Patent Publication Number: US-11646358-B2

Title: Sacrificial fin for contact self-alignment

Description:
BACKGROUND 
     The present invention relates generally to semiconductor devices, and more specifically, to a placement of a contact landing on a sacrificial fin with self-alignment capability. 
     A Field Effect Transistor (FET) usually has a source, a channel, and a drain, where current flows from the source to the drain, and a gate that controls the flow of current through the channel. FETs can have a variety of different structures, for example, FETs have been fabricated with the source, channel, and drain formed in the substrate material itself, where the current flows horizontally (e.g., in the plane of the substrate), and finFETs have been formed with the channel extending outward from the substrate, but where the current also flows horizontally from a source to a drain. A vertical finFET can also be configured with a bottom source/drain in the substrate and a top source/drain on the vertical fin, where the current then flows in a direction perpendicular to the substrate. The channel for the finFET can usually be an upright slab of thin rectangular Si, commonly referred to as the fin with a gate on the fin. Depending on the doping of the source and drain, an n-FET or a p-FET can be formed. Examples of FETs can include a metal-oxide-semiconductor field effect transistor and an insulated-gate field-effect transistor. Two FETs also can be coupled to form a complementary metal oxide semiconductor (CMOS), where a p-channel MOSFET and n-channel MOSFET are coupled together. 
     With ever decreasing device dimensions, forming the individual components and electrical contacts becomes more difficult. An approach is therefore needed that retains the positive aspects of traditional FET structures, while overcoming the scaling issues created by forming smaller device components. 
     SUMMARY 
     In accordance with an embodiment, a method is provided for forming a self-aligned middle-of-the-line (MOL) contact in MOL processing. The method includes forming a fin structure over a substrate, depositing and etching a first set of dielectric layers over the fin structure, etching the fin structure to form a sacrificial fin and a plurality of active fins, depositing a work function metal (WFM) layer over the plurality of active fins, depositing an inter-layer dielectric (ILD) over the sacrificial fin and the plurality of active fins, depositing a second set of dielectric layers, etching the second set of dielectric layers and the ILD to form a first via portion and to expose a top surface of the sacrificial fin, removing the sacrificial fin to form a second via portion; and filling the first and second via portions with a conductive material to form the self-aligned MOL contact in the first via. portion and a contact landing in the second via portion such that the contact landing separates the self-aligned MOL contact from the substrate. 
     In accordance with another embodiment, a method is provided for forming a self-aligned middle-of-the-line (MOL) contact in MOL processing. The method includes forming a sacrificial fin and a plurality of active fins over a substrate by employing a U-shaped mandrel, depositing a work function metal (WFM) layer over the plurality of active fins, depositing an inter-layer dielectric (ILD) over the sacrificial fin and the plurality of active fins, depositing dielectric layers over the ILD, etching the dielectric layers and the ILD to form a first via portion extending to a top surface of the sacrificial fin, removing the sacrificial fin to form a second via portion, and filling the first and second via portions with a conductive material to form the self-aligned MOL contact in the first via portion and a contact landing in the second via portion. 
     In accordance with yet another embodiment, a semiconductor structure is provided for forming a self-aligned middle-of-the-line (MOL) contact in MOL processing. The semiconductor structure includes a first MOL, contact disposed over an active fin formed over a substrate and a second MOL contact disposed over a contact landing, wherein the contact landing separates the second. MOL contact from the substrate. 
     It should be noted that the exemplary embodiments are described with reference to different subject-matters. In particular, some embodiments are described with reference to method type claims whereas other embodiments have been described with reference to apparatus type claims. However, a person skilled in the art will gather from the above and the following description that, unless otherwise notified, in addition to any combination of features belonging to one type of subject-matter, also any combination between features relating to different subject-matters, in particular, between features of the method type claims, and features of the apparatus type claims, is considered as to be described within this document. 
     These and other features and advantages will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will provide details in the following description of preferred embodiments with reference to the following figures wherein: 
         FIG.  1    is a cross-sectional view of a semiconductor structure including a mandrel formed over a fin structure, in accordance with an embodiment of the present invention; 
         FIG.  2    is a cross-sectional view of the semiconductor structure of  FIG.  1    where a spacer is deposited, in accordance with an embodiment of the present invention; 
         FIG.  3    is a cross-sectional view of the semiconductor structure of  FIG.  2    where the spacer is etched back, in accordance with an embodiment of the present invention; 
         FIG.  4    is a cross-sectional view of the semiconductor structure of  FIG.  3    where the mandrel is removed, in accordance with an embodiment of the present invention; 
         FIG.  5    is a cross-sectional view of the semiconductor structure of  FIG.  4    where a block mask is deposited, in accordance with an embodiment of the present invention; 
         FIG.  6    is a top view of the semiconductor structures of  FIGS.  1 - 5   , in accordance with an embodiment of the present invention; 
         FIG.  7    is a cross-sectional view of the semiconductor structure of  FIG.  5    where the spacer portions are removed and dielectric layers are etched to expose a top surface of the fin structure, in accordance with an embodiment of the present invention; 
         FIG.  8    illustrates cross-sectional views of the semiconductor structure of  FIG.  7    along an X-direction and along a Y-direction, where the fin structure is etched, in accordance with an embodiment of the present invention; 
         FIG.  9    illustrates cross-sectional views of the semiconductor structure of  FIG.  8    along an X-direction and along a Y-direction, where a bottom spacer is deposited, in accordance with an embodiment of the present invention; 
         FIG.  10    illustrates cross-sectional views of the semiconductor structure of  FIG.  9    along an X-direction and along a Y-direction, where a bottom epi is formed, and a work function metal (WFM) layer is deposited and selectively etched, in accordance with an embodiment of the present invention; 
         FIG.  11    illustrates cross-sectional views of the semiconductor structure of  FIG.  10    along an X-direction and along a Y-direction, where an inter-layer dielectric (ILD) is deposited and planarized, in accordance with an embodiment of the present invention; 
         FIG.  12    illustrates cross-sectional views of the semiconductor structure of  FIG.  11    along an X-direction and along a Y-direction, where the is selectively etched to a top surface of the fin structure, a top epi region is deposited, and dielectric regions are deposited over the top epi, in accordance with an embodiment of the present invention; 
         FIG.  13    illustrates cross-sectional views of the semiconductor structure of  FIG.  12    along an X-direction and along a Y-direction, where a via is formed and filled with a conductive material, in accordance with an embodiment of the present invention; and 
         FIG.  14    is a cross-sectional view of the semiconductor structure depicting a pillar formed between the substrate and the CR contact, in accordance with an embodiment of the present invention. 
     
    
    
     Throughout the drawings, same or similar reference numerals represent the same or similar elements. 
     DETAILED DESCRIPTION 
     Embodiments in accordance with the present invention provide methods and devices for employing Self-Aligned-Double-Patterning (SADP) sacrificial fins for self-aligned middle-of-the-fine (MOL) contacts. The goal in integrated circuit fabrication is to accurately reproduce the original circuit design on the integrated circuit product. Historically, the feature sizes and pitches employed in integrated circuit products were such that a desired pattern could be formed using a single patterned photoresist masking layer. However, in recent years, device dimensions and pitches have been reduced to the point where existing photolithography tools, e.g., 193 nm wavelength immersion photolithography tools, cannot form a single patterned mask layer with all of the features of the overall target pattern. Accordingly, device designers have resorted to techniques that involve performing multiple exposures to define a single target pattern in a layer of material. One such technique is generally referred to as multiple patterning, e.g., double patterning. Generally speaking, double patterning is an exposure method that involves splitting (dividing or separating) a dense overall target circuit pattern into two separate, less-dense patterns. The simplified, less-dense patterns are then printed separately on a wafer utilizing two separate masks (where one of the masks is utilized to image one of the less-dense patterns, and the other mask is utilized to image the other less-dense pattern). Further, in some cases, the second pattern is printed in between the lines of the first pattern such that the imaged wafer has, for example, a feature pitch which is half that found on either of the two less-dense masks. This technique effectively lowers the complexity of the photolithography process, improving the achievable resolution and enabling the printing of far smaller features that would otherwise be difficult using existing photolithography tools. The SADP process is one such multiple technique. The SADP process can be an attractive solution for manufacturing next-generation devices, particularly metal routing lines on such next-generation devices, due to better overlay control that is possible when using an SADP process. 
     Semiconductor fabrication, traditionally including Front-End-Of-The-Line (FEOL), Middle-Of-The-tine, (MOL), and Back-End-Of-The-Line (BEOL), constitutes the entire process flow for manufacturing modern computer chips. The usual FEOL processes include wafer preparation, isolation, well formation, gate patterning, spacer, extension and source/drain implantation, silicide formation, and dual stress liner formation. The BEOL processes include dielectric film deposition, patterning, metal fill and planarization by chemical mechanical polishing. The MOL is mainly gate contact formation, which is an increasingly challenging part of the whole fabrication flow, particularly for lithography patterning. MOL contacts can have a narrow pitch area with a very high aspect ratio. A pitch refers to a minimum center-to-center distance between interconnect lines. Lithographic overlay can jeopardize the device if the MOL contact shorts the work function metal (WFM) because there is no self-alignment. 
     The exemplary embodiments of the present invention alleviate such shortcomings by enabling a placement of a contact landing on a SADP sacrificial fin with self-alignment capability. The sacrificial fin is employed to self-align the MOL contact (CR) to maintain a very small critical dimension (CD), as opposed to increasing surface area of the contact. 
     It is to be understood that the present invention will be described in terms of a given illustrative architecture; however, other architectures, structures, substrate materials and process features and steps/blocks can be varied within the scope of the present invention. It should be noted that certain features cannot be shown in all figures for the sake of clarity. This is not intended to be interpreted as a limitation of any particular embodiment, or illustration, or scope of the claims. 
     The structures of the present invention can be manufactured in a number of ways using a number of different tools. In general, though, the methodologies and tools are used to form structures with dimensions in the micrometer and nanometer scale. The methodologies, e.g., technologies, employed to manufacture the structures have been adopted from integrated circuit (IC) technology. For example, the structures of the present invention are built on wafers and are realized in films of material patterned by photolithographic processes on the top of a wafer. In particular, the fabrication of the structures of the present invention employs three basic building blocks: deposition of thin films of material on a substrate, applying a patterned mask on top of the films by photolithographic imaging, and etching the films selectively to the mask. 
       FIG.  1    is a cross-sectional view of a semiconductor structure including a mandrel formed over a fin structure, in accordance with an embodiment of the present invention. 
     The semiconductor structure  5  includes a fin structure  12  formed over a substrate  10 . A stack of dielectric layers are deposited over the fin structure  12 . The stack of dielectric layers includes a bottom nitride layer  14 , a first oxide layer  16 , a top nitride layer  18 , and a second oxide layer  20 . A mandrel layer  22  is deposited and patterned over the stack of dielectric layers. The patterning results in openings  24 . 
     The substrate  10  can be crystalline, semi-crystalline, microcrystalline, or amorphous. The substrate  10  can be essentially (e.g., except for contaminants) a single element (e.g., silicon), primarily (e.g., with doping) of a single element, for example, silicon (Si) or germanium (Ge), or the substrate  10  can include a compound, for example, GaAs, SiC, or SiGe. The substrate  10  can also have multiple material layers. In some embodiments, the substrate  10  includes a semiconductor ate al including, but not necessarily limited to, silicon (Si), silicon germanium (SiGe), silicon carbide (SiC), Si:C (carbon doped silicon), silicon germanium carbide (SiGeC), carbon doped silicon germanium (SiGe:C), III-V (e.g., GaAs, AlGaAs, InAs, InP, etc.), II-V compound semiconductor (e.g., ZnSe, ZnTe, ZnCdSe, etc.) or other like semiconductor. In addition, multiple layers of the semiconductor materials can be used as the semiconductor material of the substrate  10 . In some embodiments, the substrate  10  includes both semiconductor materials and dielectric materials. The semiconductor substrate  10  can also include an organic semiconductor or a layered semiconductor such as, for example, Si/SiGe, a silicon-on-insulator or a SiGe-on-insulator. A portion or entire semiconductor substrate  10  can be amorphous, polycrystalline, or monocrystalline. In addition to the aforementioned types of semiconductor substrates, the semiconductor substrate  10  employed in the present invention can also include a. hybrid oriented (HOT) semiconductor substrate in which the HOT substrate has surface regions of different crystallographic orientation. 
     As used herein, a “fin structure”  12  refers to a semiconductor material, which is employed as the body of a semiconductor device, in which the gate structure is positioned around the fin structure such that charge flows down the channel on the two sidewalk of the fin structure and optionally along the top surface of the fin structure. A Fin Field Effect Transistor (FinFET) is a semiconductor device that positions the channel region of the semiconductor device in a fin structure. 
     The material that provides the fin structure  12  can be a silicon-containing material, such as single crystal silicon (Si), monocrystalline silicon (Si), polycrystalline silicon (Si) or a combination thereof. In some embodiments, the fin structure  12  can be formed from a semiconductor on insulator (SOI) substrate, in which the upper layer of the SOI substrate, SOI layer, provides the material for the fin structure  12 . 
     The dielectric layers  14 ,  16 ,  18 ,  20  can include, but are not limited to, SiN, SiOCN, SiC, SiOC, SiBCN, SO 2 , SiO 2 , or ultra-low-k (ULK) materials, such as, for example, porous silicates, carbon doped oxides, silicon dioxides, silicon nitrides, silicon oxynitrides, carbon-doped silicon oxide (SiCOH) and porous variants thereof, silsesquioxanes, siloxanes, or other dielectric materials having, for example, a dielectric constant in the range of about 2 to about 10. 
     In some embodiments, the dielectric layers  14 ,  16 ,  28 ,  20  can be conformally deposited using atomic layer deposition (ALD) or, chemical vapor deposition (CVD). Variations of CVD processes suitable for forming the dielectric layers  14 ,  16 ,  18 ,  20  include, but are not limited to, Atmospheric Pressure CVD (APCVD), Low Pressure CVD (LPCVD) and Plasma Enhanced CVD (PECVD), Metal-Organic CVD (MOCVD) and combinations thereof can also be employed. 
     The oxide layers can be made of, for example, silicon dioxide (SiO 2 ). In some embodiments, the oxide layers can be made of, for example, a low-k dielectric material, e.g., SiCOH, SiC, SiCN, SiN, other dielectric material or combinations thereof 
     In some embodiments, mandrel portions  22  are formed of amorphous silicon (a-Si) or another material that has a high etching selectivity with the underlying dielectric layers  14 ,  16 ,  18 ,  20 . 
     The mandrel material can be deposited, for example, by CVD or spin coating. The thickness of the mandrel material can be from 30 nm to 300 nm, although lesser and greater thicknesses can also be employed. 
       FIG.  2    is a cross-sectional view of the semiconductor structs re of  FIG.  1    where a spacer is deposited, in accordance with an embodiment of the present invention. 
     In some embodiments, a spacer  26  can be formed using a sidewall image transfer (SIT) technique. The spacer  26  is formed over the mandrel  22 . 
     The material of spacer  26  is selected to have a high etching selectivity with top layers  18  and  20 . For example, the material of spacer  26  can be selected from AlO, AN, AlON, TaN, TiN, TiO, Si, SiO 2 , SiN, metals, and metal alloys. 
     In some embodiments, the mandrel portions  22  can be polysilicon, the spacers  24  can be nitride, and the dielectric layers  16 ,  20  can be an oxide. In other embodiments, the dielectric layers  14 ,  18  can include nitride, the mandrel portions  22  can include amorphous carbon, and the spacers  24  can include a metal, such as titanium nitride (TiN), or oxide. 
       FIG.  3    is a cross-sectional view of the semiconductor structure of  FIG.  2    where the spacer is etched back, in accordance with an embodiment of the present invention. 
     In various example embodiments, the spacer  26  is etched back. The spacer etch results in vertical spacer portions  28 , as well as opening  29  in a non-mandrel section. 
     Etching of the spacer  26  includes an anisotropic etch and can include any appropriate dry etch chemistry such as reactive ion etching (RIE) with an etchant including CF 4 , CH 3 F, CH 2 F 2 , and/or any combination of CxFy in conjunction with O 2 , N 2  and Ar. 
       FIG.  4    is a cross-sectional view of the semiconductor structure of  FIG.  3    where the mandrel is removed, in accordance with an embodiment of the present invention. 
     In various example embodiments, the mandrel is removed  22 . Each mandrel structure can be removed by an etching process that is selective to the vertical spacer portions  28  and the top layer  18 . The removal of the mandrel  22  results in openings  30  formed between the spacer portions  28 . 
       FIG.  5    is a cross-sectional view of the semiconductor structure of  FIG.  4    where a block mask is deposited, in accordance with an embodiment of the present invention. 
     In various example embodiments, a mask layer  32  is deposited over a portion of the structure. Mask layer  32  can be referred to as a block mask. Mask layer  32  can be any suitable resist. Suitable resists include photoresists, electron-beam resists, ion-beam resists, X-ray resists, and etchant resists. The resist can include a polymeric material, for example, that can be applied by spin casting. The mask can be removed by, for example, an asking process. 
     Mask layer  32  can be formed by spin coating a photo resist material followed by photolithography to form one or more of opening(s). 
     The right-hand side of the structure that does not include the mask layer  32  can be referred to as the open cut area. 
     Mask layer  32  can be subsequently removed, for example, using a solvent or an aqueous developer, for example, using N-methyl-2-pyrrolidone (NMP), toluene, propylene glycol methyl ether acetate (PGMEA), tetramethylammonium hydroxide (TMAH), or a combination including at least one of the foregoing. 
       FIG.  6    is a top view of the semiconductor structures of  FIGS.  1 - 5   , in accordance with an embodiment of the present invention. 
     In various example embodiments, the top view  40  illustrates the U-shaped mandrel portions  22 . 
     The top view  42  illustrates the spacer portions  28  formed adjacent the mandrel portions  22 . 
     The top view  44  illustrates the removal of mandrel portions  22 . Thus, only spacer portions  28  remain. The spacer portions  28  form a substantially U-shaped configuration. 
     The top view  46  illustrates application of the block mask  32 . 
       FIG.  7    is a cross-sectional view of the semiconductor structure of  FIG.  5    where the spacer portions are removed and dielectric layers are etched to expose a top surface of the fin structure, in accordance with an embodiment of the present invention. 
     In various example embodiments, in structure  35 , the spacer portions  28  are etched away, and portions of the dielectric layers  14 ,  16  are selectively etched such that nitride layer  14 ′ and oxide layer  16 ′ remain. 
     Top view  48  illustrates the substrate  10  and the fin structures  12  formed over the substrate  10 . 
       FIG.  8    illustrates cross-sectional views of the semiconductor structure of  FIG.  7    along an X-direction and along a Y-direction, where the fin structure is etched, in accordance with an embodiment of the present invention. 
     In various example embodiments, structure  50 , which is a cross-sectional view taken along the X direction (along the fin) in top view  48 , depicts etching of the fin structure  12 . This results in remaining fin structures  12 ′,  12 ″ and the exposure of top surface  11  of substrate  10 . An opening  52  is illustrated between fins structures  12 ′,  12 ″. 
     In various example embodiments, structure  55 , which is a cross-sectional view taken along the Y direction (across the tin) in top view  48 , depicts etching of the fin structure  12 . This results in openings  52  formed between remaining fin structures  12 ′. The fins  12 ′ include remaining nitride layer portions  14 ′ and remaining oxide layer portions  16 ′. 
     Fins  12 ′ are active fins, whereas fin  12 ″ is a sacrificial fin. It is noted that the left fin structure  12 ″ (thin fin) is the sacrificial fin, whereas the right fin structures  12 ′ (fat fin) are active fins. The subsequent removal of the sacrificial fin  12 ″ (thin fin) will enable placement of the CR MOL contact ( FIG.  13   ). A width of the sacrificial fin  12 ″ is less than a width of each of the plurality of active fins  12 ′. 
       FIG.  9    illustrates cross-sectional views of the semiconductor structure of  FIG.  8    along an X-direction and along a Y-direction, where a bottom spacer is deposited, in accordance with an embodiment of the present invention. 
     In various example embodiments, structure  60 , which is a cross-sectional view taken along the X direction in top view  48 , depicts depositing of a bottom spacer  62 , Bottom spacer  62  is formed between the fin structures  12 ′,  12 ″. Additionally, the remaining oxide layer portions  16 ′ are removed to expose a top surface  15  of the remaining nitride layer portions  14 ′. 
     In various example embodiments, structure  65 , which is a cross-sectional view taken along the Y direction in top view  48 , depicts the removal of the remaining oxide layer portions  16 ′ and the deposition of the bottom spacer  62  between the fin structures  12 ′. 
       FIG.  10    illustrates cross-sectional views of the semiconductor structure of  FIG.  9    along an X-direction and along a Y-direction, where a bottom epi is formed, and a work function metal (WFM) layer is deposited and selectively etched, in accordance with an embodiment of the present invention. 
     In various example embodiments, structures  70  and  80  are cross-sectional views taken along the X direction in top view  48 , where a work function metal (WFM) layer  72  is deposited and selectively etched. An epi layer  74  is also formed under the fin structures  12 ′,  12 ″. The epi layer  74  is formed directly underneath the bottom spacer  62 . The WFM layer  72  is selectively etched everywhere except for the active fin regions (structure  80 ). 
     In various example embodiments, structures  75  and  85  are cross-sectional views taken along the Y direction in top view  48 , where the WFM layer  72  and the epi layers  74 . 
     In various embodiments, the WFM layer  72  can be a nitride, including but not limited to titanium nitride (TiN), titanium aluminum nitride (TiAlN), hafnium nitride (HN), hafnium silicon nitride (HtSiN), tantalum nitride (TaN), tantalum silicon nitride (TaSiN), tungsten nitride (WN), molybdenum nitride (MoN), niobium nitride (NbN); a carbide, including but not limited. to titanium carbide (TiC), titanium aluminum carbide (TiAlC),titanium aluminum carbide (TiAlC), tantalum carbide (TaC), hafnium carbide (HfC), and combinations thereof. 
     Non-limiting examples of suitable work function metals include p-type work function metal materials and n-type work function metal materials. P-type work function materials include compositions such as ruthenium, palladium, platinum, cobalt, nickel, and conductive metal oxides, or any combination thereof. N-type metal materials include compositions such as hafnium, zirconium, titanium, tantalum, aluminum, metal carbides (e.g., hafnium carbide, zirconium carbide, titanium carbide, and aluminum carbide), aluminides, or any combination thereof. 
     Generally, regarding epi layers  74 , epitaxial growth, deposition, formation, etc. means the growth of a semiconductor material on a deposition or seed surface of a semiconductor material, in which the semiconductor material being grown has the same crystalline characteristics as the semiconductor material of the deposition surface. In an epitaxial deposition process, the chemical reactants provided by the source gasses are controlled and the system parameters are set so that the depositing atoms arrive at, the deposition surface of the semiconductor material with sufficient energy to move around on the surface and orient themselves to the crystal arrangement of the atoms of the deposition surface. Therefore, an epitaxial a has the same crystalline characteristics as the deposition surface on which it is formed. For example, an epitaxial material deposited on a &lt;100&gt; crystal surface will take on a &lt;100&gt; orientation. 
     Examples of various epitaxial growth processes include, for example, rapid thermal chemical vapor deposition (RTCVD), low-energy plasma deposition (LEPD), ultra-high vacuum chemical vapor deposition (UHVCVD), atmospheric pressure chemical vapor deposition (APCVD), liquid-phase epitaxy (LPE), molecular beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD). The temperature for an epitaxial growth process can range from, for example, 550° C. to 900° C., but is not necessarily limited thereto, and can be conducted at higher or lower temperatures as needed. 
       FIG.  11    illustrates cross-sectional views of the semiconductor structure of FIG,  10  along an X-direction and along a Y-direction, where an inter-layer dielectric (ILD) is deposited and plagiarized, in accordance with an embodiment of the present invention. 
     In various example embodiments, structures  90  and  100  are cross-sectional views taken along the X direction in top view  48 , where an interlayer dielectric (ILD)  92  is deposited and planarized. The ILD  92  is planarized such that a top surface of the ILD is flush or level with the top surface of WFM layer  72 . 
     In various example embodiments, structures  95  and  105  are cross-sectional views taken along the Y direction in top view  48 , where the ILD  92  is deposited and planarized. After planarization, the ILD  92  can be designated as ILD sections  92 ′. 
     The ILD  92  can include any materials known in the art, such as, for example, porous silicates, carbon doped oxides, silicon dioxides, silicon nitrides, silicon oxynitrides, or other dielectric materials. The ILD  92  can be formed using any method known in the art, such as, for example, chemical vapor deposition, plasma enhanced chemical vapor deposition, atomic layer deposition, or physical vapor deposition. The ILD  92  can have a thickness ranging from about 200 nm to about 2000 nm as deposited, 
     The dielectric material of layer  92  can include, but is not limited to, ultra-low-k (ULK) materials, such as, for example, porous silicates, carbon doped oxides, silicon dioxides, silicon nitrides, silicon oxynitrides, carbon-doped silicon oxide (SiCOH) and porous variants thereof, silsesquioxanes, siloxanes, or other dielectric materials having, for example, a dielectric constant in the range of about 2 to about 4. 
     One example of a material suitable for the low-k materials for the low-k dielectric layer  92  can include silicon oxycarbonitride (SiOCN). Other low-k materials that can also be used for the low-k material layer  92  can include fluorine doped silicon dioxide, carbon doped silicon dioxide, porous silicon dioxide, porous carbon doped silicon dioxide, organosilicate glass (OSG), diamond-like carbon (DLC) and combinations thereof. 
       FIG.  12    illustrates cross-sectional views of the semiconductor structure of  FIG.  11    along an X-direction and along a Y-direction, where the ILD is selectively etched to a top surface of the fin structure, a top epi region is grown, and dielectric regions are deposited over the top epi, in accordance with an embodiment of the present invention. 
     In various example embodiments, structures  110 ,  120 ,  130  are cross-sectional views taken along the X direction in top view  48 , where remaining nitride layer portions  14 ′ are removed to expose top surfaces  13 ,  13 ′ of the remaining fin structures  12 ′,  12 ″, respectively. Openings  111  are formed over the remaining fin structures  12 ′,  12 ″. In structure  120 , a top epi layer  122  is grown over the active fin structures  12 ′ only (active fins). A pair of dielectrics layers  124 ,  126  can be deposited thereafter. In one example, dielectric layer  124  is a nitride layer and dielectric layer  126  is an oxide layer. In structure  130 , a mask layer  132  is deposited over the dielectric layers  124 ,  126 , and a via  134  is formed through the mask layer  132 , the dielectric layers  124 ,  126 , and the ILD  92 ′, the via  134  exposing a top surface  13 ′ of the non-active fin structure. The opening  111  also results in WFM sections  72 ′ remaining adjacent active fins  12 ′. 
     In various example embodiments, structures  115 ,  125 ,  135  are cross-sectional views taken along the Y direction in top view  48 , where the ILD is etched to expose the top surfaces  13 ,  13 ′ of the remaining fin structures  12 ′,  12 ″, respectively, dielectric layers  124 ,  126  are deposited, a mask layer  132  is deposited, and a via  134  is formed (not shown in Y-direction). 
     Non-limiting examples of suitable dielectric layers  124 ,  126  include silicon dioxide, tetraethylorthosilicate (TEOS) oxide, high aspect ratio plasma (HARP) oxide, silicon oxide, high temperature oxide (HTO), high density plasma (HDP) oxide, oxides formed by an atomic layer deposition (ALD) process, silicon nitride, silicon oxynitride, or any combination thereof. 
     Non-limiting examples of suitable materials for the dielectric layers  124 ,  126  include oxides, nitrides, oxynitrides, silicates (e.g., metal silicates), alun inates, titanates, nitrides, or any combination thereof. 
       FIG.  13    illustrates cross-sectional views of the semiconductor structure of  FIG.  12    along an X-direction and along a Y-direction, where a via is formed and filled with a conductive material, in accordance with an embodiment of the present invention. 
     In various example embodiments, structures  140 ,  150  are cross-sectional views taken along the X direction in top view  48 , where the exposed non-active or sacrificial fin  12 ″ is removed to form via  142  and the via  142  is filled with a conductive material  152  to form contact  152  (CR). Additionally, contacts  154  (CA) and  156  (CB) are formed. The mask layer  132  is also removed thus exposing the top surface  127  of the dielectric layer  126 . 
     In various example embodiments, structures  145 ,  155  are cross-sectional views taken along the Y direction in top view  48 . This directional cut does not depict the formation of the contact landing. 
     Structure  160  further illustrates the contacts  152 ,  154 ,  156 , The contact  152  (CR) is formed such that a lower portion or section or region defines a contact landing  153 . The contact landing  153  is narrower or thinner than the contact  152  (CR). Thus, the contact  152  (CR) does not directly contact the substrate  10 . Instead, contact landing  153  separates the CR contact  152  from the substrate  10 . The placement of the contact landing  153  of the CR contact  152  on a sacrificial fin enables self-alignment capability. Thus, the CA contact  154  directly contacts the active fin structure  12 ′, the CB contact  156  directly contacts the substrate  10 , and the CR MOL contact act  152  is formed over and in direct contact with a contact landing  153 , the contact landing  153  taking the place of the sacrificial fin  12 ″. 
     The conductive material can be any conductive materials known in the art, such as, for example, copper (Cu), aluminum (Al), tungsten (W), ruthenium (Ru) or cobalt (Co). The conductive layer can be fabricated using any technique known in the art. 
     Non-limiting examples of suitable conductive materials include doped polycrystalline or amorphous silicon, germanium, silicon germanium, a metal (e.g., tungsten, titanium, tantalum, ruthenium, zirconium, cobalt, copper, aluminum, lead, platinum, tin, silver, gold), a conducting metallic compound material (e.g., tantalum nitride, titanium nitride, tantalum carbide, titanium carbide, titanium aluminum carbide, tungsten silicide, tungsten nitride, ruthenium oxide, cobalt silicide, nickel silicide), carbon nanotube, conductive carbon, grapheme, or any suitable combination of these materials. The conductive material can further include dopants that are incorporated during or after deposition. The conductive metal can be deposited by a suitable deposition process, for example, CVD, PECVD, PVD, plating, thermal or e-beam evaporation, and sputtering. 
       FIG.  14    is a cross-sectional view of the semiconductor structure depicting a pillar formed between the substrate and the CR contact, in accordance with an embodiment of the present invention. 
     Structure  170  illustrates the contact  152  (CR) formed on a contact landing  153 . Thus, the contact  152  (CR) does not directly contact the substrate  10 . Instead, contact landing  153  separates the CR contact  152  from the substrate  10 . The contact landing  153  is thinner than the CR contact  152 . The contact landing  153  is defined by the width of the fin structure  12 ″. The placement of the contact landing  153  of the CR contact  152  on a sacrificial fin enables self-alignment capability. Shallow trench isolation (STI) regions  171  can separate several substrates  10  from each other. Sonic substrates  10  can include active fins only and some substrates  10  can include active fins  12 ′ and inactive fins  12 ″. The active fins  12 ′ directly contact WFM layer portions  72 ′. The inactive fin  12 ″ separates the CR contact  152  from the substrate  10 . Additionally, a critical dimension of the self-aligned MOL contact is defined by a width of the sacrificial ftn  12 ″. 
     In summary, the exemplary embodiments enable placement of a contact landing on a SADP sacrificial fin with self-alignment capability. The sacrificial fin is employed to self-align the MOL contact (CR) to maintain a very small critical dimension (CD), as opposed to increasing surface area of the contact. 
     Regarding  FIGS.  1 - 14   , deposition is any process that grows, coats, or otherwise transfers a material onto the wafer. Available technologies include, but are not limited to, thermal oxidation, physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), molecular bea.m epitaxy (MBE) and more recently, atomic layer deposition (ALD) among others. As used herein, “depositing” can include any now known or later developed techniques appropriate for the material to be deposited including but not limited to, for example: chemical vapor deposition (CVD), low-pressure CVD (LPCVD), plasma-enhanced CVD (PECVD), semi-atmosphere CVD (SACVD) and high density plasma. CM (HDPCVD), rapid thermal CVD (RTCVD), ultra-high vacuum CND (UHVCVD), limited reaction processing CVD (LRPCVD), metal-organic CVD (MOCVD), sputtering deposition, ion beam deposition, electron beam deposition, laser assisted deposition, thermal oxidation, thermal nitridation, spin-on methods, physical vapor deposition (PVD), atomic layer deposition (ALD), chemical oxidation, molecular beam epitaxy (MBE), plating, evaporation. 
     The term “processing” as used herein includes deposition of material or photoresist, patterning, exposure, development, etching, cleaning, stripping, implanting, doping, stressing, layering, and/or removal of the material or photoresist as needed in forming a described structure. 
     Removal is any process that removes material from the wafer: examples include etch processes (either wet or dry), and chemical-mechanical planarization (CMP), etc. 
     Patterning is the shaping or altering of deposited materials, and is generally referred to as lithography. For example, in conventional lithography, the wafer is coated with a chemical called a photoresist; then, a machine called a stepper focuses, aligns, and moves a mask, exposing select portions of the wafer below to short wavelength light; the exposed regions are washed away by a developer solution. After etching or other processing, the remaining photoresist is removed. Patterning also includes electron-beam lithography. 
     Semiconductor lithography is the formation of three-dimensional relief images or patterns on the semiconductor substrate for subsequent transfer of the pattern to the substrate. In semiconductor lithography, the patterns are formed by a light sensitive polymer called a photo-resist. To build the complex structures that make up a transistor and the many wires that connect the millions of transistors of a circuit, lithography and etch pattern transfer steps are repeated multiple times. Each pattern being printed on the wafer is aligned to the previously formed patterns and slowly the conductors, insulators and selectively doped regions are built up to form the final device. 
     A pre-clean wet etch process, such as a buffered hydrofluoric acid (BHF) etch, is a material removal process that uses liquid chemicals or etchants to remove materials from a surface. BHF is a mixture of a buffering agent and hydrofluoric acid (HF). The buffering agent provides a greater process control than HF alone and can be, for example, ammonium fluoride (NH 4 F). Wet etch processes, such as BHF, can advantageously remove native silicon oxide or silicon nitride films during an epitaxy pre-clean. 
     A pre-clean dry etch process, such as, for example, an in-situ pre-clean etch process, uses an in-situ remote plasma assisted dry etch process which involves the simultaneous exposure of a substrate to H 2 , NF 3  and NH 3  plasma by-products. Remote plasma excitation of the hydrogen and fluorine species allows plasma-damage-free substrate processing. The resulting etch is largely conformal and selective towards silicon oxide layers but does not readily etch silicon regardless of whether the silicon is amorphous, crystalline or polycrystalline. This selectivity provides advantages for applications such as shallow trench isolation (STI) and ILD recess formation and cleaning. A dry etch process can produce solid by-products which grow on the surface of the substrate as substrate material is removed. These solid by-products can be subsequently removed via sublimation when the temperature of the substrate is raised. 
     It is to be understood that the present invention will be described in terms of a given illustrative architecture; however, other architectures, structures, substrate materials and process features and steps/blocks can be varied within the scope of the present invention. 
     It will also be understood that when an element such as a layer, region or substrate is referred to as being “on” or “over” another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being “directly on” or “directly over” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements can be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. 
     The present embodiments can include a design for an integrated circuit chip, which can be created in a graphical computer programming language, and stored in a computer storage medium (such as a disk, tape, physical hard drive, or virtual hard drive such as in a storage access network). If the designer does not fabricate chips or the photolithographic masks used to fabricate chips, the designer can transmit the resulting design by physical mechanisms (e.g., by providing a copy of the storage medium storing the design) or electronically (e.g., through the Internet) to such entities, directly or indirectly. The stored design is then converted into the appropriate format (e.g., GDSII) for the fabrication of photolithographic masks, which include multiple copies of the chip design in question that are to be formed on a wafer. The photolithographic masks are utilized to define areas of the wafer to be etched or otherwise processed. 
     Methods as described herein can be used in the fabrication of integrated circuit chips. The resulting integrated circuit chips can be distributed by the fabricator in raw wafer form (that is, as a single wafer that has multiple unpackaged chips), as a bare die, or in a packaged form. In the latter case, the chip is mounted in a single chip package (such as a plastic carrier, with leads that are affixed to a motherboard or other higher level carrier) or in a multichip package (such as a ceramic carrier that has either or both surface interconnections or buried interconnections). In any case, the chip is then integrated with other chips, discrete circuit elements, and/or other signal processing devices as part of either (a) an intermediate product, such as a motherboard, or (b) an end product. The end product can be any product that includes integrated circuit chips, ranging from toys and other low-end applications to advanced computer products having a display, a keyboard or other input device, and a central processor. 
     It should also be understood that material compounds will be described in terms of listed elements, e.g., SiGe. These compounds include different proportions of the elements within the compound, e.g., SiGe includes Si x Ge 1-x  where x is less than or equal to 1, etc. In addition, other elements can be included in the compound and still function in accordance with the present embodiments. The compounds with additional elements will be referred to herein as alloys. Reference in the specification to “one embodiment” or “an embodiment” of the present invention, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment”, as well any other variations, appearing in various places throughout the specification are not necessarily all referring to the same embodiment. 
     It is to be appreciated that the use of any of the following “/”, “and/or”, and “at least one of”, for example, in the cases of “A/B”, “A and/or B” and “at least one of A and B”, is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of “A, B, and/or C” and “at least one of A, B, and C”, such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and. C). This can be extended, as readily apparent by one of ordinary skill in this and related arts, for as many items listed. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising.” “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof. 
     Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper,” and the like, can be used herein for ease of description to describe one element&#39;s or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the FIGS. It will be understood that 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 FIGS. For example, if the device in the FIGS. is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein can be interpreted accordingly. In addition, it will also be understood that when a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers can also be present. 
     It will be understood that, although the terms first, second, etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, a first element discussed below could be termed a second element without departing from the scope of the present concept. 
     Having described preferred embodiments for methods and devices for placement of a contact landing on a sacrificial fin with self-alignment capability (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments described which are within the scope of the invention as outlined by the appended claims. Having thus described aspects of the invention, with the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.