disclosure. In some implementations, an aspect ratio between the width of the metal gate structure  212  and a height of the metal gate structure  212  is included in a range of approximately 1:1 to approximately 1:3 to provide sufficient transistor channel control while enabling transistors to be densely integrated into the semiconductor device  200 . However, other values for the ratio are within the scope of the present disclosure. 
     As further shown in  FIG.  3   , an example dimension  304  includes a thickness of the metal capping layer  216 . In some implementations, the thickness of the metal capping layer  216  is included in a range of approximately 1 nanometer to approximately 10 nanometers to achieve continuity and uniformity for the metal capping layer  216 , to provide sufficient protection of the metal gate structure  212 , and/or to achieve a sufficiently low contact resistance between the metal gate structure  212  and the gate interconnect structure  224 . However, other values of the thickness of the metal capping layer are within the scope of the present disclosure. 
     As further shown in  FIG.  3   , and example dimension  306  includes a thickness of the first portion  218   a  of the dielectric capping layer  218 . In some implementations, the thickness of the first portion  218   a  is included in a range of approximately 1 nanometer to approximately 50 nanometers such that the height of the first portion  218   a  is approximately equal to the height of the top surfaces of the sidewall spacers  214 . However, other values for the thickness of the first portion are within the scope of the present disclosure. 
     As further shown in  FIG.  3   , and example dimension  308  includes a thickness of the second portion  218   b  of the dielectric capping layer  218 . In some implementations, the thickness of the second portion  218   b  is included in a range of approximately 1 nanometer to approximately 30 nanometers such that the overall thickness of the dielectric capping layer  218  provides sufficient protection for the metal gate structure  212  and/or the metal capping layer  216 . However, other values for the thickness of the first portion are within the scope of the present disclosure. 
     As indicated above,  FIG.  3    is provided as examples. Other examples may differ from what is described with regard to  FIG.  3   . 
       FIG.  4    is a diagram of an example implementation  400  of a semiconductor structure described herein. The example implementation  400  includes various dimensions and/or parameters of a metal source/drain contact  222  included in the semiconductor device  200 . 
     As shown in  FIG.  4   , an example dimension  402  includes a thickness or height of the metal source/drain contact  222 . In some implementations, the thickness or height of the metal source/drain contact  222  is included in a range of approximately 10 nanometers to approximately 80 nanometers to connect the metal source/drain contact  222  to an associated source/drain region  220  and such that a height of a top surface of the metal source/drain contact  222  and a height of a top surface of an associated dielectric capping layer  218  included in the semiconductor device  200  are approximately equal. However, other values for the thickness or height of the metal source/drain contact  222  are within the scope of the present disclosure. 
     As further shown in  FIG.  4   , an example dimension  404  includes a bottom width of the metal source/drain contact  222 . In some implementations, the bottom width of the metal source/drain contact  222  is included in a range of approximately 10 nanometers to approximately 25 nanometers to provide sufficient contact area between the metal source/drain contact  222  and an associated source/drain region  220  of the semiconductor device  200  for contact resistance performance while enabling increased transistor integration in the semiconductor device  200 . However, other values for the bottom width of the metal source/drain contact  222  are within the scope of the present disclosure. 
     As further shown in  FIG.  4   , an example dimension  406  includes a top width of the metal source/drain contact  222 . In some implementations, the top width of the metal source/drain contact  222  is included in a range of approximately 11 nanometers to approximately 27 nanometers to provide sufficient contact area between the metal source/drain contact  222  and an associated source/drain interconnect structure  226  for contact resistance performance while enabling increased transistor integration in the semiconductor device  200 . However, other values for the top width of the metal source/drain contact  222  are within the scope of the present disclosure. 
     In some implementations, an aspect ratio between a width of the metal source/drain contact  222  (e.g., the bottom width or the top width) and the thickness or height of the metal source/drain contact  222  is included in a range of approximately 1:1 to approximately 1:3 to enable increased transistor integration in the semiconductor device  200  while achieving sufficient gap-filling performance for the metal source/drain contact  222 . However, other values for the ratio are within the scope of the present disclosure. 
     As further shown in  FIG.  4   , an example dimension  408  includes a depth of a recess  410  included in the metal source/drain contact  222  (e.g., included in a top portion of the metal source/drain contact  222 ). The recess  410  may be included in the top portion of the metal source/drain contact  222  to provide increased surface area for connection between the metal source/drain contact  222  and an associated source/drain interconnect structure  226 . In some implementations, the depth of the recess  410  is included in a range of approximately 0.5 nanometers to approximately 3 nanometers to provide sufficient surface contact area for the associated source/drain interconnect structure  226  while minimizing damage to the metal source/drain contact  222 . However, other values for the depth are within the scope of the present disclosure. 
     As indicated above,  FIG.  4    is provided as examples. Other examples may differ from what is described with regard to  FIG.  4   . 
       FIG.  5    is a diagram of an example implementation  500  of a semiconductor structure described herein. The example implementation  500  includes various dimensions and/or parameters of a gate interconnect structure  224  included in the semiconductor device  200 . In particular, the example implementation  500  includes various dimensions and/or parameters of a two-part gate interconnect structure  224  described herein, including a first part  224   a  and a second part  224   b.    
     As shown in  FIG.  5   , an example dimension  502  includes an overall thickness or height of the gate interconnect structure  224 . In some implementations, the overall thickness or height of the gate interconnect structure  224  is included in a range of approximately 10 nanometers to approximately 80 nanometers based on the thickness of the ESL  208 , the thickness of the dielectric layer  210 , whether the gate interconnect structure is connected directly to a metal gate structure  212  or by a metal capping layer  216 , and/or based on other parameters. However, other values for the overall thickness or height of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  504  includes a thickness or height of the first part  224   a  of the gate interconnect structure  224 . In some implementations, the thickness or height of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 5 nanometers to approximately 40 nanometers. In some implementations, the thickness or height of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 5 nanometers to approximately 20 nanometers. In some implementations, the thickness or height of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 21 nanometers to approximately 40 nanometers. The thickness or height of the first part  224   a  of the gate interconnect structure  224  may be configured in one or more of these ranges may provide sufficient defect migration and/or removal, as described herein. However, other values for the thickness or height of the first part  224   a  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  506  includes a thickness or height of the second part  224   b  of the gate interconnect structure  224 . In some implementations, the thickness or height of the second part  224   b  of the gate interconnect structure  224  is included in a range of approximately 5 nanometers to approximately 40 nanometers to provide sufficient defect migration and/or removal, as described herein. However, other values for the thickness or height of the second part  224   b  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  508  includes a bottom width of the first part  224   a  of the gate interconnect structure  224  (which also corresponds to the bottom width of the gate interconnect structure  224 ). In some implementations, the bottom width of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 2 nanometers to approximately 18 nanometers. In some implementations, the bottom width of the of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 2 nanometers to approximately 6 nanometers. In some implementations, the bottom width of the of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 8 nanometers to approximately 18 nanometers. The bottom width of the first part  224   a  of the gate interconnect structure  224  may be included in one or more of these ranges to provide sufficient contact area between the gate interconnect structure  224  and an associated metal gate structure  212  (or metal capping layer  216 ) of the semiconductor device  200  for contact resistance performance while enabling increased transistor integration in the semiconductor device  200 . However, other values for the bottom width of the first part  224   a  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  510  includes a top width of the first part  224   a  of the gate interconnect structure  224 . In some implementations, the top width of the of the first part  224   a  of the gate interconnect structure  224  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the height or thickness of the first part  224   a  (e.g., which corresponds to the example dimension  504 ) and the taper of the gate interconnect structure  224 . However, other values for the top width of the first part  224   a  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  512  includes a bottom width of the second part  224   b  of the gate interconnect structure  224 . In some implementations, the bottom width of the of the second part  224   b  of the gate interconnect structure  224  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the height or thickness of the first part  224   a  (e.g., which corresponds to the example dimension  504 ) and the taper of the gate interconnect structure  224 . However, other values for the bottom width of the second part  224   b  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an example dimension  514  includes a top width of the second part  224   b  of the gate interconnect structure  224 . In some implementations, the top width of the of the second part  224   b  of the gate interconnect structure  224  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the overall height of the gate interconnect structure  224  (e.g., which corresponds to the example dimension  502 ) and the taper of the gate interconnect structure  224 . However, other values for the top width of the second part  224   b  of the gate interconnect structure  224  are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , an interface  516  is included between the first part  224   a  of the gate interconnect structure  224  and the second part  224   b  of the gate interconnect structure  224 . The interface  516  is curved (or approximately curved) and/or otherwise non-straight-lined, which results from the two-step anneal techniques described herein to remove defects (e.g., voids, gaps, cracks, sidewall slits, discontinuities, and/or other types of defects) from the first part  224   a  and from the second part  224   b  during formation of the gate interconnect structure  224 . In particular, an annealing operation is performed on the first part  224   a  to drive out and/or otherwise remove defects from the first part  224   a . The annealing operation performed on the first part  224   a  results in the formation of the curved top surface of the first part  224   a  due to the formation of a meniscus at the top surface of the first part  224   a . The bottom surface of the second part  224   b  is then formed thereon and takes on the form of (or conforms to) the curved top surface of the first part  224   a , thereby resulting in the curved interface  516 . 
     As further shown in  FIG.  5   , an example dimension  518  includes a distance between a center  520  of the curve of the interface  516  and a base  522  of the curve of the interface  516 . The example dimension  518  may also be referred to as a sagitta of the interface  516 , which corresponds to a straight-line distance between the center (e.g., center  520 ) of a circular arc (e.g., the interface  516 ) to a location at the base (e.g., the base  522 ) of the circular arc that is approximately perpendicular to the base of the circular arc. In some implementations, the sagitta may be less than or greater than the radius of the curve or arc of the interface  516 . In some implementations, the distance between a center  520  of the curve of the interface  516  and a base  522  of the curve of the interface  516  is included in a range of greater than 0 nanometers to approximately 3 nanometers as a result of the annealing operation that is performed for the first part  224   a  to remove defects from the first part  224   a . However, other values for the distance are within the scope of the present disclosure. 
     As further shown in  FIG.  5   , the gate interconnect structure  224  is tapered between the top of the second part  224   b  and the bottom of the first part  224   a . In some implementations, the gate interconnect structure  224  is tapered between the top of the second part  224   b  and the bottom of the first part  224   a  in an approximately continuous and uniform manner, as illustrated in the example in  FIG.  5   . However, in other implementations, the gate interconnect structure  224  is tapered between the top of the second part  224   b  and the bottom of the first part  224   a  in a non-linear and/or a non-uniform manner. The taper may include a curved taper, a tiered taper, or another type of non-linear and/or non-uniform taper. A non-linear and/or non-uniform taper may occur, for example, where the recess in which the gate interconnect structure  224  is to be formed is etched through a plurality of different layers having different etch selectivity and/or different etch rates. 
     In some implementations, an aspect ratio between a width of the gate interconnect structure  224  (e.g., the bottom width of the gate interconnect structure  224 , which corresponds to the bottom width of the first part  224   a  and the example dimension  508 , or the top width of the gate interconnect structure  224 , which corresponds to the top width of the second part  224   b  and the example dimension  514 ) and the overall thickness or height of the gate interconnect structure  224  (e.g., which corresponds to the example dimension  502 ) is included in a range of approximately 1:5.5 to approximately 1:8 to enable increased transistor integration in the semiconductor device  200  while achieving sufficient gap-filling performance for the gate interconnect structure  224 . However, other values for the aspect ratio are within the scope of the present disclosure. 
     In some implementations, a ratio between a width of the first part  224   a  of the gate interconnect structure  224  (e.g., the bottom width corresponding to the example dimension  508  or the top width corresponding to the example dimension  510 ) and a width of the second part  224   b  of the gate interconnect structure  224  (e.g., the bottom width corresponding to the example dimension  512  or the top width corresponding to the example dimension  514 ) is included in a range of approximately 1:1 to approximately 1:2 based on the respective heights of the first part  224   a  and the second part  224   b  and the taper of the gate interconnect structure  224 . However, other values for the ratio are within the scope of the present disclosure. 
     In some implementations, a ratio between a volume or area occupied by the first part  224   a  of the gate interconnect structure  224  and a volume or area occupied by the second part  224   b  of the gate interconnect structure  224  is included in a range of approximately 1:2 to approximately 1:4 based on the respective heights of the first part  224   a  and the second part  224   b  and the taper of the gate interconnect structure  224 . However, other values for the ratio are within the scope of the present disclosure. 
     As indicated above,  FIG.  5    is provided as examples. Other examples may differ from what is described with regard to  FIG.  5   . 
       FIG.  6    is a diagram of an example implementation  600  of a semiconductor structure described herein. The example implementation  600  includes various dimensions and/or parameters of a source/drain interconnect structure  226  included in the semiconductor device  200 . In particular, the example implementation  600  includes various dimensions and/or parameters of a two-part source/drain interconnect structure  226  described herein, including a first part  226   a  and a second part  226   b.    
     As shown in  FIG.  6   , an example dimension  602  includes an overall thickness or height of the source/drain interconnect structure  226 . In some implementations, the overall thickness or height of the source/drain interconnect structure  226  is included in a range of approximately 10 nanometers to approximately 80 nanometers based on the thickness of the ESL  208 , the thickness of the dielectric layer  210 , the height of an associated metal source/drain contact  222 , and/or based on other parameters. However, other values for the overall thickness or height of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  604  includes a thickness or height of the first part  226   a  of the source/drain interconnect structure  226 . In some implementations, the thickness or height of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 5 nanometers to approximately 40 nanometers. In some implementations, the thickness or height of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 5 nanometers to approximately 20 nanometers. In some implementations, the thickness or height of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 21 nanometers to approximately 40 nanometers. The thickness or height of the first part  226   a  of the source/drain interconnect structure  226  may be configured in one or more of these ranges may provide sufficient defect migration and/or removal, as described herein. However, other values for the thickness or height of the first part  226   a  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  606  includes a thickness or height of the second part  226   b  of the source/drain interconnect structure  226 . In some implementations, the thickness or height of the second part  226   b  of the source/drain interconnect structure  226  is included in a range of approximately 5 nanometers to approximately 40 nanometers to provide sufficient defect migration and/or removal, as described herein. However, other values for the thickness or height of the second part  226   b  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  608  includes a bottom width of the first part  226   a  of the source/drain interconnect structure  226  (which also corresponds to the bottom width of the source/drain interconnect structure  226 ). In some implementations, the bottom width of the of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 2 nanometers to approximately 18 nanometers. In some implementations, the bottom width of the of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 2 nanometers to approximately 6 nanometers. In some implementations, the bottom width of the of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 8 nanometers to approximately 18 nanometers. The bottom width of the first part  226   a  of the source/drain interconnect structure  226  may be included in one or more of these ranges to provide sufficient contact area between the source/drain interconnect structure  226  and an associated metal source/drain contact  222  of the semiconductor device  200  for contact resistance performance while enabling increased transistor integration in the semiconductor device  200 . However, other values for the bottom width of the first part  226   a  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  610  includes a top width of the first part  226   a  of the source/drain interconnect structure  226 . In some implementations, the top width of the of the first part  226   a  of the source/drain interconnect structure  226  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the height or thickness of the first part  226   a  (e.g., which corresponds to the example dimension  504 ) and the taper of the source/drain interconnect structure  226 . However, other values for the top width of the first part  226   a  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  612  includes a bottom width of the second part  226   b  of the source/drain interconnect structure  226 . In some implementations, the bottom width of the of the second part  226   b  of the source/drain interconnect structure  226  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the height or thickness of the first part  226   a  (e.g., which corresponds to the example dimension  604 ) and the taper of the source/drain interconnect structure  226 . However, other values for the bottom width of the second part  226   b  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an example dimension  614  includes a top width of the second part  226   b  of the source/drain interconnect structure  226 . In some implementations, the top width of the of the second part  226   b  of the source/drain interconnect structure  226  is included in a range of approximately 10 nanometers to approximately 20 nanometers based on the overall height of the source/drain interconnect structure  226  (e.g., which corresponds to the example dimension  602 ) and the taper of the source/drain interconnect structure  226 . However, other values for the top width of the second part  226   b  of the source/drain interconnect structure  226  are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , an interface  616  is included between the first part  226   a  of the source/drain interconnect structure  226  and the second part  226   b  of the source/drain interconnect structure  226 . The interface  616  is curved (or approximately curved) and/or otherwise non-straight-lined, which results from the two-step anneal techniques described herein to remove defects (e.g., voids, gaps, cracks, sidewall slits, discontinuities, and/or other types of defects) from the first part  226   a  and from the second part  226   b  during formation of the source/drain interconnect structure  226 . In particular, an annealing operation is performed on the first part  226   a  to drive out and/or otherwise remove defects from the first part  226   a . The annealing operation performed on the first part  226   a  results in the formation of the curved top surface of the first part  226   a  due to the formation of a meniscus at the top surface of the first part  226   a . The bottom surface of the second part  226   b  is then formed thereon and takes on the form of (or conforms to) the curved top surface of the first part  226   a , thereby resulting in the curved interface  616 . 
     As further shown in  FIG.  6   , an example dimension  618  includes a distance between a center  620  of the curve of the interface  616  and a base  622  of the curve of the interface  616 . The example dimension  618  may also be referred to as a sagitta of the interface  616 , which corresponds to a straight-line distance between the center (e.g., center  620 ) of a circular arc (e.g., the interface  616 ) to a location at the base (e.g., the base  622 ) of the circular arc that is approximately perpendicular to the base of the circular arc. In some implementations, the sagitta may be less than or greater than the radius of the curve or arc of the interface  616 . In some implementations, the distance between a center  620  of the curve of the interface  616  and a base  622  of the curve of the interface  616  is included in a range of greater than 0 nanometers to approximately 3 nanometers as a result of the annealing operation that is performed for the first part  226   a  to remove defects from the first part  226   a . However, other values for the distance are within the scope of the present disclosure. 
     As further shown in  FIG.  6   , the source/drain interconnect structure  226  is tapered between the top of the second part  226   b  and the bottom of the first part  226   a . In some implementations, the source/drain interconnect structure  226  is tapered between the top of the second part  226   b  and the bottom of the first part  226   a  in an approximately continuous and uniform manner, as illustrated in the example in  FIG.  6   . However, in other implementations, the source/drain interconnect structure  226  is tapered between the top of the second part  226   b  and the bottom of the first part  226   a  in a non-linear and/or a non-uniform manner. The taper may include a curved taper, a tiered taper, or another type of non-linear and/or non-uniform taper. A non-linear and/or non-uniform taper may occur, for example, where the recess in which the source/drain interconnect structure  226  is to be formed is etched through a plurality of different layers having different etch selectivity and/or different etch rates. 
     In some implementations, an aspect ratio between a width of the source/drain interconnect structure  226  (e.g., the bottom width of the source/drain interconnect structure  226 , which corresponds to the bottom width of the first part  226   a  and the example dimension  608 , or the top width of the source/drain interconnect structure  226 , which corresponds to the top width of the second part  226   b  and the example dimension  614 ) and the overall thickness or height of the source/drain interconnect structure  226  (e.g., which corresponds to the example dimension  602 ) is included in a range of approximately 1:3.5 to approximately 1:5 to enable increased transistor integration in the semiconductor device  200  while achieving sufficient gap-filling performance for the source/drain interconnect structure  226 . However, other values for the aspect ratio are within the scope of the present disclosure. 
     In some implementations, a ratio between a width of the first part  226   a  of the source/drain interconnect structure  226  (e.g., the bottom width corresponding to the example dimension  608  or the top width corresponding to the example dimension  610 ) and a width of the second part  226   b  of the source/drain interconnect structure  226  (e.g., the bottom width corresponding to the example dimension  612  or the top width corresponding to the example dimension  614 ) is included in a range of approximately 1:1 to approximately 1:2 based on the respective heights of the first part  226   a  and the second part  226   b  and the taper of the source/drain interconnect structure  226 . However, other values for the ratio are within the scope of the present disclosure. 
     In some implementations, a ratio between a volume or area occupied by the first part  226   a  of the source/drain interconnect structure  226  and a volume or area occupied by the second part  226   b  of the source/drain interconnect structure  226  is included in a range of approximately 1:1 to approximately 1:3 based on the respective heights of the first part  226   a  and the second part  226   b  and the taper of the source/drain interconnect structure  226 . However, other values for the ratio are within the scope of the present disclosure. 
     As indicated above,  FIG.  6    is provided as examples. Other examples may differ from what is described with regard to  FIG.  6   . 
       FIGS.  7 A- 7 G  are diagrams of an example implementation  700  described herein. The example implementation  700  includes an example of forming a two-part interconnect structure such as the gate interconnect structure  224  including the first part  224   a  and the second part  224   b  included in the semiconductor device  200  illustrated in  FIG.  2    and/or elsewhere herein. Turning to  FIG.  7 A , one or more operations may be performed to form the fin structure  204 , the metal gate structures  212 , the metal capping layers  216 , the dielectric capping layers  218 , the dielectric layer  206 , and/or the metal source/drain contacts  222 . 
     As shown in  FIG.  7 B , the ESL  208  is formed on the semiconductor device  200 , and the dielectric layer  210  is formed over and/or on the ESL  208 . In some implementations, a deposition tool  102  deposits the ESL  208  and the dielectric layer  210  by a CVD, ALD, PVD, and/or another deposition technique. 
     As shown in  FIG.  7 C , an opening (or a recess)  702  is formed in the dielectric layer  210  and in the ESL  208 . In particular, the opening  702  is formed in the dielectric layer  210 , in the ESL  208 , in a dielectric capping layer  218 , and to conductive layer such as a metal capping layer  216  over and/or on a metal gate structure  212 . In some implementations, the opening  702  is formed directly to the metal gate structure  212 . As shown in  FIG.  7 C , the opening  702  includes a bottom surface  704  (which corresponds to the metal capping layer  216  or the metal gate structure  212 ) and sidewalls  706  (which correspond to the ESL  208 , the dielectric layer  210 , and the dielectric capping layer  218 ). 
     In some implementations, a pattern in a photoresist layer is used to etch the dielectric layer  210 , the ESL  208 , and the dielectric capping layer  218  to form the opening  702 . In these implementations, the deposition tool  102  forms the photoresist layer on the dielectric layer  210 . The exposure tool  104  exposes the photoresist layer to a radiation source to pattern the photoresist layer. The developer tool  106  develops and removes portions of the photoresist layer to expose the pattern. The etch tool  108  etches the dielectric layer  210 , the ESL  208 , and/or the dielectric capping layer  218  based on the pattern to form the opening  702 . In some implementations, the etch operation includes a plasma etch technique, a wet chemical etch technique, and/or another type of etch technique. In some implementations, a photoresist removal tool removes the remaining portions of the photoresist layer (e.g., using a chemical stripper, plasma ashing, and/or another technique). In some implementations, a hard mask layer is used as an alternative technique for etching the opening  702  based on a pattern. 
     As shown in  FIG.  7 D , a first portion of the opening  702  is filled with a conductive material (or a conductive material composition) to form the first part  224   a  of the gate interconnect structure  224 . In particular, the first part  224   a  is deposited over the conductive structure (e.g., the metal capping layer  216  or the metal cate structure  212 ) in the opening  702 . In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the first part  224   a  of the gate interconnect structure  224  in the first portion of the opening  702 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the first part  224   a  of the gate interconnect structure  224  in the first portion of the opening  702 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  702  to promote adhesion of the first part  224   a  to the sidewalls  706 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the first part  224   a  over the seed layer. A top surface  708  of the first part  224   a  of the gate interconnect structure  224  is convex (e.g., curved away from a bottom surface of the first part  224   a ) after performing the deposition operation. 
     As further shown in  FIG.  7 D , defects  710  may result in the first part  224   a  of the gate interconnect structure  224  from the formation of the first part  224   a . The defects  710  may include, for example, sidewall voids  710   a  that form from embedded defects  710   b  aggregating at the sidewalls of the first part  224   a . The sidewall voids  710   a  may continue to aggregate and in some cases may result in discontinuities or other types of defects in the first part  224   a.    
     As shown in  FIG.  7 E , an annealing operation is subsequently performed on the semiconductor device  200  after the first part  224   a  of the gate interconnect structure  224  is formed. The annealing tool  114  may perform the annealing operation to remove the defects  710  from the first part  224   a  of the gate interconnect structure  224  prior to the opening  702  being fully filled the gate interconnect structure  224 . In this way, the effectiveness of the annealing operation to remove the defects  710  is increased relative to performing the annealing operation to remove the defects  710  when the opening  702  is fully filled in the gate interconnect structure  224 . As further shown in  FIG.  7 E , the top surface  708  of the first part  224   a  of the gate interconnect structure  224  is convex (e.g., curved away from a bottom surface of the first part  224   a ) after performing the annealing operation. 
     In some implementations, the annealing operation is performed using a combination of gases including nitrogen (N2), helium (He), and argon (Ar), the annealing operation is performed in a temperature range of approximately 200 degrees Celsius to approximately 450 degrees Celsius (e.g., facilitate and promote defect migration and removal in the first part  224   a  while minimizing damage to other areas or structures of the semiconductor device  200 ), and the annealing operation is performed at a vacuum pressure range of approximately 0.5 Tor to approximately 10 Tor (e.g. facilitate and promote defect migration and removal in the first part  224   a  while minimizing other material migrations in the semiconductor device  200  and minimizing damage to other areas or structures of the semiconductor device  200 ). In some implementations, the annealing operation is performed using a gas including hydrogen (H2), a temperature range of approximately 160 degrees Celsius to approximately 450 degrees Celsius (e.g., facilitate and promote defect migration and removal in the first part  224   a  while minimizing damage to other areas or structures of the semiconductor device  200 ), and a vacuum pressure range of approximately 0.5 Tor to approximately 10 Tor (e.g. facilitate and promote defect migration and removal in the first part  224   a  while minimizing other material migrations in the semiconductor device  200  and minimizing damage to other areas or structures of the semiconductor device  200 ). However, other processing parameters such as the gas, the temperature, and/or the vacuum pressure, among other examples, are within the scope of the present disclosure. 
     As shown in  FIG.  7 F , the remaining portion of the opening  702  is filled with a conductive material (or a conductive material composition) to form the second part  224   b  of the gate interconnect structure  224  in the opening  702 . In particular, the second part  224   b  is deposited over the first part  224   a  in the opening  702 . In some implementations, the conductive material (or the conductive material composition) of the second part  224   b  is the same conductive material (or the same conductive material composition) as the conductive material (or the conductive material composition) of the first part  224   a  of the gate interconnect structure  224 . In some implementations, the conductive material (or the conductive material composition) of the second part  224   b  is different from the conductive material (or the conductive material composition) of the first part  224   a  of the gate interconnect structure  224 . 
     In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the second part  224   b  of the gate interconnect structure  224  in the remaining portion of the opening  702 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the second part  224   b  of the gate interconnect structure  224  in the remaining portion of the opening  702 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  702  to promote adhesion of the second part  224   b  to the sidewalls  706 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the second part  224   b  over the seed layer. 
     As further shown in  FIG.  7 F , the opening  702  may be overfilled to ensure complete filling of the opening  702  with the gate interconnect structure  224 . In some implementations, another annealing operation is performed for the semiconductor device  200  after forming the second part  224   b  in the opening  702 . In this way, defects in the second part  224   b  may be removed after forming the second part  224   b . As shown in  FIG.  7 G , a CMP operation is performed to planarize the gate interconnect structure  224 . 
     As indicated above,  FIGS.  7 A- 7 G  are provided as examples. Other examples may differ from what is described with regard to  FIG.  7 A- 7 G . 
       FIGS.  8 A- 8 F  are diagrams of an example implementation  800  described herein. The example implementation  800  includes another example of forming a two-part interconnect structure such as the gate interconnect structure  224  including the first part  224   a  and the second part  224   b  included in the semiconductor device  200  illustrated in  FIG.  2    and/or elsewhere herein. Turning to  FIG.  8 A , one or more operations may be performed to form the fin structure  204 , the metal gate structures  212 , the metal capping layers  216 , the dielectric capping layers  218 , the dielectric layer  206 , and/or the metal source/drain contacts  222 . Moreover, one or more operations described in connection with  FIGS.  7 A- 7 G  may be performed to form an opening (or recess)  802  above the metal gate structure  212 . As shown in  FIG.  8 A , the opening  802  includes a bottom surface  804  and sidewalls  806 . 
     As shown in  FIG.  8 B , the opening  802  (e.g., approximately the entire opening  802 ) is filled with a conductive material (or a conductive material composition) to form a sacrificial structure  808  for the gate interconnect structure  224  in the opening  802 . In particular, the sacrificial structure  808  is deposited over the conductive structure (e.g., the metal capping layer  216  or the metal cate structure  212 ) in the opening  802 . In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the sacrificial structure  808  in the opening  802 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the sacrificial structure  808  in the opening  802 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  802  to promote adhesion between the sacrificial structure  808  and the sidewalls  806  of the opening  802 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the sacrificial structure  808  in the opening  802  over the seed layer. 
     The sacrificial structure  808  includes a layer of conductive material that is to be etched back in a subsequent etching operation to form the first part  224   a  of the gate interconnect structure  224  as opposed to the partial filling technique for the first part  224   a  described above in connection with  FIGS.  7 A- 7 G . This enables non-selective materials and/or deposition techniques to be used to form the sacrificial structure  808 , as the sacrificial structure  808  is to be etched back in a subsequent etching operation. 
     As further shown in  FIG.  8 B , defects  810  may result in the sacrificial structure  808  from the formation of the sacrificial structure  808 . The defects  810  may include, for example, sidewall voids  810   a  that form from embedded defects  810   b  aggregating at the sidewalls of the sacrificial structure  808 . The sidewall voids  810   a  may continue to aggregate and in some cases may result in discontinuities or other types of defects in the sacrificial structure  808 . 
     As shown in  FIG.  8 C , an etching operation (referred to as an etch back operation) is performed to remove a portion of the sacrificial structure  808  from the opening  802 . For example, the etch tool  108  may perform the etching operation to remove the portion of the sacrificial structure  808  from the opening  802 . The remaining portion of the sacrificial structure  808  in the opening  802  becomes the first part  224   a  of the gate interconnect structure  224 . As further shown in  FIG.  8 C , a top surface  812  of the first part  224   a  of the gate interconnect structure  224  is concave (e.g., curved toward the bottom of the first part  224   a ) after the etching operation. 
     As shown in  FIG.  8 D , an annealing operation is performed on the semiconductor device  200  after the etching operation to form the first part  224   a  of the gate interconnect structure  224 . The annealing tool  114  may perform the annealing operation to remove the defects  810  from the first part  224   a  of the gate interconnect structure  224  prior to the opening  802  being fully filled the gate interconnect structure  224 . In this way, the effectiveness of the annealing operation to remove the defects  810  is increased relative to performing the annealing operation to remove the defects  810  when the opening  802  is fully filled in the gate interconnect structure  224  (or the sacrificial structure  808 ). As further shown in  FIG.  8 D , the top surface  812  of the first part  224   a  of the gate interconnect structure  224  is convex (e.g., curved away from the bottom of the first part  224   a ) after performing the annealing operation. The annealing operation may be performed using one or more (or various combinations) of the annealing operation parameters described above in connection with  FIGS.  7 A- 7 G . 
     As shown in  FIGS.  8 E and  8 F  respectively, the remaining portion of the opening  802  is filled with a conductive material (or a conductive material composition) to form the second part  224   b  of the gate interconnect structure  224  in the opening  802  and a CMP operation is performed to planarize the gate interconnect structure  224 . In some implementations, another annealing operation is performed for the semiconductor device  200  after forming the second part  224   b  in the opening  802 . In this way, defects in the second part  224   b  may be removed after forming the second part  224   b.    
     As indicated above,  FIGS.  8 A- 8 F  are provided as examples. Other examples may differ from what is described with regard to  FIG.  8 A- 8 F . 
       FIGS.  9 A- 9 F  are diagrams of an example implementation  900  described herein. The example implementation  900  includes an example of forming a two-part interconnect structure such as the source/drain interconnect structure  226  including the first part  226   a  and the second part  226   b  included in the semiconductor device  200  illustrated in  FIG.  2    and/or elsewhere herein. Turning to  FIG.  9 A , one or more operations may be performed to form the fin structure  204 , the metal gate structures  212 , the metal capping layers  216 , the dielectric capping layers  218 , the dielectric layer  206 , and/or the metal source/drain contacts  222 . Moreover, one or more operations described in connection with  FIGS.  7 A- 7 G  and/or  FIGS.  8 A- 8 F  may be performed to form the ESL  208 , the dielectric layer  210 , and the gate interconnect structure  224  including the first part  224   a  and the second part  224   b.    
     As further shown in  FIG.  9 A , a dielectric recapping layer  902  is formed over and/or on the dielectric layer  210  and over and/or on the gate interconnect structure  224 . The dielectric recapping layer  902  includes a layer of dielectric material that is used to protect the dielectric layer  210  and the gate interconnect structure  224  during the subsequent process and/or operations to form the source/drain interconnect structure  226 . In some implementations, the deposition tool  102  deposits the dielectric recapping layer  902  by a PVD operation, a CVD operation, or another type of deposition operation. 
     As shown in  FIG.  9 B , an opening (or a recess)  904  is formed in and through the dielectric recapping layer  902 , in and through the dielectric layer  210  and in and though the ESL  208 . In particular, the opening  904  is formed from the dielectric recapping layer  902  to a metal source/drain contact  222  (e.g., a conductive layer). As shown in  FIG.  9 B , the opening  904  includes a bottom surface  906  (which corresponds to the metal source/drain contact  222 ) and sidewalls  908  (which correspond to the dielectric layer  210  and the ESL  208 ). 
     In some implementations, a pattern in a photoresist layer is used to etch the dielectric layer  210 , the ESL  208 , and the dielectric recapping layer  902  to form the opening  904 . In these implementations, the deposition tool  102  forms the photoresist layer on the dielectric layer  210 . The exposure tool  104  exposes the photoresist layer to a radiation source to pattern the photoresist layer. The developer tool  106  develops and removes portions of the photoresist layer to expose the pattern. The etch tool  108  etches the dielectric layer  210 , the ESL  208 , and/or the dielectric recapping layer  902  based on the pattern to form the opening  904 . In some implementations, the etch operation includes a plasma etch technique, a wet chemical etch technique, and/or another type of etch technique. In some implementations, a photoresist removal tool removes the remaining portions of the photoresist layer (e.g., using a chemical stripper, plasma ashing, and/or another technique). In some implementations, a hard mask layer is used as an alternative technique for etching the opening  904  based on a pattern. 
     As shown in  FIG.  9 C , a first portion of the opening  904  is filled with a conductive material (or a conductive material composition) to form the first part  226   a  of the source/drain interconnect structure  226 . In particular, the first part  226   a  is deposited over the conductive structure (e.g., the metal source/drain contact  222 ) in the opening  904 . In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the first part  226   a  of the source/drain interconnect structure  226  in the first portion of the opening  904 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the first part  226   a  of the source/drain interconnect structure  226  in the first portion of the opening  904 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  904  to promote adhesion of the first part  226   a  to the sidewalls  908 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the first part  226   a  over the seed layer. A top surface  910  of the first part  226   a  of the source/drain interconnect structure  226  is convex (e.g., curved away from a bottom surface of the first part  226   a ) after performing the deposition operation. 
     As further shown in  FIG.  9 C , defects  912  may result in the first part  226   a  of the source/drain interconnect structure  226  from the formation of the first part  226   a . The defects  912  may include, for example, sidewall voids  912   a  that form from embedded defects  912   b  aggregating at the sidewalls of the first part  226   a . The sidewall voids  912   a  may continue to aggregate and in some cases may result in discontinuities or other types of defects in the first part  226   a.    
     As shown in  FIG.  9 D , an annealing operation is subsequently performed on the semiconductor device  200  after the first part  226   a  of the source/drain interconnect structure  226  is formed. The annealing tool  114  may perform the annealing operation to remove the defects  912  from the first part  226   a  of the source/drain interconnect structure  226  prior to the opening  904  being fully filled the source/drain interconnect structure  226 . In this way, the effectiveness of the annealing operation to remove the defects  912  is increased relative to performing the annealing operation to remove the defects  912  when the opening  904  is fully filled in the source/drain interconnect structure  226 . As further shown in  FIG.  9 D , a top surface  910  of the first part  224   a  of the gate interconnect structure  224  is convex (or curved away from a bottom of the first part  226   a ) after performing the annealing operation. The annealing operation may be performed using one or more (or various combinations) of the annealing operation parameters described above in connection with  FIGS.  7 A- 7 G . 
     As shown in  FIG.  9 E , the remaining portion of the opening  904  is filled with a conductive material (or a conductive material composition) to form the second part  226   b  of the source/drain interconnect structure  226  in the opening  904 . In particular, the second part  226   b  is deposited over the first part  226   a  in the opening  702 . In some implementations, the conductive material (or the conductive material composition) of the second part  226   b  is the same conductive material (or the same conductive material composition) as the conductive material (or the conductive material composition) of the first part  226   a  of the source/drain interconnect structure  226 . In some implementations, the conductive material (or the conductive material composition) of the second part  226   b  is different from the conductive material (or the conductive material composition) of the first part  226   a  of the source/drain interconnect structure  226 . 
     In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the second part  226   b  of the source/drain interconnect structure  226  in the remaining portion of the opening  904 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the second part  226   b  of the source/drain interconnect structure  226  in the remaining portion of the opening  904 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  904  to promote adhesion of the second part  226   b  to the sidewalls  908 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the second part  226   b  over the seed layer. 
     As further shown in  FIG.  9 E , the opening  904  may be overfilled to ensure complete filling of the opening  904  with the source/drain interconnect structure  226 . In some implementations, another annealing operation is performed for the semiconductor device  200  after forming the second part  226   b  in the opening  904 . In this way, defects in the second part  226   b  may be removed after forming the second part  226   b .As shown in  FIG.  9 F , a CMP operation is performed to planarize the source/drain interconnect structure  226  and to remove the remaining portions of the dielectric recapping layer  902 . 
     As indicated above,  FIGS.  9 A- 9 F  are provided as examples. Other examples may differ from what is described with regard to  FIG.  9 A- 9 F . For example, while  FIGS.  9 A- 9 F  show the source/drain interconnect structure  226  being formed subsequent to formation of the gate interconnect structure  224  using the dielectric recapping layer  902 , in other implementations, the gate interconnect structure  224  may be formed subsequent to formation of the source/drain interconnect structure  226  using the dielectric recapping layer  902 . 
       FIGS.  10 A- 10 F  are diagrams of an example implementation  1000  described herein. The example implementation  1000  includes another example of forming a two-part interconnect structure such as the source/drain interconnect structure  226  including the first part  226   a  and the second part  226   b  included in the semiconductor device  200  illustrated in  FIG.  2    and/or elsewhere herein. Turning  FIG.  10 A , one or more operations may be performed to form the fin structure  204 , the metal gate structures  212 , the metal capping layers  216 , the dielectric capping layers  218 , the dielectric layer  206 , and/or the metal source/drain contacts  222 . Moreover, one or more operations described in connection with  FIGS.  7 A- 7 G  and/or  FIGS.  8 A- 8 F  may be performed to form the ESL  208 , the dielectric layer  210 , and the gate interconnect structure  224  including the first part  224   a  and the second part  224   b.    
     As further shown in  FIG.  10 A , a dielectric recapping layer  1002  is formed over and/or on the dielectric layer  210  and over and/or on the gate interconnect structure  224 , and an opening (or a recess)  1004  is formed from dielectric recapping layer  1002  to a metal source/drain contact  222  (e.g., a conductive layer). In some implementations, the dielectric recapping layer  1002  and the opening  1004  are formed using the techniques described above in connection with  FIGS.  9 A- 9 F . The opening  1004  includes a bottom surface  1006  (which corresponds to the metal source/drain contact  222 ) and sidewalls  1008  (which correspond to the dielectric layer  210  and the ESL  208 ). 
     As shown in  FIG.  10 B , the opening  1004  (e.g., approximately the entire opening  1004 ) is filled with a conductive material (or a conductive material composition) to form a sacrificial structure  1010  for the source/drain interconnect structure  226  in the opening  1004 . In particular, the sacrificial structure  1010  is deposited over the conductive structure (e.g., the metal source/drain contact  222 ) in the opening  1004 . In some implementations, the deposition tool  102  performs a PVD operation, a CVD operation, or another type of deposition operation to form the sacrificial structure  1010  in the opening  1004 . In some implementations, the plating tool  112  performs a plating operation such as an electroplating operation to form the sacrificial structure  1010  in the opening  1004 . In some implementations, the deposition tool  102  performs a deposition operation to deposit a seed layer in the opening  1004  to promote adhesion between the sacrificial structure  1010  and the sidewalls  1008  of the opening  1004 , and the deposition tool  102  performs another deposition operation (or the plating tool  112 ) performs a plating operation to fill in the remaining portion of the sacrificial structure  1010  in the opening  1004  over the seed layer. 
     As further shown in  FIG.  10 B , defects  1012  may result in the sacrificial structure  1010  from the formation of the sacrificial structure  1010 . The defects  1012  may include, for example, sidewall voids  1012   a  that form from embedded defects  1012   b  aggregating at the sidewalls of the sacrificial structure  1010 . The sidewall voids  1012   a  may continue to aggregate and in some cases may result in discontinuities or other types of defects in the sacrificial structure  1010 . 
     As shown in  FIG.  10 C , an etching operation (referred to as an etch back operation) is performed to remove a portion of the sacrificial structure  1010  from the opening  1004 . For example, the etch tool  108  may perform the etching operation to remove the portion of the sacrificial structure  1010  from the opening  1004 . The remaining portion of the sacrificial structure  1010  in the opening  1004  becomes the first part  226   a  of the source/drain interconnect structure  226 . As further shown in  FIG.  10 C , a top surface  1014  of the first part  226   a  of the source/drain interconnect structure  226  is concave (e.g., curved toward the bottom of the first part  226   a ) after the etching operation. 
     As shown in  FIG.  10 D , an annealing operation is performed on the semiconductor device  200  after the etching operation to form the first part  226   a  of the source/drain interconnect structure  226 . The annealing tool  114  may perform the annealing operation to remove the defects  1012  from the first part  226   a  of the source/drain interconnect structure  226  prior to the opening  1004  being fully filled the source/drain interconnect structure  226 . In this way, the effectiveness of the annealing operation to remove the defects  1012  is increased relative to performing the annealing operation to remove the defects  1012  when the opening  1004  is fully filled in the source/drain interconnect structure  226  (or the sacrificial structure  1010 ). As further shown in  FIG.  10 D , the top surface  1014  of the first part  226   a  of the source/drain interconnect structure  226  is convex (e.g., curved away from the bottom of the first part  226   a ) after performing the annealing operation. The annealing operation may be performed using one or more (or various combinations) of the annealing operation parameters described above in connection with  FIGS.  7 A- 7 G . 
     As shown in  FIGS.  10 E and  10 F  respectively, the remaining portion of the opening  1004  is filled with a conductive material (or a conductive material composition) to form the second part  226   b  of the source/drain interconnect structure  226  in the opening  1004  and a CMP operation is performed to planarize the source/drain interconnect structure  226 . In some implementations, another annealing operation is performed for the semiconductor device  200  after forming the second part  226   b  in the opening  1004 . In this way, defects in the second part  226   b  may be removed after forming the second part  226   b.    
     As indicated above,  FIGS.  10 A- 10 F  are provided as examples. Other examples may differ from what is described with regard to  FIG.  10 A- 10 F . For example, while  FIGS.  10 A- 10 F  show the source/drain interconnect structure  226  being formed subsequent to formation of the gate interconnect structure  224  using the dielectric recapping layer  1002 , in other implementations, the gate interconnect structure  224  may be formed subsequent to formation of the source/drain interconnect structure  226  using the dielectric recapping layer  1002 . 
       FIG.  11    is a diagram of another example implementation  1100  of a portion of the semiconductor device  200  of  FIG.  2    described herein. In particular,  FIG.  11    illustrates a three-dimensional illustration of a portion of the semiconductor device  200 .  FIG.  11    illustrates the three-dimensional aspects of the device substrate  202 , the fin structure  204 , the dielectric layer  206 , the ESL  208 , the dielectric layer  210 , the metal gate structure  212 , the sidewall spacers  214 , the metal capping layer  216 , the source/drain regions  220 , the metal source/drain contacts  222 , a two-part gate interconnect structure  224  (e.g., including a first part  224   a  and a second part  224   b ), and a source/drain interconnect structure  226  (which may include a two-part source/drain interconnect structure  226  including a first part  226   a  and a second part  226   b , or a single-part source/drain interconnect structure  226 ). 
     As further shown in  FIG.  11   , the semiconductor device  200  may include a plurality of STI regions  1102  between the fin structures  204  and below the source/drain regions  220 . In other words, the source/drain regions  220  are located on top of the fin structures  204  and above the STI regions  1102 . Silicide layers  1104  are further included between the source/drain regions  220  and the associated metal source/drain contacts  222 . CESLs  1106  are included between the gate stacks of the semiconductor device  200  and the metal source/drain contacts  222 . 
     As indicated above,  FIG.  11    is provided as an example. Other examples may differ from what is described with regard to  FIG.  11   . 
       FIGS.  12 A- 12 D  are diagrams of other example implementations of a portion of the semiconductor device  200  of  FIG.  2    described herein.  FIGS.  12 A- 12 C  illustrate various combinations of gate interconnect structure types and source/drain interconnect structure types, including two-part gate interconnect structures, single-part gate interconnect structures, two-part source/drain interconnect structures, and/or single-part source/drain interconnect structures. 
     As shown in  FIG.  12 A , an example implementation  1210  of a portion of the semiconductor device  200  includes similar structures as illustrated in  FIG.  2   . However, the portion of the semiconductor device  200  illustrated in the example implementation  1210  of  FIG.  12 A  includes a single-part source/drain interconnect structure  226  (e.g., a source/drain interconnect structure that is formed or filled by a single deposition operation and a single annealing operation) in combination with a two-part gate interconnect structure  224  that includes the first part  224   a  and the second part  224   b . The combination of the two-part gate interconnect structure  224  and the single-part source/drain interconnect structure  226  enables the process for forming the single-part source/drain interconnect structure  226  to be simplified while enabling increased defect removal and increased interconnect performance for the two-part gate interconnect structure  224 . 
     As shown in  FIG.  12 B , an example implementation  1220  of a portion of the semiconductor device  200  includes similar structures as illustrated in  FIG.  2   . However, the portion of the semiconductor device  200  illustrated in the example implementation  1220  of  FIG.  12 B  includes a single-part gate interconnect structure  224  (e.g., a gate interconnect structure that is formed or filled by a single deposition operation and a single annealing operation) in combination with a two-part source/drain interconnect structure  226  that includes the first part  226   a  and the second part  226   b .The combination of the single-part gate interconnect structure  224  and the two-part source/drain interconnect structure  226  enables the process for forming the single-part gate interconnect structure  224  to be simplified while enabling increased defect removal and increased interconnect performance for the two-part source/drain interconnect structure  226 . 
     As shown in  FIG.  12 C , an example implementation  1230  of a portion of the semiconductor device  200  includes similar structures as illustrated in  FIG.  2   . However, in the example implementation  1230 , the semiconductor device  200  further includes a metal gate contact  1232 . The metal capping layer  216  and/or the dielectric capping layer  218  may be omitted from the semiconductor device  200  in the example implementation  1230 , and the sidewall spacers  214  may approximately extend from fin structure  204  to another ESL  1234 . Similarly, the metal gate structure  212  may approximately extend from fin structure  204  to another ESL  1234 . Another dielectric layer  1236  (e.g., an ILD 1  layer) may be included between the dielectric layer  206  (e.g., the ILDO layer) and the dielectric layer  210  (e.g., the ILD 2  layer). The metal source/drain contacts  222  may extend from the source/drain regions  220  to approximately the top surface of the dielectric layer  1236 , similar to the metal gate contact  1232  (which may be referred to as an MP). In this way, the height of the top surface of the metal gate contact  1232  and the height of the top surface of the metal source/drain contacts  222  are approximately the same height. Accordingly, the vertical position of the top surface of the metal gate contact  1232  in the semiconductor device  200  and the vertical position of the top surface of the metal source/drain contacts  222  are approximately equal. 
     As further shown in  FIG.  12 C , the gate interconnect structure  224  is electrically and/or physically connected to the metal gate contact  1232 . The source/drain interconnect structure  226  is electrically and/or physically connected to a metal source/drain contact  222 . The gate interconnect structure  224  and the source/drain interconnect structure  226  may be located in and/or through the ESL  208  and in and/or through the dielectric layer  210 . In this way, the height of the gate interconnect structure  224  and the height of the source/drain interconnect structure  226  are approximately the same height. 
     As further shown in  FIG.  12 C , the gate interconnect structure  224  and/or the source/drain interconnect structure  226  include a two-part interconnect structure. For example, the gate interconnect structure  224  may include the first part  224   a  that is electrically and/or physically connected to the metal gate contact  1232 , and the second part  224   b  over and/or on the first part  224   a . The first part  224   a  may extend through the ESL  208  and a portion of the dielectric layer  210 , and the second part  224   b  may extend through another portion of the dielectric layer  210 . The first part  224   a  and the second part  224   b  illustrated in  FIG.  12 C  may be formed by similar operations and/or techniques described herein, for example, in connection with  FIGS.  7 A- 7 G and/or  8 A- 8 F  remove defects and/or minimize defect formation in the gate interconnect structure  224 . 
     As another example, the source/drain interconnect structure  226  may include the first part  226   a  that is electrically and/or physically connected to a metal source/drain contact  222 , and the second part  226   b  over and/or on the first part  226   a . The first part  226   a  may extend through the ESL  208  and a portion of the dielectric layer  210 , and the second part  226   b  may extend through another portion of the dielectric layer  210 . The first part  226   a  and the second part  226   b  illustrated in  FIG.  12 C  may be formed by similar operations and/or techniques described herein, for example, in connection with  FIGS.  9 A- 9 F and/or  10 A- 10 F  remove defects and/or minimize defect formation in the source/drain interconnect structure  226 . 
     In the example implementation  1230  illustrated in  FIG.  12 C , the bottom width of the first part  224   a  of the gate interconnect structure  224  may be included in a range of approximately 8 millimeters to approximately 18 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the bottom width of the first part  226   a  of the source/drain interconnect structure  226  may be included in a range of approximately 8 millimeters to approximately 18 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the bottom width of the second part  224   b  of the gate interconnect structure  224  may be included in a range of approximately 10 millimeters to approximately 20 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the bottom width of the second part  226   b  of the source/drain interconnect structure  226  may be included in a range of approximately 10 millimeters to approximately 20 millimeters. 
     In the example implementation  1230  illustrated in  FIG.  12 C , the height or thickness of the first part  224   a  of the gate interconnect structure  224  may be included in a range of approximately 5 millimeters to approximately 20 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the height or thickness of the second part  224   b  of the gate interconnect structure  224  may be included in a range of approximately 5 millimeters to approximately 40 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the height or thickness of the first part  226   a  of the source/drain interconnect structure  226  may be included in a range of approximately 5 millimeters to approximately 20 millimeters. In the example implementation  1230  illustrated in  FIG.  12 C , the height or thickness of the second part  226   b  of the source/drain interconnect structure  226  may be included in a range of approximately 5 millimeters to approximately 40 millimeters. 
     As shown in  FIG.  12 D , an example implementation  1240  of a portion of the semiconductor device  200  includes similar structures as illustrated in  FIG.  12 D . However, in the example implementation  1240 , the semiconductor device  200  further includes a metal source/drain contact  222  includes a two-part contact structure. The two-part contact structure includes a first part  222   a  that is electrically and/or physically connected to source/drain region  220 , and the second part  222   b  over and/or on the first part  222   a . The first part  222   a  and the second part  222   b  illustrated in  FIG.  12 C  may be formed by similar operations and/or techniques described herein, for example, in connection with  FIGS.  7 A- 7 G and/or  8 A- 8 F  remove defects and/or minimize defect formation in the metal source/drain contact  222 . 
     The first part  222   a  may extend through at least a portion of the dielectric layer  206 , through at least a portion of the ESL  208 , and/or through at least a portion of the dielectric layer  1236 , and the second part  222   b  may extend through at least a portion of the dielectric layer  206 , through at least a portion of the ESL  208 , and/or through at least a portion of the dielectric layer  1236 . An interface between the first part  222   a  and the second part  222   b  may be included between a top surface and a bottom surfaces of the dielectric layer  206 , between a top surface and a bottom surface of the ESL  208 , or between a top surface and a bottom surface of the dielectric layer  1236 . 
     In some implementations, a two-part metal gate contact  1232  may be included in a similar manner as the two-part metal source/drain contact. 
     As indicated above,  FIGS.  12 A- 12 D  are provided as examples. Other examples may differ from what is described with regard to  FIG.  12 A- 12 D . Moreover one or more implementations described in connection with  FIGS.  12 A- 12 D  may be combined with one or more other implementations described in connection with  FIGS.  12 A- 12 D  and/or described elsewhere herein. 
       FIG.  13    is a diagram of example components of a device  1300 . In some implementations, one or more of the semiconductor processing tools  102 - 114  and/or the wafer/die transport tool  116  may include one or more devices  1300  and/or one or more components of device  1300 . As shown in  FIG.  13   , device  1300  may include a bus  1310 , a processor  1320 , a memory  1330 , an input component  1340 , an output component  1350 , and a communication component  1360 . 
     Bus  1310  includes one or more components that enable wired and/or wireless communication among the components of device  1300 . Bus  1310  may couple together two or more components of  FIG.  13   , such as via operative coupling, communicative coupling, electronic coupling, and/or electric coupling. Processor  1320  includes a central processing unit, a graphics processing unit, a microprocessor, a controller, a microcontroller, a digital signal processor, a field-programmable gate array, an application-specific integrated circuit, and/or another type of processing component. Processor  1320  is implemented in hardware, firmware, or a combination of hardware and software. In some implementations, processor  1320  includes one or more processors capable of being programmed to perform one or more operations or processes described elsewhere herein. 
     Memory  1330  includes volatile and/or nonvolatile memory. For example, memory  1330  may include random access memory (RAM), read only memory (ROM), a hard disk drive, and/or another type of memory (e.g., a flash memory, a magnetic memory, and/or an optical memory). Memory  1330  may include internal memory (e.g., RAM, ROM, or a hard disk drive) and/or removable memory (e.g., removable via a universal serial bus connection). Memory  1330  may be a non-transitory computer-readable medium. Memory  1330  stores information, instructions, and/or software (e.g., one or more software applications) related to the operation of device  1300 . In some implementations, memory  1330  includes one or more memories that are coupled to one or more processors (e.g., processor  1320 ), such as via bus  1310 . 
     Input component  1340  enables device  1300  to receive input, such as user input and/or sensed input. For example, input component  1340  may include a touch screen, a keyboard, a keypad, a mouse, a button, a microphone, a switch, a sensor, a global positioning system sensor, an accelerometer, a gyroscope, and/or an actuator. Output component  1350  enables device  1300  to provide output, such as via a display, a speaker, and/or a light-emitting diode. Communication component  1360  enables device  1300  to communicate with other devices via a wired connection and/or a wireless connection. For example, communication component  1360  may include a receiver, a transmitter, a transceiver, a modem, a network interface card, and/or an antenna. 
     Device  1300  may perform one or more operations or processes described herein. For example, a non-transitory computer-readable medium (e.g., memory  1330 ) may store a set of instructions (e.g., one or more instructions or code) for execution by processor  1320 . Processor  1320  may execute the set of instructions to perform one or more operations or processes described herein. In some implementations, execution of the set of instructions, by one or more processors  1320 , causes the one or more processors  1320  and/or the device  1300  to perform one or more operations or processes described herein. In some implementations, hardwired circuitry may be used instead of or in combination with the instructions to perform one or more operations or processes described herein. Additionally, or alternatively, processor  1320  may be configured to perform one or more operations or processes described herein. Thus, implementations described herein are not limited to any specific combination of hardware circuitry and software. 
     The number and arrangement of components shown in  FIG.  13    are provided as an example. Device  1300  may include additional components, fewer components, different components, or differently arranged components than those shown in  FIG.  13   . Additionally, or alternatively, a set of components (e.g., one or more components) of device  1300  may perform one or more functions described as being performed by another set of components of device  1300 . 
       FIG.  14    is a flowchart of an example process  1400  related to forming a semiconductor interconnect structure described herein. In some implementations, one or more process blocks of  FIG.  14    may be performed by one or more semiconductor processing tools (e.g., one or more of the semiconductor processing tools  102 - 114 ). Additionally, or alternatively, one or more process blocks of  FIG.  14    may be performed by one or more components of device  1300 , such as processor  1320 , memory  1330 , input component  1340 , output component  1350 , and/or communication component  1360 . 
     As shown in  FIG.  14   , process  1400  may include forming an opening through a first dielectric layer, through an etch stop layer, and to a conductive structure in a second dielectric layer of a semiconductor device (block  1410 ). For example, the one or more semiconductor processing tools  102 - 114  may form an opening (e.g., the opening  702 ,  904 ) through a first dielectric layer (e.g., the dielectric layer  210 ), through an etch stop layer (e.g., the ESL  208 ), and to a conductive structure (e.g., the metal capping layer  216 , the metal source/drain contact  222 ) in a second dielectric layer (e.g., the dielectric layer  206 ) of the semiconductor device  200 , as described herein. 
     As further shown in  FIG.  14   , process  1400  may include filling a first portion of the opening with a first part of an interconnect structure over the conductive structure (block  1420 ). For example, the one or more semiconductor processing tools  102 - 114  may fill a first portion of the opening with a first part (e.g., the first part  224   a , the first part  226   a ) of an interconnect structure (e.g., the gate interconnect structure  224 , the source/drain interconnect structure  226 ) over the conductive structure, as described herein. 
     As further shown in  FIG.  14   , process  1400  may include performing an annealing operation on the semiconductor device to remove defects from the first part of the interconnect structure (block  1430 ). For example, the one or more semiconductor processing tools  102 - 114  may perform an annealing operation on the semiconductor device  200  to remove defects (e.g., defects  710 , defects  912 ) from the first part of the interconnect structure, as described above. In some implementations, a top surface (e.g., the top surface  708 , the top surfaces  910 ) of the first part of the interconnect structure is convex after performing the annealing operation. 
     As further shown in  FIG.  14   , process  1400  may include filling a remaining portion of the opening with a second part of the interconnect structure after performing the annealing operation (block  1440 ). For example, the one or more semiconductor processing tools  102 - 114  may fill a remaining portion of the opening with a second part (e.g., the second part  224   b , the second part  226   b ) of the interconnect structure after performing the annealing operation, as described above. 
     Process  1400  may include additional implementations, such as any single implementation or any combination of implementations described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first implementation, process  1400  includes performing another annealing operation on the semiconductor device  200  to remove defects from the second part of the interconnect structure, and performing a CMP operation on the second part of the interconnect structure. In a second implementation, alone or in combination with the first implementation, performing the annealing operation includes performing the annealing operation using a combination of gases including nitrogen (N 2 ), helium (He), and argon (Ar), a temperature range of approximately 200 degrees Celsius to approximately 450 degrees Celsius, and a vacuum pressure range of approximately 0.5 Tor to approximately 10 Tor. In a third implementation, alone or in combination with one or more of the first and second implementations, performing the annealing operation includes performing the annealing operation using hydrogen gas (H2), a temperature range of approximately 160 degrees Celsius to approximately 450 degrees Celsius, and a vacuum pressure range of approximately 0.5 Tor to approximately 10 Tor. 
     In a fourth implementation, alone or in combination with one or more of the first through third implementations, process  1400  includes forming a dielectric recapping layer (e.g., the dielectric recapping layer  902 , the dielectric recapping layer  1002 ) on the first dielectric layer and on the second part of the interconnect structure after filling the remaining portion of the opening with the second part of the interconnect structure, forming another opening (e.g., the opening  904 , the opening  1004 ) through the dielectric recapping layer, through the first dielectric layer, through the etch stop layer, and to another conductive structure (e.g., the metal source/drain contact  222 ) in the second dielectric layer of the semiconductor device, forming a first part (e.g., the first part  226   a ) of another interconnect structure (e.g., the source/drain interconnect structure  226 ) in the other opening, performing another annealing operation on the first part of the other interconnect structure to remove defects (e.g., the defects  912 , the defects  1012 ) from the first part of the other interconnect structure, and filling a remaining portion of the other opening with a second part (e.g., the second part  226   b ) of the other interconnect structure after performing the other annealing operation. In a fifth implementation, alone or in combination with one or more of the first through fourth implementations, a vertical position of a bottom surface of the first part of the interconnect structure is lower in the semiconductor device  200  relative to a bottom surface of the first part of the other interconnect structure. 
     Although  FIG.  14    shows example blocks of process  1400 , in some implementations, process  1400  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  14   . Additionally, or alternatively, two or more of the blocks of process  1400  may be performed in parallel. 
       FIG.  15    is a flowchart of an example process  1500  related to forming a semiconductor interconnect structure described herein. In some implementations, one or more process blocks of  FIG.  15    may be performed by one or more semiconductor processing tools (e.g., one or more of the semiconductor processing tools  102 - 114 ). Additionally, or alternatively, one or more process blocks of  FIG.  15    may be performed by one or more components of device  1300 , such as processor  1320 , memory  1330 , input component  1340 , output component  1350 , and/or communication component  1360 . 
     As shown in  FIG.  15   , process  1500  may include forming an opening through a first dielectric layer, through an etch stop layer, and to a conductive structure in a second dielectric layer of a semiconductor device (block  1510 ). For example, the one or more semiconductor processing tools  102 - 114  may form an opening (e.g., the opening  802 , the opening  1004 ) through a first dielectric layer (e.g., the dielectric layer  210 ), through an etch stop layer (e.g., the ESL  208 ), and to a conductive structure (e.g., the metal capping layer  216 , metal source/drain contact  222 ) in a second dielectric layer (e.g., the dielectric layer  206 ) of the semiconductor device  200 , as described above. 
     As further shown in  FIG.  15   , process  1500  may include filling the opening with a sacrificial structure over the conductive structure (block  1520 ). For example, the one or more semiconductor processing tools  102 - 114  may fill the opening with a sacrificial structure (e.g., the sacrificial structure  808 , the sacrificial structure  1010 ) over the conductive structure, as described above. 
     As further shown in  FIG.  15   , process  1500  may include performing an etch back operation to remove a portion of the sacrificial structure in the opening (block  1530 ). For example, the one or more semiconductor processing tools  102 - 114  may perform an etch back operation to remove a portion of the sacrificial structure in the opening, as described above. In some implementations, a remaining portion of the sacrificial structure in the opening includes a first part (e.g., the first part  224   a , the first part  226   a ) of an interconnect structure (e.g., the gate interconnect structure  224 , the source/drain interconnect structure  226 ) over the conductive structure. 
     As further shown in  FIG.  15   , process  1500  may include performing, after performing the etch back operation, an annealing operation on the semiconductor device to remove defects from the first part of the interconnect structure (block  1540 ). For example, the one or more semiconductor processing tools  102 - 114  may perform, after performing the etch back operation, an annealing operation on the semiconductor device to remove defects (e.g., the defects  810 , the defects  1012 ) from the first part of the interconnect structure, as described above. In some implementations, a top surface (e.g., the top surface  812 , the top surfaces  1014 ) of the first part of the interconnect structure is convex after performing the annealing operation. 
     As further shown in  FIG.  15   , process  1500  may include filling a remaining portion of the opening with a second part of the interconnect structure after performing the annealing operation (block  1550 ). For example, the one or more semiconductor processing tools  102 - 114  may fill a remaining portion of the opening with a second part (e.g., the second part  224   b , the second part  226   b ) of the interconnect structure after performing the annealing operation, as described above. 
     Process  1500  may include additional implementations, such as any single implementation or any combination of implementations described below and/or in connection with one or more other processes described elsewhere herein. 
     In a first implementation, the top surface of the first part of the interconnect structure is concave after performing the etch back operation and prior to performing the annealing operation. In a second implementation, alone or in combination with the first implementation, process  1500  includes performing another annealing operation on the semiconductor device  200  to remove defects from the second part of the interconnect structure, and performing a CMP operation on the second part of the interconnect structure after performing the other annealing operation. 
     In a third implementation, alone or in combination with one or more of the first and second implementations, the conductive structure includes a metal source/drain contact  222 , and a vertical position of the first part of the interconnect structure is greater than a vertical position of the metal source/drain contact  222 . In a fourth implementation, alone or in combination with one or more of the first through third implementations, process  1500  includes forming a dielectric recapping layer (e.g., the dielectric recapping layer  902 , the dielectric recapping layer  1002 ) on the first dielectric layer and on the second part of the interconnect structure after filling the remaining portion of the opening with the second part of the interconnect structure, forming another opening (e.g., the opening  904 , the opening  1004 ) through the dielectric recapping layer, through the first dielectric layer, through the etch stop layer, and to another conductive structure (e.g., the metal source/drain contact  222 ) in the second dielectric layer of the semiconductor device, forming a first part (e.g., the first part  226   a ) of another interconnect structure (e.g., the source/drain interconnect structure  226 ) in the other opening, performing another annealing operation on the first part of the other interconnect structure to remove defects (e.g., defects  912 , defects  1012 ) from the first part of the other interconnect structure, and filling a remaining portion of the other opening with a second part (e.g., the second part  226   b ) of the other interconnect structure after performing the other annealing operation. 
     Although  FIG.  15    shows example blocks of process  1500 , in some implementations, process  1500  may include additional blocks, fewer blocks, different blocks, or differently arranged blocks than those depicted in  FIG.  15   . Additionally, or alternatively, two or more of the blocks of process  1500  may be performed in parallel. 
     In this way, the two-step anneal techniques described herein include performing a first anneal operation on a first portion of the interconnect, filling the remaining portion of the interconnect, and then performing a second anneal operation on the interconnect. The two-step anneal techniques described herein enable the removal of defects in an interconnect structure, particularly for high aspect ratio interconnect structures. Accordingly, the two-step anneal techniques described herein may be used to fabricate defect free or near defect free interconnect structures in a semiconductor device. This reduces contact resistance for the interconnect structures, reduces premature device failure for the semiconductor device, increases manufacturing yield, and increases tolerance of the interconnect structures to subsequent processing operations, among other examples. 
     As described in greater detail above, some implementations described herein provide a semiconductor device. The semiconductor device includes a metal gate structure. The semiconductor device includes a gate interconnect structure, connected to the metal gate structure, including a first part orientated toward the metal gate structure and a second part on the first part. An interface between the first part and the second part is curved, and the gate interconnect structure is tapered between a top of the second part and a bottom of the first part in an approximately continuous and uniform manner. 
     As described in greater detail above, some implementations described herein provide a method. The method includes forming an opening through a first dielectric layer, through an etch stop layer, and to a conductive structure in a second dielectric layer of a semiconductor device. The method includes filling a first portion of the opening with a first part of an interconnect structure over the conductive structure. The method includes performing an annealing operation on the semiconductor device to remove defects from the first part of the interconnect structure, where a top surface of the first part of the interconnect structure is convex after performing the annealing operation. The method includes filling a remaining portion of the opening with a second part of the interconnect structure after performing the annealing operation. 
     As described in greater detail above, some implementations described herein provide a method. The method includes forming an opening through a first dielectric layer, through an etch stop layer, and to a conductive structure in a second dielectric layer of a semiconductor device. The method includes filling the opening with a sacrificial structure over the conductive structure. The method includes performing an etch back operation to remove a portion of the sacrificial structure in the opening, where a remaining portion of the sacrificial structure in the opening includes a first part of an interconnect structure over the conductive structure. The method includes performing, after performing the etch back operation, an annealing operation on the semiconductor device to remove defects from the first part of the interconnect structure, where a top surface of the first part of the interconnect structure is convex after performing the annealing operation. The method includes filling a remaining portion of the opening with a second part of the interconnect structure after performing the annealing operation. 
     The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.