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 .
Election/Restrictions
Applicant’s election without traverse of Species I Fig 22A-22B in the reply filed on 2/3/2026 is acknowledged.
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 1-3, 5-8 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (US Patent No. 9,899,441) in view of Tang et al (US Publication No. 2023/0253207).
Regarding claim 1, Cheng discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 4, 108 having a recess Fig 4; and growing an epitaxial feature in the recess (Column 9, lines 7-44), wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 6, 118;(b) selectively etching the sub-layer of the epitaxial feature (Column 10, line 52-Column 12, line 2); and(c) repeating step (a) and step (b) alternately multiple times (Column 12, lines 35-53). Cheng discloses all the limitations but silent on the UV radiation. Whereas Tang discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 2, 12 having a recess Fig 2; and growing an epitaxial feature in the recess, wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 3;(b) selectively etching the sub-layer of the epitaxial feature while providing a first UV radiation Fig 4 ¶0028, 0033-0039. Cheng and Tang are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Cheng because they are from the same field of endeavor. Therefore, it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the process of Cheng and incorporate the teachings of Tang to improve manufacturing process and film uniformity ¶0002.
Regarding claim 2, Tang discloses wherein the first UV radiation is provided at a direction normal to a top surface of the substrate Fig 4.
Regarding claim 3, Cheng discloses wherein an upper portion of the sub-layer of the epitaxial feature is etched more than a lower portion of the sub- layer of the epitaxial feature in step (b) (Column 12, lines 35-53).
Regarding claim 5, Cheng in view of Tang discloses wherein the growing further comprises:(d) selectively growing the epitaxial feature in a z-direction while providing a second UV radiation after step (c) (Column 12, lines 35-53).
Regarding claim 6, Tang discloses wherein the second UV radiation is provided at a direction normal to a top surface of the substrate Fig 4.
Regarding claim 7, Cheng discloses wherein after step (d), a top width of the epitaxial feature is substantially equal to or greater than a bottom width of the epitaxial feature Fig 3A.
Regarding claim 8, Cheng discloses forming a liner layer between the substrate and the epitaxial feature Fig 3A.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al (US Patent No. 9,899,441) in view of Tang et al (US Publication No. 2023/0253207) and in further view of Huang (US Publication No. 2019/0371898).
Regarding claim 4, Cheng discloses all the limitations but silent on the shape of the epitaxial structure. Whereas Huang discloses wherein after step (c), a top width of the epitaxial feature is less than a bottom width of the epitaxial feature Fig 14. Cheng and Huang are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Cheng because they are from the same field of endeavor. Therefore, it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the shape of the source and drain of Cheng and incorporate the teachings of Huang since such a modification would have involved a mere change in the shape of a component. A change in shape is generally recognized as being within the level of ordinary skill in the art. In reDailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (US Patent No. 11,211,452) in view of Tang et al (US Publication No. 2023/0253207).
Regarding claim 9, Xie discloses a method of forming a semiconductor device, comprising: forming a semiconductor stack on a substrate Fig 1, wherein the semiconductor stack comprises first layers and second layers stacked alternately Fig 1; patterning the semiconductor stack and the substrate to form semiconductor strips Fig 1; forming insulating regions in lower portions of trenches between the semiconductor strips Fig 1-2; forming a first dummy gate stack and a second dummy gate stack across the insulating regions and the semiconductor strips Fig 2; removing portions of the semiconductor strips at opposite sides of each of the first dummy gate stack and the second dummy gate stack to form recesses exposing the substrate Fig 3; and forming an epitaxial feature from each of the recesses Fig 8. Xie discloses all the limitations but silent on the deposition process. Whereas Tang discloses performing a cyclic deposition and etching process with UV illumination Fig 2-4 ¶0034-0039. Xie and Tang are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Xie because they are from the same field of endeavor. Therefore it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the process of Xie and incorporate the teachings of Tang as an alternative process to improve manufacturing process and film uniformity ¶0002.
Claims 10-20 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al (US Patent No. 11,211,452) in view of Tang et al (US Publication No. 2023/0253207) and in further view of Cheng et al (US Patent No. 9,899,441).
Regarding claim 10, While Tang discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 2, 12 having a recess Fig 2; and growing an epitaxial feature in the recess, wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 3;(b) selectively etching the sub-layer of the epitaxial feature while providing a first UV radiation Fig 4 ¶0028, 0033-0039. Xie and Tang are silent on the frequency. Whereas Cheng discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 4, 108 having a recess Fig 4; and growing an epitaxial feature in the recess (Column 9, lines 7-44), wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 6, 118;(b) selectively etching the sub-layer of the epitaxial feature (Column 10, line 52-Column 12, line 2); and(c) repeating step (a) and step (b) alternately multiple times (Column 12, lines 35-53). Xie and Cheng are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Xie because they are from the same field of endeavor. Therefore it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the process of Xie and incorporate the teachings of Cheng to improve manufacturing process and film uniformity.
Regarding claims 11 and 15, Tang discloses the UV radiation but silent on the ranges. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the UV radiation ranges, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233 (1955).
Regarding claim 12, Cheng in view of Tang discloses wherein the growing further comprises:(d) selectively growing the epitaxial feature in a z-direction while providing a second UV radiation after step (c) (Column 12, lines 35-53).
Regarding claim 13, Tang discloses wherein the second UV radiation is different from the first UV radiation ¶0058-0060.
Regarding claim 14, Tang discloses wherein the second UV radiation is the same as the first UV radiation¶0058-0060.
Regarding claim 16, Cheng in view of Tang discloses wherein a cycle of the cyclic deposition and etching process comprises: (a) growing a sub-layer of the epitaxial feature in each of the recesses with a first UV power; (b) selectively etching the sub-layer of the epitaxial feature while providing a second UV power different from the first UV power; and (c) repeating step (a) and step (b) alternately multiple times, until each of the recesses is filled with the sub-layers Cheng-(Column 12, lines 35-53); Tang ¶0048-0064.
Regarding claim 17, Tang discloses wherein the first UV power ranges from zero to 10 W/m2, and second UV power ranges from 10 W/m2 to 10,000 W/m2 ¶0058-0059.
Regarding claim 18, Xie discloses removing the first dummy gate stack and the second dummy gate stack; performing an etching process to remove the first layers and therefore form gaps between the second layers; forming a gate dielectric layer wrapping the second layers; and forming a gate electrode to cover the gate dielectric layer Fig 3-5.
Regarding claim 19, Xie discloses a method of forming a semiconductor device, comprising: forming semiconductor strips on a substrate Fig 1; forming a dummy gate stack across the semiconductor strips Fig 2; removing portions of the semiconductor strips at opposite sides of the dummy gate stack to form recesses exposing the substrate forming an epitaxial feature in each of the recesses Fig 3-4, wherein the forming comprises:(a) growing a sub-layer of the epitaxial layer in each of the recesses Fig 7-8. Xie discloses all the limitations but silent on the deposition process with UV radiation. Whereas Tang discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 2, 12 having a recess Fig 2; and growing an epitaxial feature in the recess, wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 3;(b) selectively etching the sub-layer of the epitaxial feature while providing a first UV radiation Fig 4 ¶0028, 0033-0039. Xie and Tang are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Xie because they are from the same field of endeavor. Therefore it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the process of Xie and incorporate the teachings of Tang as an alternative process to improve manufacturing process and film uniformity ¶0002. Xie and Tang are silent on the frequency. Whereas Cheng discloses a method of forming a semiconductor device, comprising: providing a substrate Fig 4, 108 having a recess Fig 4; and growing an epitaxial feature in the recess (Column 9, lines 7-44), wherein the growing comprises:(a) growing a sub-layer of the epitaxial feature Fig 6, 118;(b) selectively etching/removing the sub-layer of the epitaxial feature (Column 10, line 52-Column 12, line 2); and(c) repeating step (a) and step (b) alternately multiple times until each of the recesses is filled with the sub-layers (Column 12, lines 35-53). Xie and Cheng are analogous art because they are directed to semiconductor devices having epi source and drain regions and one of ordinary skill in the art would have had a reasonable expectation of success to modify Xie because they are from the same field of endeavor. Therefore it would have been obvious to one having ordinary skill of the art before the effective filing date of the claimed invention to modify the process of Xie and incorporate the teachings of Cheng to improve manufacturing process.
Regarding claim 20, Cheng in view of Tang discloses wherein the growing further comprises:(d) selectively growing the epitaxial feature in a z-direction while providing a second UV radiation after step (c) (Column 12, lines 35-53).
Conclusion
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/CHRISTINE A ENAD/Primary Examiner, Art Unit 2811