DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Information Disclosure Statement
The information disclosure statements (IDSs) submitted on 2/18/2025 and 5/13/2025 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
Specification
The disclosure is objected to because of the following informalities:
In paragraphs [0046], [0048]-[0050], and [0052]: “source region 106a” is mentioned at several locations in relation to Figure 1A, but “source region 106a” is not shown in any of the figures.
The label 127 is used for the label of both the “substrate” (see also the substrate in Figures 1A, 1C, 2A, 4A-F) and the “dopant”.
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
The title of the invention has been suggested as, “SILICIDE/GERMANOSILICIDE/GERMANIDE CONTACT FORMATION ON THE SOURCE AND DRAIN REGIONS BY USING A DOPED METAL CONTACT”.
Appropriate corrections are required.
Claim Objections
Claim 16 is objected to because of the following informalities:
In line 2 of claim 16, “the source and drain” should be changed to “the source and drain region”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 12-13 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 12, claim 12 recites the limitation “one or more metals” in lines 1-2. There is insufficient antecedent basis for this limitation neither in claim 12 nor in claim 1 which claim 12 depends on. For examining purpose, ““one or more metals” is considered as “the metal”, because “a metal” is introduced on line 5 of claim 1.
Regarding claim 13, claim 13 recites the limitation “the region” in line 2. There is insufficient antecedent basis for this limitation neither in claim 13 nor in claim 1 on which claim 13 depends. For examining purpose, “the region” is considered as “the region between at least a section of the source or drain region and the contact” which is introduced in claim 1.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 1-3, 5-8, and 10-16 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Liu-1 (US 2020/0006545 A1, embodiments for p-type devices, [0021]).
Regarding claim 1, Liu-1 teaches an integrated circuit structure (FinFET, Fig. 9, [0013] and [0055]), comprising:
a source or drain region (S/D structures 292, Fig. 9, [0055]);
a contact (conductive features 234, Fig. 9, [0055]) comprising conductive material ([0055]: “ … tungsten , cobalt , copper , ruthenium , aluminum , gold , silver , alloys thereof, …”);
a region (silicide layer 214, Fig. 9, [0054]) between at least a section (crystalline region 223 ([0053]) and first region 213 ([0043], Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), the region comprising a metal and one or more semiconductor materials ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”, and therefore the region comprises the metal Ti, and the semiconductors Si and Ge.); and
a first dopant (second species 898, [0053]: boron as p-dopant ([0056])) and implanted second species 898 ([0036])) within the source or drain region (Fig. 11: boron concentration is about 1017 atoms/c.c. in the second region 217 of the S/D structures 292 (Fig. 9, [0043])), and a second dopant (first species 896, Fig. 9, [0053]) within the region (silicide layer 214, Fig. 9) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), the first dopant (p-dopant ([0056]) and implanted second species 898 ([0036]), boron) elementally different from the second dopant ([0031]: for example, Gallium Ga).
Regarding claim 2, Liu-1 teaches the integrated circuit structure of claim 1, wherein the region (silicide layer 214, Fig. 9) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9) comprises one or more of silicide, germanide, and/or germanosilicide ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”) of the one or more metals ([0052]: Ti).
Regarding claim 3, Liu-1 teaches the integrated circuit structure of claim 1, wherein:
the first dopant (p-dopant and implanted second species 898, Fig. 9) is also within the region (silicide layer 214, Fig. 9) between the at least section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), wherein a concentration (concentration is shown in Fig. 11) of the first dopant (p-dopant and implanted second species 898, which are boron) within the region (silicide layer 214, Fig. 9) between at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9) is less than a concentration of the first dopant (p-dopant and implanted second species 898, which are boron) within the source or drain region (S/D structures 292, Fig. 9; Fig. 11: the concentration close to the surface (depth 0) is lower than the concentration at the boundary between the crystalline region 223 and first region 213, which comprise a section of the S/D structures 292).
Regarding claim 5, Liu-1 teaches the integrated circuit structure of claim 1, wherein:
the second dopant (first species 896, Fig. 9, [0053]) is also within the source or drain region (S/D structures 292, [0032]: “… the PAI process 231 may create a Gaussian distribution of the first species within the crystal lattice of the epitaxial source / drain structures 292 , with the peak or highest concentration of atoms being near the top surface 215 of the epitaxial source / drain structures 292, and a lower concentration deeper into the epitaxial source / drain structures 292.”, see also Fig. 12, which shows Germanium concentration which parallels the concentration of first species), wherein a concentration of the second dopant (first species 896) within the source or drain region (S/D structures 292) is less than a concentration of the second dopant (first species 896) within the region (silicide layer 214, Fig. 9) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9).
Regarding claim 6, Liu-1 teaches the integrated circuit structure of claim 1, wherein each of the first dopant (second species 898, [0058]: boron as p-dopant) and the second dopant (first species 896, [0031]: Galium Ga which is a p-dopant]) comprises a p-type dopant.
Regarding claim 7, Liu-1 teaches the integrated circuit structure of claim 1, wherein the first dopant (second species 898) comprises a p-type dopant ([0058]: boron as p-dopant), and the second dopant (first species 896) comprises neither a p-type dopant nor an n-type dopant ([0031]: “The first species to be implanted may be an electrically inactive species, such as silicon, germanium, carbon, nitrogen, xenon, argon, and/or other suitable electrically inactive species.”).
Regarding claim 8, Liu-1 teaches the integrated circuit structure of claim 1, wherein the first dopant (second species 898) comprises boron ([0058]: boron), and the second dopant (first species 896) comprises one or more of gallium ([0031]: Gallium Ga), indium, aluminum, or carbon.
Regarding claim 10, Liu-1 teaches the integrated circuit structure of claim 1, wherein the first dopant (second species 898) comprises an n-type dopant ([0036]: in some other embodiments of Lie, “In some cases, the second species may also include n-type dopants such as phosphorous, arsenic, antimony, etc.”), and the second dopant (first species 896) comprises neither a p-type dopant nor an n-type dopant ([0031]: “The first species to be implanted may be an electrically inactive species, such as silicon, germanium, carbon, nitrogen, xenon, argon, and/or other suitable electrically inactive species.”).
Regarding claim 11, Liu-1 teaches the integrated circuit structure of claim 1, wherein the first dopant (second species 898) comprises phosphorous ([0036]: “… , the second species may also include n-type dopants such as phosphorous...”), and the second dopant (first species 896) comprises one or more of arsenic, antimony, bismuth, tellurium, or carbon (“The first species to be implanted may be … carbon …”).
Regarding claim 12, Liu-1 teaches the integrated circuit structure of claim 1, wherein the one or more metals (the metal in the silicide layer 214, para. [0052]]) comprise one or more of titanium ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”), gadolinium, erbium, scandium, molybdenum, niobium, nickel, cobalt, tungsten, or iridium.
Regarding claim 13, Liu-1 teaches the integrated circuit structure of claim 1, wherein the source or drain region (S/D structures 292 labeled as first source or drain region in Illustrative Fig. 1 which is an annotated version of Fig. 9) is a first source or drain region (first source or drain region, Illustrative Fig. 1), the contact (conductive features 234 as first contact in Illustrative Fig. 1) is a first contact (first contact), the region (silicide layer 214 labeled as first region in Illustrative Fig. 1) is a first region (first region), and wherein the integrated circuit structure further comprises:
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a second source or drain region (second source or drain region);
a body (semiconductor substrate 270, [0014]) comprising semiconductor material ([0014]: “silicon or germanium”) extending from the first source or drain region to the second source or drain region (Illustrative Fig. 1: the region between the first source drain region and second drain region is filled by fins 274 which are extensions of the semiconductor substrate 270);
a second contact (second contact) coupled to the second source or drain region (second source or drain region); and
a second region (second region) comprising one or more additional metals and the one or more semiconductor materials (first and second regions are identical in composition in Liu-1, therefore ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”, and the second region comprises the metal Ti, and the semiconductors Si and Ge.), the second region (second region) between at least a section of the second source or drain region (crystalline region 223 and first region 213 in the second source or drain regions) and the second contact (second contact),
wherein the second source or drain region comprises (second source or drain region) the first dopant (first and second source or drain regions are identical in material composition, and therefore the first dopant, second species 898, is also in the second source or drain region), and the second region (second region) comprises the second dopant (the first and second regions are identical in material composition, and therefore the second dopant, first species 896, is also in the second region).
Regarding claim 14, Liu-1teaches an integrated circuit structure (FinFET, Fig. 9, [0013] and [0055]), comprising:
a source or drain region (S/D structures 292 comprising second region 217, first region 213, crystalline region 223 and bottom portion of the silicide layer 214, Fig. 9, [0052] and [0057]; the border between the bottom and top portions of the silicide layer 214 is defined as the depth where the concentration of the second species 898 (boron, third profile 1218) is peaked as shown with dashed lines between the top portion and the bottom portion in Illustrative Fig. 2 (an annotated version of Fig. 11));
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a contact (conductive features 234, [0055], Fig. 9) coupled to the source or drain region (S/D structures 292, Fig. 9);
a region (top portion of the silicide layer 214, Fig. 9), comprising one or more of silicide, germanide, and/or germanosilicide ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”), the region (top portion of the silicide layer 214, Fig. 9) between the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214, Fig. 9) and the contact (conductive features 234, Fig. 9), wherein a portion (bottom portion of the silicide layer 214, Fig. 9) of the source or drain region (second region 217, first region 213, crystalline region 223 and bottom potion of the silicide layer 214, Fig. 9) is at a distance that is at most 5 nanometers (nm) (bottom and top portions of the silicide layer 214 are next to each other, and within 5nm distance from each other, see top portion and bottom portion in Illustrative Fig. 2) from the region (top portion of the silicide layer, Fig. 9) comprising the one or more of silicide, germanide, and/or germanosilicide ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).”); and
a dopant (second species 898, [0053]: boron as p-dopant ([0056])) within the region (top portion of the silicide layer 214, see third profile 1218 in Illustrative Fig. 2 which shows boron concentration at different depths, [0065]) and within the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214, Fig. 9), wherein a concentration of the dopant (the concentration of second species 898, boron, near the surface (depth zero), which is smaller than 2*1021 atoms/cc, Illustrative Fig. 2) within the region (top portion of the silicide layer 214, which is labeled as top portion in Illustrative Fig. 2) is within 25% of a concentration of the dopant within the portion (the peak concentration in the bottom portion in Illustrative Fig. 2, which is larger than 2*1022 atoms/cc, meaning that a concentration of the dopant in the region is within 25% of a concentration in the bottom portion) of the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214, Fig. 9).
Regarding claim 15, Liu-1 teaches the integrated circuit structure of claim 14, wherein the concentration of the dopant (second species 898, boron) within the region (top portion, see third profile 1218 for the concentration in Illustrative Fig. 2) is within 10% of the concentration (close to the surface, which corresponds to the region, the concentration is smaller than 2*1021 atoms/cc whereas the peak concentration corresponding the bottom portion is larger than 2*1022 atoms/cc, which means that a concentration of the dopant in the region is within 10% ) of the dopant (second species 898, boron) within the portion of the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214).
Regarding claim 16, Liu-1 teaches the integrated circuit structure of claim 14, wherein the portion (bottom portion, Illustrative Fig. 2) is a first portion (bottom portion), wherein a second portion (second portion in Illustrative Fig. 2) of the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214, Fig. 9) is between 5 to 10 nm (0.8-1.1 nm) of the region (top portion), and wherein the concentration of the dopant (the concentration close to the surface, which is smaller than 2*1021 atoms/cc) within the region (top portion) is within 20% of a concentration of the dopant (the concentration of boron at the boundary of bottom portion and second portion, which is about 1*1022 atoms/cc, which means that a concentration of the dopant in the region is within 20%) within the second portion of the source or drain region (second region 217, first region 213, crystalline region 223, and bottom portion of the silicide layer 214).
Examiner notes that Liu-1 teaches claims 1-3, 5-8, and 10-16, but Yun-1 does not cover claim 9, as this claim includes two different n-type dopants. A rejection is being made over another embodiment of Liu, Liu-2 (US 2020/0006545 A1, embodiments for p-type devices, [0021]) for claims 1 and 9 so as to cover claims 1-3 and 5-16 in total.
Claims 1 and 9 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Liu-2 (US 2020/0006545 A1, embodiments for n-type devices, [0021]).
Regarding claim 1, Liu-2 teaches an integrated circuit structure (FinFET, Fig. 9, [0013] and [0055]), comprising:
a source or drain region (S/D structures 292, Fig. 9, [0055]);
a contact (conductive features 234, Fig. 9, [0055]) comprising conductive material ([0055]: “ … tungsten , cobalt , copper , ruthenium , aluminum , gold , silver , alloys thereof, …”);
a region (silicide layer 214, Fig. 9, [0054]) between at least a section (crystalline region 223 ([0053]) and first region 213 ([0043], Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), the region comprising a metal and one or more semiconductor materials ([0052]: “… the silicide layer 214 may be Ti silicide (TiSiGe).” For p-type devices. While material composition of n-type devices are not disclosed, a person of ordinary skill in the art would understand that the silicide region would include the metal material of the contact and the n-type semiconductor region which is disclosed as SiP or SiCP ([0020]); and
a first dopant (n-type dopant, [0020]: phosphorus P in SiP) within the source or drain region (S/D structures 292), and a second dopant (second species 898, Fig. 9, [0036]) within the region (silicide layer 214, Fig. 9) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), the first dopant (n-dopant, [0020]: phosphorus) elementally different from the second dopant (second species 898, [0036]: arsenic).
Regarding claim 9, Liu-2 teaches the integrated circuit structure of claim 1, wherein each of the first dopant (n-type dopant, [0020]: phosphorus) and the second dopant (second species 898, [0036]: arsenic) comprises an n-type dopant (both phosphorus and arsenic are n-type dopants).
Claims 17-20, 22, and 24 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Yun-1 (US 2011/0237058 A1, the method of Figs. 3A-D applied to the PMOS region, [0054]-[0066]).
Regarding claim 17, Yun-1 teaches a method (Figs. 3A-D, [0053]) for forming silicide, germanide, and/or germanosilicide (first metal silicide patterns 150a, Fig. 3D, [0060]) adjacent to a source or drain region (first source/drain regions 102, Fig. 3A-D, [0054]), the method comprising:
forming the source or drain region (first source/drain regions 102, Figs. 3A-B, [0054]-[0055]: “… first source/drain regions 102 are formed in the PMOS region.”), the source or drain region (first source/drain regions 102, Fig. 3B) covered by dielectric material (interlayer dielectric 120, Fig. 3B, [0055]);
forming a recess (first contact holes 130a, Fig. 3B, [0055]) within the dielectric material (interlayer dielectric 120, Fig. 3B), the recess (first contact holes 130a, Fig. 3B) landing on the source or drain region (first source/drain regions 102, Fig. 3B);
depositing metal (first metal patterns 140a, Fig. 3B, [0055]) within a bottom section (where the first source/drain regions 102 is) of the recess (first contact holes 130a, Fig. 3B) and adjacent to the source or drain region (first source/drain regions 102), wherein the metal (first metal patterns 140a, Fig. 3B) to be deposited is doped with one or more dopants (first dopant, [0056]: “The first metal patterns 140a may be formed of a cobalt pattern including a first dopant, e.g., boron (B).”); and
processing the metal and the source or drain region (first source/drain regions 102, Fig. 3D, [0060]: “… first and second metal silicide patterns 150a and 150b may be formed through a heat treatment process.”), to form the silicide (first metal silicide 150a, Fig. 3D, [0060]), germanide, and/or germanosilicide adjacent to the source or drain region (first source/drain regions 102, Fig. 3D).
Regarding claim 18, Yun-1 teaches the method of claim 17,
further comprising: forming a contact (first metal contact 164a, Fig. 3D, [0059]), such that the silicide (first metal silicide 150a, Fig. 3D), germanide, and/or germanosilicide is between the source or drain region (first source/drain regions 102, Fig. 3D) and the contact (first metal contact 164a, Fig. 3D).
Regarding claim 19, Yun-1 teaches the method of claim 17, wherein the one or more dopants (first dopant) within the metal (first metal patterns 140a) are first one or more dopants (first dopant), and the method further comprises:
prior to forming the recess (first contact holes 130a, Fig. 3B), doping at least a section of the source or drain region (first source/drain regions 102, Fig. 3B) with second one or more dopants (p-type dopants; in PMOS devices the source and drain regions are doped by p-type dopants.).
Regarding claim 20, Yun-1 teaches the method of claim 17, wherein prior to depositing the metal (first metal patterns 140a, Fig. 3B), the metal (first metal patterns 140a) to be deposited is doped with one or more of boron ([0056]: “The first metal patterns 140a may be formed of a cobalt pattern including a first dopant, e.g., boron (B).”), gallium, indium, aluminum, or carbon.
Regarding claim 22, Yun-1 teaches the method of claim 17, wherein a concentration of the one or more dopants (first dopants) within the metal (first metal patterns 140a) to be deposited is in the range of 1-20% by weight ([0031]: “The first metal patterns 140a may include at least one of cobalt (Co), nickel (Ni), lead (Pd) and platinum (Pt)“ and “An atomic percent of boron (B) may be, for example, in a range of from about 1 % to about 30%.”. Therefore, given that boron has a molecular weight of 10.81 g/mol and nickel is 58.69 g/mol, the dopant boron is within 0.18 % to about 5.5% by weight).
Therefore, the range of weight percentage of dopants provided by the prior art overlaps with the range of weight percentage of dopants provided in the claimed invention, and a prima facie case of obviousness exists (see MPEP 2144.05(I)), as the range of weight percentage of dopants can be optimized by routine experimentation to achieve contact resistance while maintaining a proper device performance (see MPEP 2144.05(II)). Therefore, the range of values provided does not hold an inventive subject matter.
Regarding claim 24, Yun-1 teaches the method of claim 17, wherein the source or drain region (first source/drain regions 102, Fig. 3D) comprises a p-type dopant (while it is not specified in Yun-1, in PMOS devices the source and drain regions are doped with p-type dopants), and the metal (first metal patterns 140a, Fig. 3D) comprises one or more of titanium, molybdenum, niobium, nickel, cobalt ([0031]: “The first metal patterns 140a may include at least one of cobalt (Co), …”), tungsten, or iridium.
Examiner notes that Yun-1 teaches claims 17-20, 22, and 24, but Yun-1 does not cover claim 21, as this claim includes another type of dopant. A rejection is being made over another embodiment of Yun, Yun-2 (US 2011/0237058 A1, the method of Fig. 3A-D applied to the NMOS region, [0054]-[0066]) for claims 17 and 21 so as to cover claims 17-22, and 24 in total.
Claims 17 and 21 are rejected under 35 U.S.C. 102(a)(1) and 102(a)(2) as being anticipated by Yun-2 (US 2011/0237058 A1, the method of Figs. 3A-D applied to the NMOS region, [0054]-[0066]).
Regarding claim 17, Yun-2 teaches a method (Figs. 3A-D, [0053]) for forming silicide, germanide, and/or germanosilicide (second metal silicide patterns 150b, Fig. 3D, [0060]) adjacent to a source or drain region (second source/drain regions 103, Figs. 3A-D, [0054]), the method comprising:
forming the source or drain region (second source/drain regions 103, Figs. 3A-B, [0054]-[0055]: “… second source/drain regions 103 are formed in the NMOS region.”), the source or drain region (second source/drain regions 102, Fig. 3C) covered by dielectric material (interlayer dielectric 120, Fig. 3C, [0057]);
forming a recess (second contact holes 130b, Fig. 3C, [0057]) within the dielectric material (interlayer dielectric 120, Fig. 3C), the recess (second contact holes 130b, Fig. 3C) landing on the source or drain region (second source/drain regions 103, Fig. 3C);
depositing metal (second metal patterns 140b, Fig. 3C, [0058]) within a bottom section (where the second source/drain regions 103 is) of the recess (second contact holes 130b, Fig. 3C) and adjacent to the source or drain region (second source/drain regions 103), wherein the metal (second metal patterns 140b, Fig. 3C) to be deposited is doped with one or more dopants (second dopant, [0058]: “The second metal patterns 140b may include a second dopant, e.g., phosphorus (P).”); and
processing the metal and the source or drain region (second source/drain regions 103, Fig. 3D, [0060]: “… first and second metal silicide patterns 150a and 150b may be formed through a heat treatment process.”), to form the silicide (second metal silicide 150b, Fig. 3D, [0060]), germanide, and/or germanosilicide adjacent to the source or drain region (second source/drain regions 103, Fig. 3D).
Regarding claim 21, Yun-2 teaches the method of claim 17, wherein prior to depositing the metal (second metal patterns 140b, Fig. 3C), the metal (second metal patterns 140b) to be deposited is doped with one or more of phosphorous ([0058]: “The second metal patterns 140b may include a second dopant, e.g., phosphorus (P).”), arsenic, antimony, bismuth, tellurium, or carbon.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Liu-1 (US 2020/0006545 A1, embodiments for p-type devices, [0021]) as applied to claim 1-3, 5-8, and 10-16 above.
Regarding claim 4, Liu-1 teaches the integrated circuit structure of claim 1, wherein:
the first dopant (p-dopant and implanted second species 898, Fig. 9) is also within the region (silicide layer 214, Fig. 9; the concentration of boron (second species) is finite close to the surface (depth zero)) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9), wherein a concentration (concentration is shown in Fig. 11) of the first dopant (p-dopant and implanted second species 898, which are boron) within the region (silicide layer 214, Fig. 9) between at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9) is less than a concentration of the first dopant (p-dopant and implanted second species 898, which are boron) within at least a portion (see the portion with high concentration shown in a rectangle in Illustrative Fig. 3, which is an annotated version of Fig. 11) of the source or drain region (S/D structures 292, Fig. 9; Illustrative Fig. 3), the portion (the portion with high concentration, Illustrative Fig. 3) of the source or drain region (S/D structures 292, Fig. 9) at a distance of at most 5 nanometers (nm) ([0021]: “… the first region 213 may have a vertical depth in a range from about 25 nm to about 30 nm, measuring from the top surface 215.”, which makes the distance of the portion with high concentration about 17.1-20.4 nm deep. Also, [0054]: “The silicide layer 214 may have a thickness in a range from 2 nm to about 20 nm.”, which leads to a maximum distance of 18.4 nm) from the region (silicide layer 214, Fig. 9) between the at least a section (crystalline region 223 and first region 213, Fig. 9) of the source or drain region (S/D structures 292, Fig. 9) and the contact (conductive features 234, Fig. 9).
Therefore, the distance range (<18.4 nm) provided by the prior art overlaps with the distance range (<5nm). However, the range is significantly larger in the prior art. However, Liu-1 also discloses that different concentrations profiles can be obtained by adjusting the implant parameters ([0033]) and annealing parameters ([0052] and [0061]). Therefore, the distance between the regions can be adjusted by routine experimentation to optimize the contact resistance and device performance (see MPEP 2144.05(II)). Therefore, the distance range provided does not hold an inventive subject matter.
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Claim 23 is rejected under 35 U.S.C. 103 as being unpatentable over Yun-2 (US 2011/0237058 A1, the method of Fig. 3A-D applied to the NMOS region, [0054]-[0066]) as applied to claim 17 and 21 above, and further in view of Cabral (US 2012/0009771 A1).
Regarding claim 23, while Yun-2 teaches the method of claim 17, wherein the source or drain region (second source/drain regions 103, Figs. 3A-B, [0054]-[0055]: “… second source/drain regions 103 are formed in the NMOS region.”) comprises an n-type dopant (the source/drain regions in an NMOS includes n-type dopants)
Yun -2 does not teach that the metal comprises one or more of titanium, gadolinium, erbium, scandium.
Cabral, on the other hand, teaches a method (Figs. 1-4, [0020] and Abstract) for formation of a silicide contact (silicide contact 301, Fig. 3, [0022]) between a metal layer (doped metal layer 203, Fig. 3, [0021]) and semiconductor material (contact 202, Figs. 1-3[0021]: “The contact 202 may be an n-type contact comprising an n-doped semiconductor material Such as Si in some embodiments, or a p-type contact comprising a p-doped semiconductor material Such as Si in other embodiments.”) by depositing a doped metal layer (doped metal layer 203, Figs. 1-3) over the semiconductor material (contact 202) and annealing ([0022]), wherein, for the making a silicide contact on an n-type semiconductor layer, the metal (doped metal layer 203) comprises one or more of titanium ([0026]: “…titanium doped with n-type dopants…”), gadolinium, erbium, scandium.
Doped titanium as disclosed by Cabral is an alternative to doped metals disclosed by Yun-2 ([0058]: ”… cobalt (Co), nickel (Ni), lead (Pd) and platinum (Pt) …” ). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention could have used titanium disclosed by Cabral instead of the metal materials disclosed by Yun-2 to obtain the predictable result of forming a silicide contact on an n-type source/drain region (see MPEP 2143(I)(B)). Thus, the combination of Yun-2 and Cabral meets all the limitations of claim 23.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Yun-1 (US 2011/0237058 A1, the method of Figs. 3A-D applied to the PMOS region, [0054]-[0066]) as applied to claim 17-20, 22, and 24 above, and further in view of Cabral (US 2012/0009771 A1).
Regarding claim 25, while Yun-1 teaches the method of claim 17,
Yun-1 does not teach that depositing the metal comprises depositing the metal using a sputtering process.
Cabral, on the other hand, teaches a method (Figs. 1-4, [0020] and Abstract) for formation of a silicide contact (silicide contact 301, Fig. 3, [0022]) between a metal layer (doped metal layer 203, Fig. 3, [0021]) and semiconductor material (contact 202, Figs. 1-3[0021]: “The contact 202 may be an n-type contact comprising an n-doped semiconductor material Such as Si in some embodiments, or a p-type contact comprising a p-doped semiconductor material Such as Si in other embodiments.”) by depositing a doped metal layer (doped metal layer 203, Figs. 1-3) over the semiconductor material (contact 202) and annealing ([0022]), wherein depositing the metal comprises depositing the metal using a sputtering process ([0020]: “A segregated interfacial dopant layer may be formed in a silicide contact by a silicide process using plated or sputtered metal doped with acceptor atoms, such as boron (B), aluminum (Al), gallium (Ga), or indium (In), for p-type junctions, or doped with donor atoms, such as arsenic (AS), phosphorus (P), or antimony (Sb) for n-type junctions.”).
As disclosed by Cabral, sputtering deposition of a doped metal layer for forming a silicide contact is a known alternative of electroplating the doped metal which is the method used in Yun-1 ([0030]). Therefore, a person of ordinary skill in the art before the effective filing date of the claimed invention could have substituted the electroplating process for the deposition in the method of Yun-1 with the puttering process disclosed by Cabral (see MPEP 2143(I)(B)). Thus, the combination of Yun-1 and Cabral meets the limitations of claim 25.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Yun (US 2008/0296696 A1) teaches a method for forming a silicide contact on source/drain regions by using a doped metal, which is relevant to all claims.
Hu (US Patent No. 6,426,291 B1) teaches a method for doping a semiconductor structure by using a doped metal, which is relevant to all claims.
Kleemeier (US 2016/0118305 A1) teaches a method for forming a silicide contact on source/drain regions which is relevant to claims 1-16.
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/ILKER NMN OZDEN/Examiner, Art Unit 2812
/William B Partridge/Supervisory Patent Examiner, Art Unit 2812