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 .
Response to Arguments
Applicant’s arguments with respect to claims presented have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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.
Claims 1, 8 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Basker et al. (US20190189769A1) in view of ZHU et al. (US20230187497A1).
Regarding claim 1, Fig.2 of Basker teaches a method for forming a field-effect transistor device, the method comprising: forming a fin structure comprising a layer stack comprising channel layers (para.0004, silicon layers 21) and non-channel layers (para.0004, silicon germanium layers 22) alternating the channel layers 21, wherein the channel layers 21 are of a channel material and the non-channel layers 22 are alternatingly first non-channel layers 22 of a first layer material and second non-channel layers 22 of a second layer material, and the fin structure comprising a first fin part, a second fin part and a third fin part intermediate the first and second fin parts (See annotated Fig.1B); forming a source body (para.0044, source/drain regions 38) and a drain body (para.0044, source/drain regions 38), each comprising a respective common body portion 29 (para.0044) along the first side and a set of prongs, (see annotated Fig.2C) protruding from the respective common body portion 29 into the source and drain cavities 36, respectively, and abutting the channel layers 21; forming a gate body comprising a common gate body portion (para.0044, extension regions 38, see annotated Fig.2C) along the second side and a set of gate prongs (see annotated Fig.2C) protruding from the common gate body portion 38 into the gate cavities 36.
Basker does not teach wherein while masking the fin structure from a second side of the fin structure opposite a first side of the fin structure: etching each of the first and second fin parts laterally from the first side such that a set of source cavities extending through the first fin part is formed in the first non- channel layers, and such that a set of drain cavities extending through the second fin part is formed in the first non- channel layers, and subsequently and while masking the fin structure from the first side: etching the third fin part laterally from the second side such that a set of gate cavities extending through the third fin part is formed in the second non- channel layers, and subsequently.
ZHU teaches, in Figs. 9-12, para.0062 and para.0064, wherein a masking layer, such as a photoresist 1043, may be formed to mask the first element region and the second element region, while exposing a region between them. The photoresist 1043 may be used as an etching mask to selectively etch the layers below in sequence. The protective layer 1043 may be left in the first element region and cover the side walls of the first active layers 1009 and 1013. In the second element region, the side walls of the first active layers 1009 and 1013 may be exposed through the trench T3. The first active layers 1009 and 1013 may be removed from the second element region by a selective etching, such as a wet etching with a TMAH solution, relative to the second active layers 1011 and 1015 (and the occupation layer 1005).
As shown in FIG. 11, in the second element region, the second active layers 1011 and 1015 (nanosheets) and the fourth active layer 1037 (especially its vertical portion, that is, the fin) form a comb-shaped structure.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use ZHU’s protective layer 1043, to enable etching one side of the fin at a time, in the teachings of Basker in order to improve the performance of the element, such as a suppression of short channel effect and also control an etching amount. (ZHU, [para.0065]).
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Regarding claim 8, Fig.2B of Basker teaches the method according to claim 1, wherein the source and drain cavities (para.0029, recesses 36, see annotated Fig.2B) are etched to extend partly into the third fin part and/or the gate cavities (para.0029, recesses 36, see annotated Fig.2B) are etched to extend partly into the first and second fin parts (see annotated Fig.2B).
Regarding claim 13, Fig.2B of Basker teaches the method according to claim 1, wherein forming the source and drain bodies comprises epitaxially growing a source/drain material in the set of source cavities (para.0029, recesses 36, see annotated Fig.2B) and the set of drain cavities (para.0029, recesses 36, see annotated Fig.2B) to form prongs (see annotated Fig.2C) therein, and further growing the source/drain material on the prongs 38 such that the source/drain material merges to form a respective common body portion 29 (para.0044) of the source and drain bodies.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Basker et al. (US20190189769A1) in view of ZHU et al. (US20230187497A1) and in further view of Chang et al. (US20120049268A1).
Regarding claim 2, Fig.2B of Basker teaches the method according to claim 1, Basker does not teach wherein the first layer material is a first dielectric material.
Chang teaches, in Fig.1, wherein the first layer (para.0029, interlayer dielectrics 120) material is a first dielectric material.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include the interlayer dielectrics of Chang in the invention of Basker in order to control the flow of current.
Claims 3-7,9-12 and 15-17 are rejected under 35 U.S.C. 103 as being unpatentable over Basker et al. (US20190189769A1) in view of Chang et al. (US20120049268A1) and in view of ZHU et al. (US20230187497A1) and in further view of Cheng et al. (US20200227305A1).
Regarding claim 3, Fig.2B of Basker teaches the method according to claim 2, wherein forming the fin structure comprises: forming a preliminary fin structure comprising the channel layers (para.0004, silicon layers 21) and non-channel layers (para.0004, silicon germanium layers 22) alternating the channel layers 21, the non- channel layers 22 being alternatingly sacrificial layers of a sacrificial semiconductor material and the second non-channel layers 22 of the second layer material.
Basker does not teach forming a support structure in abutment with the preliminary fin structure; and while the support structure supports the preliminary fin structure, replacing the sacrificial layers with the first non-channel layers.
Cheng, in Fig.6, teaches forming a support structure 602(para.0038) in abutment with the preliminary fin structure; and while the support structure 602 supports the preliminary fin structure, replacing the sacrificial layers with the first non-channel layers (para.0031, sacrificial layers 106).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to support structure of Cheng in the invention of Basker in order to provide support.
Regarding claim 4, Basker and Cheng teach teaches the method according to claim 2, further comprising, prior to forming the source and drain cavities (Basker, para.0029, recesses 36, see annotated Fig.2B): etching each of the first and second fin parts (see annotated Fig.2B) laterally from each of the first and second sides such that a set of cavities 36 extending through the first and second fin parts (see annotated Fig.2B) is formed in the second non-channel layers (para.0004, silicon germanium layers 22), and filling the cavities 36 with a second dielectric material (Cheng, Fig.9, para.0040, liner 902) to form second dielectric layers in the cavities 36.
Regarding claim 5, Fig.2B of Basker teaches the method according to claim 4, wherein the etching of the third fin part (see annotated Fig.2B) to form the gate cavities (para.0029, recesses 36, see annotated Fig.2B) comprises selectively etching the second layer material (para.0029, silicon layers 21) from the second side to remove the second layer material 21 remaining between the second dielectric layers.
Regarding claim 6, Basker and Cheng teach the method according to claim 3, further comprising, prior to forming the source and drain cavities (Basker, para.0029, recesses 36, see annotated Fig.2B): etching each of the first and second fin parts laterally from each of the first and second sides such that a set of cavities 36 extending through the first and second fin parts is formed in the second non-channel layers (Basker, Fig.2B, para.0029, silicon layers 21), and filling the cavities (Cheng, Fig.9, para.0039, indentations 802) with a second dielectric material (Cheng, Fig.9, para.0040, liner 902) to form second dielectric layers in the cavities 802.
Regarding claim 7, Fig.2B of Basker teaches the method according to claim 6, wherein the etching of the third fin part (see annotated Fig.2B) to form the gate cavities (para.0029, recesses 36, see annotated Fig.2B) comprises selectively etching the second layer material (para.0029, silicon layers 21) from the second side to remove the second layer material 21 remaining between the second dielectric layers.
Regarding claim 9, Cheng teaches, in Fig.13, the method according to claim 1, further comprising: depositing a cover material (Cheng, Fig.13, para.0045, cap 1304) along the first and second sides of the fin structure; and forming openings in the cover material 1304 along the first and second fin parts (see annotated Fig.13) to expose each of the first and second fin parts from only the first side; wherein the method subsequently comprises conducting said etching of the first and second fin parts (see annotated Fig.13) via said openings in the cover material 1304. The selectivity of etch to the fin can be achieved by using silicon nitride based hard mask at the top of the fins (to protect the fins during the etch); para.0041.
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Regarding claim 10, Cheng, in Fig.13, teaches the method according to claim 9, wherein the cover material (Fig.13, para.0045, cap 1306) is conformally deposited.
Regarding claim 11, Cheng, in Fig.13, teaches the method according to claim 1, further comprising forming a gate trench along the third fin part to expose the third fin part from only the second side, wherein the gate trench is formed in an insulating material (para.0049, liner layer 902) deposited along the first and second sides of the fin structure, wherein said etching of the third fin part and said forming of the gate body (see annotated Fig.13) are conducted via said gate trench. Gate trench is formed between nanosheet stacks 150 as shown in Fig.3.
Regarding claim 12, Cheng, in Fig.13, teaches the method according to claim 11, wherein said etching of the third fin part and said forming of the gate body (see annotated Fig.13) are conducted subsequent to forming the source and drain bodies 1104(Fig.13, para.0048), and wherein the method comprises depositing the insulating material (para.0049, liner layer 902) to embed the fin structure and the source and drain bodies 1104.
Regarding claim 15, Cheng, in Fig.13, teaches the method according to claim 14, wherein forming the set of source cavities (para.0039, indentations 802, see annotated Fig.8) and the set of drain cavities (para.0039, indentations 802) comprises selectively etching doped first layer material (para.0039, sacrificial layers 106) of the first and second fin parts (see annotated Fig.13).
Regarding claim 16, Cheng, in Fig.13, teaches the method according to claim 4, wherein forming the set of source cavities and the set of drain cavities (para.0039, indentations 802) comprises selectively etching doped first layer material (para.0039, sacrificial layers 106) of the first and second fin parts (see annotated Fig.13).
Regarding claim 17, Fig.2B of Basker teaches the method according to claim 16, wherein forming the cavities (para.0029, recesses 36, see annotated Fig.2B) comprises selectively etching doped second layer material (Fig.2B, para.0029, silicon layers 21) of the first and second fin parts (see annotated Fig.1B).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Basker et al (US20190189769A1) in view of ZHU et al. (US20230187497A1) and in further view of CHU et al (US20220115498A1).
Regarding claim 14, Fig.2B of Basker teaches the method according to claim 1,
Basker does not teach further comprising subjecting the first and second fin parts to an ion implantation process while masking the third fin part from the ion implantation process.
CHU, in paragraph 0052, teaches further comprising subjecting the first and second fin parts to an ion implantation process while masking the third fin part from the
ion implantation process. Using masks, an n-type impurity implant may be performed in p-type regions of the substrate 110, and a p-type impurity implant may be performed in n-type regions of the substrate 110.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include impurity implantation of CHU in the invention of Basker in order to provide doping and thus provide electrical conductivity.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VINCENT KIPKEMOI RONO whose telephone number is (571)270-5977. The examiner can normally be reached Mon-Fri, 8am-5pm.
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VINCENT KIPKEMOI. RONO
Examiner
Art Unit 2891
/V.K.R./Examiner, Art Unit 2891
/MATTHEW C LANDAU/Supervisory Patent Examiner, Art Unit 2891