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 .
Claim Rejections - 35 USC § 103
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 1-11, 14, 15, 17, 18 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Yeo et al (USPN 9,564,489) in view of Henson (USPN 8,946,721).
Regarding claim 1, Yeo et al disclose a method comprising:
forming a first source/drain feature 42 on a first fin 22 disposed on a substrate, wherein the first fin is at least partially embedded within a first isolation layer 24 [see Fig. 7B];
removing a portion of the first isolation layer such that the first isolation layer has a concave top surface defining a recess [see Fig. 7B];
forming an etch stop layer 46 within the recess on the concave top surface of the first isolation layer [see Fig. 8; see also col. 6, lines 32-35]; and
forming a second isolation layer 50 on the etch stop layer within the recess.
Yeo et al do not disclose performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first fin. One such as Henson disclose a substantially similar method comprising: forming a first source/drain feature 7, forming an etch stop layer 35; forming a second isolation layer 40 on the etch stop layer, and performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the channel [see Fig. 4; see also col. 10, lines 9-16 and lines 36-56]. It would have been obvious to one of ordinary skill in the art at the time of invention to include the second isolation layer, which has been treated to impart tensile stress, in the method of Yeo et al because Henson teaches that so doing allows tuning the carrier mobility in the channel of semiconductor devices [see col. 4, line 67 to col. 5, line 3]. Furthermore, whether the channel is approximately planar, as in Henson, or contained within a fin, as in Yeo et al, the stress-inducing layer has utility in increasing or decreasing the carrier mobility.
Regarding claim 2, the prior art of Yeo et al and Henson disclose the method of claim 1. Furthermore, Yeo et al disclose wherein the forming of the etch stop layer within the recess on the concave top surface of the first isolation layer includes forming the etch stop layer directly on the concave top surface of the first isolation layer [see Fig. 8; see also col. 6, lines 32-39].
Regarding claim 3, the prior art of Yeo et al and Henson disclose the method of claim 1. Furthermore, Yeo et al disclose wherein the forming of the etch stop layer within the recess on the concave top surface of the first isolation layer includes forming the etch stop layer directly on the first source/drain feature [see Fig. 8].
Regarding claim 4, the prior art of Yeo et al and Henson disclose the method of claim 1. Furthermore to the second isolation layer, Henson discloses wherein the forming of the second isolation layer on the etch stop layer within the recess includes forming the first isolation layer directly on the etch stop layer within the recess [see Fig. 4].
Regarding claim 5, the prior art of Yeo et al and Henson disclose the method of claim 4. Furthermore to the second isolation layer, Henson discloses wherein the forming of the second isolation layer on the etch stop layer within the recess includes forming the first isolation layer over the first source/drain feature such that the second isolation layer covers the first source/drain feature [see Fig. 4].
Regarding claim 6, the prior art of Yeo et al and Henson disclose the method of claim 1. The combination of Yeo et al and Henson would result in a structure whereby the first isolation layer (i.e. layer 24 of Yeo et al) has a different material composition than the second isolation layer (i.e. layer 40 of Henson) [see Yeo et al, col. 3, lines 21-23; see also Henson, col. 10, lines 25-27]. It would have been obvious to one of ordinary skill in the art to form the first and second isolation layers from different materials because the mechanism by which the stress is imparted requires it.
Regarding claim 7, the prior art of Yeo et al and Henson disclose the method of claim 1. Furthermore, Yeo et al disclose wherein the first source/drain feature includes an n-type dopant [see col. 5, lines 63-65].
Regarding claim 8, the prior art of Yeo et al and Henson disclose the method of claim 1. Furthermore to the second isolation layer, Henson discloses wherein the performing of the treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first fin includes applying an annealing process to the second isolation layer [see col. 10, lines 36-56, wherein rapid thermal deposition is used, which includes high temperatures].
Regarding claim 9, Yeo et al disclose a method comprising:
forming a first fin structure 22 and a second fin structure 22 disposed on a substrate, wherein a first isolation layer 24 extends from the first fin structure to the second fin structure[see Fig. 7B];
forming a recess within the first isolation layer between the first and second fin structures [see Fig. 7B]; and
forming a second isolation layer 50 within the recess and over the first and second fin structure.
Yeo et al do not disclose performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first and second fin structures. One such as Henson disclose a substantially similar method comprising: forming a first source/drain feature 7, forming an etch stop layer 35; forming a second isolation layer 40 on the etch stop layer, and performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the channel [see Fig. 4; see also col. 10, lines 9-16 and lines 36-56]. It would have been obvious to one of ordinary skill in the art at the time of invention to include the second isolation layer, which has been treated to impart tensile stress, in the method of Yeo et al because Henson teaches that so doing allows tuning the carrier mobility in the channel of semiconductor devices [see col. 4, line 67 to col. 5, line 3]. Furthermore, whether the channel is approximately planar, as in Henson, or contained within a fin, as in Yeo et al, the stress-inducing layer has utility in increasing or decreasing the carrier mobility.
Regarding claim 10, the prior art of Yeo et al and Henson disclose the method of claim 9. Furthermore, Yeo et al disclose comprising forming an etch stop layer 46 in the recess directly on the first isolation layer, and
wherein the etch stop layer prevents the second isolation layer from interfacing with the first isolation layer [see Fig. 8].
Regarding claim 11, the prior art of Yeo et al and Henson disclose the method of claim 9. Furthermore, Yeo et al disclose comprising a first source/drain feature on the first fin structure, and
wherein the second isolation layer extends to a greater height above the substrate than the first source/drain feature after the forming of the second isolation layer [see Fig. 8].
Regarding claim 14, the prior art of Yeo et al and Henson disclose the method of claim 9. Furthermore, Yeo et al disclose comprising forming a gate structure 74 on the first and second fin structures [see Fig. 17B; see also col. 9, lines 29-31].
Regarding claim 15, Yeo et al disclose a method comprising:
forming a first fin 22 on a substrate;
forming a shallow trench isolation structure 24 on the substrate, wherein the first fin is at least partially embedded in within the shallow trench isolation structure;
recessing the shallow trench isolation structure such that the recessed shallow trench isolation structure has a concave top surface defining a recess [see Fig. 6B]; and
forming an isolation layer within the recess 50 [see Fig. 8].
Yeo et al do not disclose performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first and second fin structures. One such as Henson disclose a substantially similar method comprising: forming a first source/drain feature 7, forming an etch stop layer 35; forming a second isolation layer 40 on the etch stop layer, and performing a treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the channel [see Fig. 4; see also col. 10, lines 9-16 and lines 36-56]. It would have been obvious to one of ordinary skill in the art at the time of invention to include the second isolation layer, which has been treated to impart tensile stress, in the method of Yeo et al because Henson teaches that so doing allows tuning the carrier mobility in the channel of semiconductor devices [see col. 4, line 67 to col. 5, line 3]. Furthermore, whether the channel is approximately planar, as in Henson, or contained within a fin, as in Yeo et al, the stress-inducing layer has utility in increasing or decreasing the carrier mobility.
Regarding claim 17, the prior art of Yeo et al and Henson disclose the method of claim 15. Furthermore to the treatment process, Henson discloses wherein the performing of the treatment process includes applying an annealing process to the isolation layer, and
wherein the annealing process is selected from the group consisting of a furnace annealing process, a rapid thermal annealing process, a spike annealing process and a laser annealing process. Henson discloses wherein the performing of the treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first fin includes applying an annealing process to the second isolation layer [see col. 10, lines 36-56, wherein rapid thermal deposition is used, which includes high temperatures].
Regarding claim 18, the prior art of Yeo et al and Henson disclose the method of claim 15. Furthermore to the treatment process, Henson discloses comprising forming a source/drain feature prior to the performing of the treatment process on the isolation layer. Furthermore, the combination with Yeo et al would result in the source/drain feature being formed on the first fin.
Regarding claim 20, the prior art of Yeo et al and Henson disclose the method of claim 15. Furthermore, Yeo et al disclose comprising forming a gate structure 74 on the first and second fin structures [see Fig. 17B; see also col. 9, lines 29-31].
Claims 12, 13 and 19 are rejected under 35 U.S.C. 103 as being unpatentable over Yeo et al (USPN 9,564,489) in view of Henson (USPN 8,946,721) as applied to claim 9 above, and further in view of Lim et al (USPN 6,297,126).
Regarding claims 12 and 13, Yeo et al and Henson disclose the method of claim 9. Neither Yeo et al nor Henson disclose specifically wherein the first isolation layer between the first and second fin structures includes performing a wet etching process or a dry etching process. One such as Lim et al disclose a substantially similar STI structure as that disclosed by Yeo et al, wherein the STI structure is recessed by using either a wet etch or a dry etch process [see col. 3, lines 36-42]. It would have been obvious to one of ordinary skill in the art at the time of invention to perform the recessing by the wet or dry etching processes of Lim et al because they are known in the art for the purpose. It has been held that simple substitution of one known process for another to obtain predictable results is obvious. See KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (2007). See MPEP 2143.
Regarding claim 19, Yeo et al and Henson disclose the method of claim 15. Neither Yeo et al nor Henson disclose specifically wherein the recessing of the shallow trench isolation structure includes anisotropically etching the shallow trench isolation structure. One such as Lim et al disclose a substantially similar STI structure as that disclosed by Yeo et al, wherein the STI structure is recessed by using either a wet etch (isotropic) or a dry etch (anisotropic) process [see col. 3, lines 36-42]. It would have been obvious to one of ordinary skill in the art at the time of invention to perform the recessing by the wet or dry etching processes of Lim et al because they are known in the art for the purpose. It has been held that simple substitution of one known process for another to obtain predictable results is obvious. See KSR International Co. v. Teleflex Inc., 82 USPQ2d 1385 (2007). See MPEP 2143.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Yeo et al (USPN 9,564,489) in view of Henson (USPN 8,946,721) as applied to claim 15 above, and further in view of Balsan et al (US Patent Application Publication 2002/0039835).
Regarding claim 16, Yeo et al and Henson disclose the method of claim 15. Neither Yeo et al nor Henson disclose specifically wherein performing of the treatment process includes annealing the isolation layer at a temperature ranging from about 500ºC to about 1200ºC. Henson discloses wherein the performing of the treatment process on the second isolation layer to thereby cause the second isolation layer to impart a tensile stress on the first fin includes applying an annealing process to the second isolation layer [see col. 10, lines 36-56, wherein rapid thermal deposition is used, which includes high temperatures]. One such as Balsan et al disclose rapid thermal deposition of Si3N4, which is exemplarily disclosed by Henson for the second isolation layer, at temperatures that overlap the claimed ranges [see paragraph 0052]. It would have been obvious to one of ordinary skill in the art at the time of invention to perform the RTCVD method of Henson at the claimed temperatures because they are known in the art for the purpose, as described by Balsan et al.
Conclusion
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/C.E.S./Examiner, Art Unit 2899 /VICTOR A MANDALA/Primary Examiner, Art Unit 2899
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