Notice of Pre-AIA or AIA Status
The present application is being examined under the pre-AIA first to invent provisions.
Response to Amendment
The following office action is in response to the amendment and remarks filed on 12/10/25.
Applicant’s amendment to claims 8 and 16 is acknowledged.
Claims 1-20 are pending and subject to examination at this time.
Response to Arguments
Regarding claims 8 and 16:
Applicant's arguments with respect to claims 8 and 16 have been considered but are moot in view of the new ground(s) of rejection.
Regarding claim 1:
Applicant's arguments filed 12/10/25 have been fully considered but they are not persuasive.
Applicant submits at page 7-
Therefore, at best, to achieve the results of Chu, one of ordinary skill in the art would need to perform the etching of Ye followed by the smoothing process of Chu. Such a modification would not reasonably teach or suggest the claim language “following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less.”
In response-
The relevant art cited on the PTO-892 dated 10/24/25 (and Interview Summary dated 10/24/25) is reproduced here.
The following prior art made of record and not relied upon is considered pertinent to applicant's disclosure. The prior art disclose plasma etching can achieve a roughness < 2 nm.
Ballif, US 20120186642 A1
[0058] Then the smoothing intermediate layer 8 is smoothed, down to a roughness of 1-30 nm, by mechanical polishing or plasma etching, so that the intermediate layer 8 is smooth enough...
Nishida, WO 2008081987 A1
Page 16, lines 1-5: Smoothing the optical functional film 17 by plasma etching changes a surface roughness Rrms from 10 nm or more in normal state to Rrms < 2 nm. It is preferable to change the surface roughness Rrms < 0.5 nm.
Ye’s etching process is a plasma etching process, para. [0018], [0069]. One of ordinary skill in the art would not have to perform a smoothing process of Chu after Ye’s etching process, because Ye’s plasma etching process can achieve a roughness less than 2 nm.
Applicant submits at pages 7-8-
To the extent that the Office attempts to assert that the modification of Ye is merely to reduce the thickness variation, Applicants note that Ye fails to even mention the thickness variation produced by the etching process of Ye.
In response-
Ye is silent regarding the thickness variation. Ye’s thickness variation may or may not be less than 2 nm following the selectively etching process. Chu discloses the claimed range and provides motivation for one of ordinary skill in the art practicing Ye’s invention to achieve a variation less than 2 nm.
Applicant submits at page 8-
Therefore, there is no basis to determine how significant of a modification of Ye is needed in order to reach the thickness variation recited in claim 1. Since there is no way to determine what the modification to Ye would be; there is also no way to reasonably determine whether that modification to Ye would be considered obvious to one of ordinary skill in the art.
In response-
Applicant’s arguments are not clear here. A response is being provided to the best understanding of the argument.
The modification of Ye to achieve the thickness variation is considered obvious to one of ordinary skill in the art because the relevant art references discussed above disclose a plasma etching process can achieve a roughness less than 2 nm. If a plasma etching process can achieve a roughness less than 2 nm and Ye’s etching process is a plasma etching process, then it is not convincing that the modification is so “significant”, as characterized by the Applicant.
Applicant submits at page 8-
Applicants note that MPEP 2144.05 states “One factor that may weigh against maintaining an obviousness rejection based on optimization of a variable disclosed in a range in the prior art is where an applicant establishes that the prior art disclosure of the variable is within a range that is so broad in light of the dissimilar characteristics of the members of the range as to not invite optimization by one of skill in the art.”
Ye includes etchant flow rates of 50 sccm to 5000 sccm; etching pressure of 0.1 Torr to 150 Torr; and etching temperatures of 500 °C to 600 °C. (Ye at paragraphs 0041-0042). Even assuming that only integer values are used for each of the variables in Ye, there are over 74 million combinations of the variables…
In response-
Referring to the MPEP citation of “…based on optimization of a variable disclosed in a range”, the variable being optimized in claim 1 is the thickness variation. The variable in claim 1 is not flow rates, pressure or temperatures. One of ordinary skill in the art is not optimizing the flow rate, pressure or temperature in claim 1, as asserted by the Applicant.
Ye is silent regarding the thickness variation. Ye’s thickness variation may or may not be less than 2 nm. One of ordinary skill in the art practicing Ye’s invention would optimize the thickness variation to be less than 2 nm because Chu teaches a roughness of < 0.5 nm is “suitable for microelectronic applications”.
Applicant submits at page 8-
To the extent that the Office attempts to assert that Chu processes are compatible with the plasma etching of Ye, Applicants respectfully traverse such an assertion…Therefore, the processes explicitly described by Chu would be recognized as substantially different from the plasma etching of Ye.
In response-
The 35 USC 103 rejection does not apply Chu’s processes (e.g. GCIB or CMP) to Ye.
As discussed above, the relevant art cited disclose a plasma etching process can achieve a roughness less than 2 nm. Therefore, Ye’s plasma etching process can achieve a roughness less than 2 nm.
Claim Objections
Claim 8 is objected to because of the following informalities:
In claim 8, line 6, adding a comma after the word “region” will help with clarity of the claim language. For example, “…the region, the silicon germanium film…”
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 16-20 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
In claim 16, there does not appear to be support in the original specification for the limitation “wherein the first region is over the second region, and the first region has a different dopant concentration than the second region”.
For the prosecution record, please indicate where support can be found for this limitation.
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.
Claims 8-15 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.
In clam 8, line 4, there is insufficient antecedent basis for “the silicon germanium layer and the silicon layer”
Claim Rejections - 35 USC § 103
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-7 is/are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Ye et al., US Publication No. 2011/0124169 (of record) in view of Kim et al., US Publication No. 2007/0072399 A1 (of record) and Chu, US Publication No. 2004/0178406 A1 (of record).
Ye teaches:
1. A method comprising (see figs. 3-4):
selectively etching (218) a region (e.g. source/drain region 412/420) of a substrate using a germanium-containing gas (e.g. GeH4, see etchants at para. [0038] - [0040]), wherein the region of the substrate consists of Si and another material (e.g. see Si and Ge at para. [0025])…
wherein the region has a structure (e.g. source/drain structure 420)…, and the structure is in a recess (412) in the substrate. See Ye at para. [0048] – [0059], also see para. [0001] – [0071], figs. 1-5.
Ye does not expressly teach:
“wherein the region of the substrate consists of Si and another material, the other material consists of SiGe” such that “the region has a laminated structure of a SiGe film over a Si film”.
In an analogous art, Kim teaches:
“wherein a region (e.g. source/drain region, 120) of a substrate consists of Si (120a) and another material, the other material consists of SiGe (120b)” such that “the region has a laminated structure of a SiGe film (120b) over a Si film (120a)” See Kim at para. [0042] – [0043], figs. 3.
One of ordinary skill in the art modifying Ye with Kim would form “the region has a laminated structure having a SiGe film over a Si film, and the laminated structure is in a recess in the substrate”, as recited the claim, because Ye’s source/drain region is in a recess (412).
Ye does not expressly teach “…following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less”.
In an analogous art, Chu teaches etching SiGe (140a) to have a thickness variation of 2 nanometers (nm) or less (e.g. RMS of 0.5 nm), para. [0087], fig. 11.
It would have been obvious to one of ordinary skill in the art that to perform “…following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less” Chu teaches a source roughness < 0.5 nm is “suitable for microelectronics applications”. See Chu at para. [0016].
Kim further teaches:
2. The method of claim 1, further comprising:
depositing a silicon layer (120a); and
depositing a silicon germanium layer *(120b) over the silicon layer, wherein the silicon layer and the silicon germanium layer define the region (e.g. source/drain region), para. [0042] – [0043].
Regarding claim 3:
Ye teaches epitaxial growth at para. [0059].
Kim further teaches:
3. The method of claim 2, wherein depositing the silicon layer comprises epitaxially growing the silicon layer, para. [0042] – [0043].
Regarding claim 4:
Ye teaches epitaxial growth at para. [0059].
Kim further teaches:
4. The method of claim 2, wherein depositing the silicon germanium layer comprises epitaxially growing the silicon germanium layer, para. [0042] – [0043].
Regarding claim 5:
Ye further teaches:
5. The method of claim 1, wherein the germanium-containing gas comprises germanium hydride, para. [0040].
In regards to the limitation, “following the selectively etching a thickness of the region has a uniform thickness”, Chu teaches this limitation as applied to claim 1 above.
Regarding claim 6:
Ye further teaches:
6. The method of claim 1, wherein selectively etching the region comprises selectively etching the region at a temperature of 750°C or less, para. [0042].
Regarding claim 7:
Ye further teaches:
7. The method of claim 1, wherein selectively etching the region comprises selectively etching the region at a pressure ranging from about 50 Torr to about 500 Torr, para. [0042].
Claims 8-15 is/are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Ye et al., US Publication No. 2011/0124169 (of record) in view of Kim et al., US Publication No. 2007/0072399 A1 (of record), Chu, US Publication No. 2004/0178406 A1 (of record) and Murthy et al., US Publication No. 2011/0147828 A1.
Ye teaches:
8. A method comprising (see figs. 3-4):
(e.g. step 306) depositing films (e.g. see materials Si and Ge at para. [0025])…, wherein the films define a region (e.g. source/drain region 412/420);
(e.g. step 308) selectively etching (218) the region using a germanium-containing gas (e.g. GeH4, see etchants at para. [0038] - [0040])…
(e.g. step 310) repeating the depositing the films, and the selective etching to form a layer stack,
Ye does not expressly teach:
depositing a silicon germanium film over an entirety of the silicon film, wherein the silicon germanium layer and the silicon layer define a region;
In an analogous art, Kim teaches:
(see fig. 3) depositing a silicon film (120a);
depositing a silicon germanium film (120b) over an entirety of the silicon film (120a), wherein the silicon germanium layer and the silicon layer define a region (e.g. source/drain region, 120). See Kim at para. [0042] – [0043],
Ye does not expressly teach:
wherein following the selectively etching the region the silicon germanium film has a thickness variation of 2 nanometers (nm) or less;
In an analogous art, Chu teaches etching SiGe (140a) to have a thickness variation of 2 nanometers (nm) or less (e.g. RMS of 0.5 nm), para. [0087], fig. 11.
It would have been obvious to one of ordinary skill in the art that to perform “…following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less” Chu teaches a source roughness < 0.5 nm is “suitable for microelectronics applications”. See Chu at para. [0016].
Ye does not expressly teach:
wherein a top most layer of the layer stack has a different thickness profile from any other layer of the layer stack
In an analogous art, Murthy teaches:
(see figs. 6F and 14) wherein a top most layer (541, 542) of the layer stack (531/541, 532/542) has a different thickness profile from any other layer of the layer stack. See Murthy at para. [0065] – [0075], [0100].
Regarding claim 9:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 2 above.
Regarding claim 10:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 3 above.
Regarding claim 11:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 4 above.
Regarding claim 12:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 5 above.
Regarding claim 13:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 6 above.
Regarding claim 14:
Ye, Kim, Chu and Wang teach the limitations as applied to claim 7 above.
Regarding claim 15:
Ye teaches an iterative process to form the material in the source/drain region. Thus, Ye teaches (see fig. 3) “further comprising depositing material (step 310)…following the etching of the region (step 308)”.
Ye does not expressly teach depositing a silicon-containing material over the silicon germanium film.
Kim teaches forming a plurality of silicon (120a) and silicon-germanium film (120b) in fig. 3. Thus Kim teaches “further comprising depositing a silicon-containing material (e.g. upper 120a) over the silicon germanium film (e.g. lower 120b).
It would have been obvious to a person of ordinary skill in the art before the effective filling date of the claimed invention to modify the teachings of Ye with the teachings of Kim because “..when silicon layers having high growth speed in both the vertical and lateral directions and silicon germanium layers that exhibit diagonal growth are alternately stacked, a multi-layer epitaxial layer of the desired height may be grown that has suppressed lateral growth.” See Kim at para. [0043]. Furthermore, it is within the general skill of a worker in the art to select known material on the basis of its suitability for the intended purpose as a matter of obvious design choice. In re Leshin, 125 USPQ 416. See MPEP § 2144.07, Art Recognized Suitability for an Intended Purpose.
It would have been obvious to one of ordinary skill in the art that to perform “…following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less” Chu teaches a source roughness < 0.5 nm is “suitable for microelectronics applications”. See Chu at para. [0016].
It would have been obvious to a person of ordinary skill in the art before the effective filling date of the claimed invention to modify the teachings of Ye with the teachings of Murthy … “provide an advantage of inducing…stress on the channel region of the semiconductor… which increases the electron mobility and improves the device performance”. See Murthy at para. [0101].
Claims 16-20 is/are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Ye et al., US Publication No. 2011/0124169 (of record) in view of Wang et al., US Publication No. 2005/0095799 A1, Kim et al., US Publication No. 2007/0072399 A1 (of record) and Chu, US Publication No. 2004/0178406 A1 (of record).
Ye teaches:
16 A method comprising (see figs. 3-4):
(e.g. step 304) etching through a first region of a substrate (404)…to form a recess (412)…;
(e.g. step 306, 310) epitaxially growing a second layer over a first layer in the recess (e.g. materials for the epitaxial layers are Si and Ge at para. [0025]);
(e.g. step 308, 310) selectively etching (218) a region (e.g. source/drain region 412/420) of the substrate using a germanium containing gas (e.g. GeH4, see etchants at para. [0038] - [0040]),… See Ye at para. [0048] – [0059], also see para. [0001] – [0071], figs. 1-5.
Ye does not expressly teach:
etching through…a second region of the substrate to form a recess, wherein the first region is over the second region, and the first region has a different dopant concentration than the second region;
In an analogous art, Wang teaches:
(see figs. 1-3) etching through a first region (7, e.g. heavily doped source/drain) of a substrate (1) and a second region (4, e.g. LDD) of the substrate to form a recess (8a), wherein the first region (7) is over the second region (4), and the first region (e.g. heavily doped) has a different dopant concentration than the second region (e.g. LDD is lightly doped). See Wang at para. [0013] – [0018].
Ye does not expressly teach:
epitaxially growing a silicon germanium layer over a silicon layer in the recess;
wherein the silicon germanium layer and the silicon layer are laminated alternately,
In an analogous art, Kim teaches:
(see fig. 3) epitaxially growing a silicon germanium layer (120b) over a silicon layer (120a);
wherein the silicon germanium layer (120b) and the silicon layer (120a) are laminated alternately, para. [0042] – [0043], figs. 3.
One of ordinary skill in the art modifying Ye with Kim would form “epitaxially growing a silicon germanium layer over a silicon layer in the recess”, as recited the claim, because Ye’s source/drain region is in a recess (412).
Ye does not expressly teach:
following the selectively etching the region the silicon germanium film has a thickness variation of 2 nanometers (nm) or less.
In an analogous art, Chu teaches etching SiGe (140a) to have a thickness variation of 2 nanometers (nm) or less (e.g. RMS of 0.5 nm), para. [0087], fig. 11.
Regarding claim 16:
Ye, Wang, Kim and Chu teach the limitations as applied to claims 1 and 3-4 above.
Regarding claim 17:
Ye, Wang, Kim and Chu teach the limitations as applied to claim 5 above.
Regarding claim 18:
Ye, Wang, Kim and Chu teach the limitations as applied to claim 6 above.
Regarding claim 19:
Ye, Wang, Kim and Chu teach the limitations as applied to claim 7 above.
Regarding claim 20:
Ye, Wang, Kim and Chu teach the limitations as applied to claim 15 above.
It would have been obvious to a person of ordinary skill in the art before the effective filling date of the claimed invention to modify the teachings of Ye with the teachings of Wang to “…reduce source/drain resistance and to bury the damaged surface”. See Wang at para. [0017].
It would have been obvious to a person of ordinary skill in the art before the effective filling date of the claimed invention to modify the teachings of Ye with the teachings of Kim because “..when silicon layers having high growth speed in both the vertical and lateral directions and silicon germanium layers that exhibit diagonal growth are alternately stacked, a multi-layer epitaxial layer of the desired height may be grown that has suppressed lateral growth.” See Kim at para. [0043]. Furthermore, it is within the general skill of a worker in the art to select known material on the basis of its suitability for the intended purpose as a matter of obvious design choice. In re Leshin, 125 USPQ 416. See MPEP § 2144.07, Art Recognized Suitability for an Intended Purpose.
It would have been obvious to one of ordinary skill in the art that to perform “…following the selectively etching the region the SiGe has a thickness variation of 2 nanometers (nm) or less” Chu teaches a source roughness < 0.5 nm is “suitable for microelectronics applications”. See Chu at para. [0016].
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.
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 Michele Fan whose telephone number is 571-270-7401. The examiner can normally be reached on M-F from 7:30 am to 4 pm.
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/Michele Fan/
Primary Examiner, Art Unit 2818
23 February 2026