Patent Document

CROSS-REFERENCE  
       [0001]     This application is related to the following commonly-assigned U.S. patent application, the entire disclosure of which is hereby incorporated herein by reference: “A Novel Dual Strained CMOS,” Attorney Docket No. 24061.175, filed Apr. 6, 2004 having Chuan-Yi Lin, Wen-Chin Lee, Sun-Jay Chang, and Shien-Yang Wu named as inventors. 
     
    
     TECHNICAL FIELD  
       [0002]     The present disclosure relates generally to microelectronic devices and methods of manufacturing, and more specifically to a microelectronic device with electrode perturbing sill.  
       BACKGROUND  
       [0003]     An integrated circuit (IC) is formed by creating one or more devices (e.g., circuit components) on a semiconductor substrate using a fabrication process. As fabrication processes and materials improve, semiconductor device geometries have continued to decrease in size since such devices were first introduced several decades ago. For example, current fabrication processes are producing devices having geometry sizes (e.g., the smallest component or line that may be created using the process) of less than 90 nm. However, the reduction in size of device geometries frequently introduces new challenges that need to be overcome.  
         [0004]     As microelectronic devices are scaled below 45 nm, the electrical efficiency and become an issue that impacts device performance. Microelectronic device performance can be significantly affected by the electron and hole mobility in semiconductor materials. For example, advanced microelectronic devices may incorporate strained silicon as the substrate. Strained silicon comprises a plurality of layers to provide a lattice mismatch of silicon atoms and other atoms such as germanium. The lattice mismatch can provide enhanced improvement of the electron and/or hole mobility of the microelectronic device, thus a reduction in the threshold voltage may be required for a field effect transistor on strained silicon. However, the plurality of layers that form the strained silicon may not provide optimal device operation for all microelectronic devices of a semiconductor product. For example, NMOS devices and PMOS devices can have differing electrical characteristics when fabricated on strained silicon. Furthermore, the stress in the gate electrode and the channel may vary amongst a plurality of CMOS devices. The differences in the electrical characteristics mandates modification of either the NMOS and/or the PMOS device in strained silicon microelectronic devices.  
         [0005]     Accordingly, what is needed in the art is a integrated circuit device and method thereof that addresses the above discussed issues. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]     Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying figures. It is emphasized 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.  
         [0007]      FIG. 1   a - b  illustrate sectional views of one embodiment of a microelectronic device constructed according to aspects of the present disclosure.  
         [0008]      FIG. 2  illustrates a perspective view of one embodiment of a microelectronic device constructed according to aspects of the present disclosure.  
         [0009]      FIG. 3  illustrates a sectional view of another embodiment of microelectronic device constructed according to aspects of the present disclosure.  
         [0010]      FIG. 4  illustrates a sectional view of one embodiment of an integrated circuit constructed according to aspects of the present disclosure.  
         [0011]      FIG. 5  illustrates a sectional view of another embodiment of an integrated circuit device constructed according to aspects of the present disclosure.  
     
    
     DETAILED DESCRIPTION  
       [0012]     The present disclosure relates generally to a microelectronic device and method for fabrication, and more specifically to a microelectronic device with electrode perturbing sill. It is understood, however, that the following disclosure provides many different embodiments or examples. 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. 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.  
         [0013]     Referring to  FIG. 1   a,  illustrated is a sectional view of one embodiment of a microelectronic device  100  in an intermediate stage of manufacture according to aspects of the present disclosure. Microelectronic device  100  includes a substrate  110 , at least one doped region(s)  120 , doped source/drain regions  130 , a partition layer  140 , an electrode insulator  145 , an electrode layer  152 , a mask  160 , and a sill  170 .  
         [0014]     The substrate  110  may include a plurality of microelectronic devices  100 , wherein one or more layers of such a gate structure, or other features contemplated by the microelectronic device  100  within the scope of the present disclosure, may be formed by immersion photolithography, maskless lithography, chemical-vapor deposition (CVD), physical-vapor deposition (PVD), plasma-enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD) and/or other process techniques. Conventional and/or future-developed lithographic, etching and other processes may be employed to define the microelectronic device  100  from the deposited layer(s). The substrate  110  may be a silicon-on-insulator (SOI) substrate, a polymer-on-silicon, and may comprise silicon, gallium arsenide, gallium nitride, strained silicon, silicon germanium, silicon carbide, carbide, diamond and/or other materials. Alternatively, the substrate  110  may comprise a fully depleted SOI substrate wherein the device active silicon thickness may range between about 200 nm and about 50 nm.  
         [0015]     The doped region(s)  120  may be formed in the substrate  110  by ion implantation (although use of a P doped substrate may negate the need for a well region). For example, the doped region(s)  120  may be formed by growing a sacrificial oxide on the substrate  110 , opening a pattern for the location of the region(s)  120 , and then using a chained-implantation procedure, as is known in the art. It is understood that the substrate  110  may have a P doped well or a combination of P and N wells. The doped region(s)  120 , while not limited to any particular dopant types or schemes, in one embodiment, the doped region(s)  120  and/or source/drain regions  130  employ boron as a p-type dopant and deuterium-boron complexes for an n-type dopant. The deuterium-boron complexes may be formed by plasma treatment of boron-doped diamond layers with a deuterium plasma.  
         [0016]     In one embodiment, the doped region(s)  120  may be formed using a high density plasma source with a carbon-to-deuterium ratio ranging between about 0.1 percent and about 5 percent in a vacuum process ambient. Boron doping may be provided by the mixing of a boron containing gas with a carbon/hydrogen gas. The boron containing gas may include B 2 H 6 , B 2 D 6  and/or other boron containing gases. The concentration of boron doping may depend upon the amount of boron containing gas that may be leaked or added into the process. The process ambient pressure may range between 0.1 mTorr and about 500 Torr. The substrate  110  may be held at a temperature ranging between 150° C. and about 1100° C. High density plasma may be produced by a microwave electron cyclotron resonance (ECR) plasma, a helicon plasma, a inductively coupled plasma and/or other high density plasma sources. For example, the ECR plasma may utilize microwave powers ranging between about 800 Watts and about 2500 Watts.  
         [0017]     As described above, the doped region(s)  120  may also be n-type deuterium-boron complex regions of the substrate  110 , which may be formed by treating the above-described boron-doped regions employing a deuterium plasma. For example, selected areas of the substrate  110  may be covered by photoresist or another type of mask such that exposed boron-doped regions may be treated with the deuterium containing plasma. The deuterium ions may provide termination of dangling bonds, thereby transmuting the p-type boron-doped regions into n-type deuterium-boron complex regions. Alternatively, deuterium may be replaced with tritium, hydrogen and/or other hydrogen containing gases. The concentration of the n-type regions may generally be controlled by a direct current (DC) or a radio frequency (RF) bias of the substrate  110 . The above-described processes may also be employed to form lightly-doped source/drain regions  130  in the substrate  110 . Of course, other conventional and/or future-developed processes may also or alternatively be employed to form the source/drain regions  130 .  
         [0018]     The partition layer  140  includes a material for providing a process end point and/or for the prevention of formation of the electrode insulator  145  For example, the partition layer  140  may include Si 3 N 4 , which prevents oxide formation where the prevention layer  140  exits. The partition layer  140  may also include SiON, SiC, and/or other materials adapted for the prevention of material formation during a subsequent process. The electrode insulator  145  or “gate dielectric” may include a SiO 2  and/or nitrided SiO 2 . Alternatively, the electrode insulator  145  material may be replaced by the high-k dielectric.  
         [0019]     The electrode layer  152  may include a stack of material layers to form the electrode  150 . The electrode  150  may provide electrical activation of at least one function of the microelectronic device  100 . In one embodiment, the electrode insulator  145  and/or the electrode layer  152  may include multiple layers such as a high-k dielectric later, a polysilicon layer, metal alloy and/or other material layers. Other materials for the electrode  150  may include Ti, Ta, Mo, Co, W, TiN, TaN, WN, MoSi, WSi, CoSi, and/or other materials. In one embodiment, the high-k layer may be formed from a variety of different materials, such as TaN, TiN, Ta 2 O 5 , HfO 2 , ZrO 2 , HFSiON, HfSi x , HfSi x N y , HfAlO 2 , Al 2 O 3 , NiSi x , or other suitable materials using ALD, CVD, PECVD, evaporation, or other methods. Generally, the high-k layer may have a thickness between approximately 2 and 80 Angstroms. With some materials, such as HfSiON, the high-k layer of the electrode layer  152  may be blanket deposited on the surface of the substrate  110 , while other materials may be selectively deposited. Alternatively, it may be desirable to blanket deposit some materials, including HfSiON, in some fabrication processes, while selectively depositing the same materials in other processes. Since the gate oxide thickness continues to decrease along with device geometries, incorporating such high-k materials may yield the higher capacitance needed to reduce the gate leakage associated with smaller device geometries.  
         [0020]     The mask  160  includes a pattern material for allowing the formation of the sill  170  at selected portions of the microelectronic device  102 . The mask  160  may comprise photo resist, Si 3 N 4 , SiON, SiO 2 , polymer, and/or other materials.  
         [0021]     The sill  170  includes a plurality of conducting and/or semiconductor materials which may provide lattice stress balancing amongst a plurality of microelectronic device(s)  100 —of an integrated circuit. The sill  170  may be formed upon and/or within the substrate  110 . For example, the sill  170  may be deposited upon the substrate  110  by CVD, PECVD, ALD, PVD, and/or other processes. The sill  170  may also be formed by ion implantation as indicated by ion implantation arrows  175 , wherein the sill  170  may be formed within an arbitrary depth of the substrate  110 . The depth of the ion implantation of sill  170  may be controlled through the impurity implant energy, which may range between about 1 KeV and about 800 KeV. The impurity concentration may range between about 1×10 13  atoms/cm 3  and about 1×10 19  atoms/cm 3 .  
         [0022]     In one embodiment, the ion implantation  175  may be performed by plasma source ion implantation (PSII), or also referred to as plasma source ion immersion. PSII may include a process wherein the electrode layer  152  may be exposed to a plasma source, while an applied bias may be applied to the substrate  110 . The processing tool to perform PSII may include a single and/or batch wafer reactor, wherein a direct current (DC) and/or radio frequency (RF) bias may be applied to the substrate(s)  110 . The PSII reactor includes a process ambient pressure that may range between 0.01 mTorr and about 1000 Torr. The substrate  110  may be held at a temperature ranging between 150° C. and about 1100° C. High density plasma may be produced by a microwave electron cyclotron resonance (ECR) plasma, a helicon plasma, a inductively coupled plasma and/or other high density plasma sources. The plasma may comprise Ar, H, N, Xe, O, As, B 2 H 6 , GeH 4 , P, and/or other sources of the impurity. For example, the helicon plasma may utilize RF powers ranging between about 200 Watts and about 2500 Watts. The applied bias may range between about ±200 V and about ±5000 V. The application of the bias to the substrate  110  in the plasma creates an extended plasma sheath substantially covering the microelectronic device  100 , wherein ions and/or electrons may be accelerated away from the plasma sheath, thereby accelerating the ions of the impurity into the electrode layer  152 , to form the sill  170 .  
         [0023]     The sill  170  may also include a monolayer of the compound. Alternatively, the sill  170  may include a plurality of different impurity layers. For example, the sill  170  may comprise a first Ge layer, a second strained SiGe layer, a layer comprising Si, SiC, and/or other materials.  
         [0024]     Of course it is understood that the location of the sill  170  may include a flat plane of the substrate  110 , and/or other configurations such as graded, diagonal, and other configurations. The sill  170  may be located within a depth ranging between about 0 and about 50,000 Angstroms as measured from surface  180  determined by a metrology method such as secondary ion mass spectroscopy (SIMS). The sill  170  may have a thickness ranging between about 2 Angstroms and about 250 Angstroms. The sill  170  may include Ge, SiGe, SiC, C, carbide, strained SiGe, and/or other materials.  
         [0025]     Referring to  FIG. 1   b,  illustrated is a sectional view of one embodiment of a microelectronic device  102  in an intermediate stage of manufacture according to aspects of the present disclosure. The microelectronic device  102  includes the formed electrode  150  wherein the sill  170  may be located within the region of the electrode  150 .  
         [0026]     In one embodiment, the substrate  110  may include an air gap to provide insulation for the microelectronic device  100 . For example, one structure may comprise a “silicon-on-nothing” (SON), wherein the microelectronic device  100  includes a thin insulation layer including air and/or other insulator. The microelectronic device  100  may include the sill  170  comprising SiGe with a Si cap layer located over the SiGe sill  170 . The SiGe sill  170  may be removed in a subsequent step. The Si cap layer may become a device active region for the microelectronic device  100 . The Si cap layer may be located over a gap from by the removal of the SiGe sill  140 . The gap may comprise air and/or other dielectric material.  
         [0027]     In another embodiment, a cap layer or “sill” (not shown) may be located proximate the sill  170 . Thus, multiple sill(s)  170  may be incorporated into the electrode  170 . For example, one of the multiple sill(s)  170  may include a cap layer. The cap layer may include Si, strained Si, strained SiGe, SiGe, diamond, carbide, and/or other materials. The cap layer may also be located over the sill  170 , and may be located proximate the channel region  135 . The channel  135  may be formed by a carbon nano-tube. The carbon nano-tube channel  135  may be placed over two electrodes and a heavily doped substrate  110 .  
         [0028]     Of course, the present disclosure is not limited to applications in which the microelectronic device(s)  100  is a gate structure or a transistor, or other semiconductor device. For example, in one embodiment, the microelectronic device  100  may include an electrically programmable read only memory (EPROM) cell, an electrically erasable programmable read only memory (EEPROM) cell, a static random access memory (SRAM) cell, a dynamic random access memory (DRAM) cell, a single electron transistor (SET), and/or other microelectronic devices (hereafter collectively referred to as microelectronic devices). The geometric features of the microelectronic device  100  may range between about 1300 Angstroms and about 1 Angstroms.  
         [0029]     Referring to  FIG. 2 , illustrated is a perspective view of one embodiment of a microelectronic device  200  constructed according to aspects of the present disclosure. In the illustrated embodiment, the microelectronic device  200  is a FinFET. Of course, aspects of the present disclosure are also applicable and/or readily adaptable to any type of transistor, including single-gate transistors, double-gate transistors, triple-gate transistors, and other multiple-gate transistors, and may be employed in a myriad of applications, including sensor cells, memory cells, logic cells and others.  
         [0030]     The microelectronic device  200  includes an insulator  220  formed over or integral to a substrate  210 . The microelectronic device  200  also includes first and second semiconductor features  230   a,    230   b.  In one embodiment, the semiconductor features  230   a,    230   b  are source/drain regions. The first and second semiconductor features  230   a,    230   b  are connected by a third semiconductor feature  230   c.  For example, the third semiconductor feature  230   c  may be a channel region, possibly having a dopant type opposite a dopant type of the first and second semiconductor features  230   a,    230   b.    
         [0031]     The microelectronic device  200  includes first and second contacts  240   a,    240   b  formed over corresponding ones of the semiconductor features  230   a,    230   b.  The first and second contacts  240   a,    240   b  may include Ti, Ta, Mo, Ni, TiN, TaN, CoSi, TiSi, TaSi, MoSi, NiSi, and/or other conductive materials.  
         [0032]     The microelectronic device  200  may also include a biasing feature  250  interposing the first and second semiconductor features  230   a,    230   b  and spanning the third semiconductor feature  230   c.  In one embodiment, the biasing feature  250  may be a transistor gate. For example, the biasing feature  250  may comprise doped polysilicon and/or other conductive materials such as Ti, Ta, Mo, TiN, TaN, MoSi, NiSi, and CoSi. The biasing feature  250  in the illustrated embodiment extends from at least partially between the first and second semiconductor features  230   a,    230   b,  subsequently widening and terminating at a third contact  240   c,  which is substantially similar to the first and second contacts  240   a,    240   b.  Moreover, as shown in  FIG. 2 , the biasing feature  250  may include a boss, wedge, fin or other type of protrusion  255  extending away from the semiconductor features  230   a - c.  For example, the protrusion  255  may extend to a height H 1  over the semiconductor features  230   a - c.  The microelectronic device  200  may also include a dielectric layer interposing the biasing feature  250  from one or more of the semiconductor features  230   a - c.    
         [0033]     The microelectronic device  200  further includes at least one sill  250   a.  The sill  250   a  may comprise Ge, SiGe, SiC, carbide, strained SiGe, and/or other materials. The sill  250   a  may be located within the region of the biasing feature  250 . Alternatively, the sill  250   a  may include a plurality of layers wherein there may be a germanium implant layer followed by a cap layer. The cap layer may comprise Si, SiGe, strained Si, strained SiGe, diamond, carbide, and/or other materials.  
         [0034]     Referring to  FIG. 3 , illustrated is a sectional view of one embodiment of depth adjustable sill microelectronic device  300  constructed according to aspects of the present disclosure. The microelectronic device  300  includes a substrate  302 , an isolation region  320 , and at least one microelectronic device(s)  312  and  314 .  
         [0035]     The isolation region  320  is a region that electrically isolates device(s)  312  and  314 . The isolation region  320  may include a trench filled with a dielectric material, such as shallow trench isolation. Alternatively, the isolation region  320  may be formed by an air gap. The isolation region  320  dielectric material may include a low-k dielectric material, and/or may include SiO 2 , SiN, SiC, and/or other materials.  
         [0036]     The device(s)  312 ,  314  include PMOS and/or NMOS devices. For example the device  312  may be a PMOS device wherein the sill  310   a  may be located proximately below the electrode  310 . The device  312  may also include the cap layer including Si, SiGe, strained Si, strained SiGe, SiC, diamond, carbide, and/or other materials. The location of the sill  310   a  proximate the electrode  310  provides for control of the electrode  310  and/or channel stress. The device  314  may be a NMOS device wherein the sill  310   b  may be located within the electrode  310 . The device  314  may also include the cap layer including Si, SiGe, strained Si, strained SiGe, SiC, diamond, carbide, and/or other materials. The device(s)  312 ,  314  may further include spacers  340  and contacts  350  The spacers  340  may be disposable or non-disposable. The spacers  340  may be formed of SiO 2 , SiN, polymer, and/or other materials. The contacts  350  may be formed of CoSi, TiSi, TaSi, MoSi, NiSi, and/or other conductive materials.  
         [0037]     In one embodiment, the electrode of the PMOS device  312  may be a different height than the NMOS device  314  For example, the electrode  310  of the NMOS device  314  may be partially etched prior to the formation of the sill  310   b.  Alternatively, the electrode  310  of the PMOS device  312  may be partially etched prior to the formation of the sill  310   a.    
         [0038]     Referring to  FIG. 4 , illustrated is a sectional view of one embodiment of an integrated circuit device  400  constructed according to aspects of the present disclosure. The integrated circuit device  400  is one environment in which the microelectronic device(s)  102  and/or  300  may be implemented. For example, the integrated circuit device  400  includes a plurality of microelectronic devices  102 ,  200 , and  300  wherein one or more of the microelectronic devices  102 ,  200 , and  300  may be substantially similar.  
         [0039]     The integrated circuit device  400  also includes one or more insulating layers  420 ,  430  located over the microelectronic devices  102 . The first insulating layer  420 , which may itself comprise multiple insulating layers, may be planarized to provide a substantially planar surface over the plurality of microelectronic devices  102 .  
         [0040]     The integrated circuit device  400  also includes vertical interconnects  440 , such as conventional vias or contacts, and horizontal interconnects  450  (all spatial references herein are for the purpose of example only and are not meant to limit the disclosure). The interconnects  440  may extend through one or more of the insulating layers  420 ,  430 , and the interconnects  450  may extend along one of the insulating layers  420 ,  430  or a trench formed therein. In one embodiment, one or more of the interconnects  440 ,  450  may have a dual-damascene structure. The interconnects  440 ,  450  may be formed by etching or otherwise patterning the insulating layers  420 ,  430  and subsequently filling the pattern with refractive and/or conductive material, such as tantalum nitride, copper and aluminum.  
         [0041]     Referring to  FIG. 5 , illustrated is a sectional view of one embodiment of an integrated circuit device  500  constructed according to aspects of the present disclosure. The integrated circuit device  500  is one environment in which aspects of the above-described microelectronic devices may be implemented. For example, the integrated circuit device  500  includes a plurality of microelectronic devices  510  located on or in a substrate  530 , one or more of which is substantially similar to one or more of the microelectronic devices  102 ,  200 ,  300  shown in  FIGS. 1-3 , respectively. The microelectronic devices  510  may be interconnected and/or connected to one or more other microelectronic devices  520  manufactured on or in the substrate  530 . The microelectronic devices  520  may be or comprise metal-oxide-semiconductor field-effect-transistor (MOSFET), FinFETs and/or other conventional or future-developed semiconductor devices.  
         [0042]     The integrated circuit device  500  also includes interconnects  540  extending along and/or through one or more dielectric layers  550  to ones of the plurality of microelectronic devices  510 . The dielectric layers  550  may comprise silicon dioxide, Black Diamonds (a product of Applied Materials of Santa Clara, Calif.) and/or other materials, and may be formed by CVD, ALD, PVD, spin-on coating and/or other processes. The dielectric layers  550  may have a thickness ranging between about 50 Angstroms and about 15,000 Angstroms. The interconnects  540  may include copper, tungsten, gold, aluminum, carbon nano-tubes, carbon fullerenes, a refractory metals and/or other materials, and may be formed by CVD, ALD, PVD and/or other processes.  
         [0043]     It is understood, that the present disclosure contemplates the crystalline perturbation of the microelectronic device  100 , more specifically, the crystalline perturbation of the electrode  170  and/or a proximate region of a microelectronic structure. The present disclosure may be utilized to provide balancing of electrical characteristics and/or the crystalline stress of a plurality of microelectronic device(s) of integrated circuit  500 . For example, predetermined areas of substrate  110  may have openings through mask  160  wherein sill  170  may be located. Therefore, at least one microelectronic device  102 ,  200 , and  300  may have sill  170 , while other device(s)  102 ,  200 , and  300  may not have sill  170 . Alternatively, the impurity concentration of sill  170  may be different for a plurality of device(s)  102 ,  200 , and  300 . Thus, the control of the variation of sill  170  properties provides balancing of electrical properties and/or the crystalline stress of a predetermined population of microelectronic device(s)  102 ,  200 , and  300  of integrated circuit  500 .  
         [0044]     Although embodiments of the present disclosure have been described in detail, those skilled in the art should understand that they may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure. Accordingly, all such changes, substitutions and alterations are intended to be included within the scope of the present disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.

Technology Category: 5