DETAILED ACTION
This Office action is in response to the Request for Continued Examination (RCE) and Amendment filed on 21 January 2026. Claims 1, 2, 5-16, 18, and 20-23 are pending in the application. Claims 3, 4, 17, and 19 have been cancelled.
This application is a divisional of application Serial No. 16/887,154, filed on 29 May 2020, now US Patent 11,935,793.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 21 January 2026 has been entered.
Claim Rejections - 35 USC § 112
In light of Applicant’s Amendment, the rejection of claim 21 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, has been withdrawn.
Claim Rejections - 35 USC § 102
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.
Claims 1, 5, and 6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Ma et al., US 2020/0105934, newly cited.
With respect to claim 1, Ma et al. disclose a device, shown in Fig. 12, comprising:
a semiconductor substrate 50;
a gate stack 60/72 at a top surface of the semiconductor substrate 50;
a source/drain region 82A-82E adjacent the gate stack 60/72,
wherein the source/drain region 82A-82E comprises a first epitaxy region 82A-82E comprising first impurities;
a first doped region 82A comprising arsenic in the first epitaxy region 82A-82E (see paragraphs [0036]-[0040]); and
a second doped region 82B comprising third impurities (phosphorus, see paragraphs [0041]-[0042]) in the first epitaxy region 82A-82E, wherein the arsenic of the first doped region has a lower formation enthalpy than the third impurities (phosphorus),
the first doped region 82A surrounding sides of the second doped region 82B such that the arsenic in the first doped region 82A extends from a top of the semiconductor substrate 50 to along sides of the second doped region 82B, as shown in Fig. 12, and
wherein the arsenic of the first doped region 82A extends from the top of the semiconductor substrate 50 to below the second doped region 82B, as shown in Fig. 12.
With respect to claim 5, in the device of Ma et al., the third impurities are phosphorus, see paragraphs [0041]-[0042].
With respect to claim 6, in the device of Ma et al., a concentration of the third impurities (phosphorus) in the second doped region 82B increases in a direction towards a top surface of the source/drain region (the top surface being 82E), as shown in Fig. 13.
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.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Ma et al., US 2020/0105934, newly cited, as applied to claim 1 above, further in view of Lin et al., US 2017/0084741, and Kuang et al., US 2015/0372142, both of record.
Ma et al. is applied as above. In the same field of endeavor, Lin et al. teach that the peak phosphorus doping concentration in a source/drain region can be greater than about 1×1022 atoms/cm3, see paragraph [0054]. By providing relatively heavy phosphorus doping in a phosphorus-doped epitaxial layer, a reduction of contact capacitance and an increase in channel mobility for an n-type Fin FET can be achieved, see paragraph [0046]. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that a concentration of third impurities (phosphorus) can be at least 1023 cm-3.
Although a source/drain contact 112is shown in Fig. 20B of Ma et al., Ma et al. fail to teach a source/drain contact extending into the second doped region. Kuang et al. disclose a source/drain contact extending into the second doped region of an epitaxial source/drain region, as shown in Fig. 1, thereby providing an improved electrical contact with an enlarged contact area and low resistance. In light of these advantages, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include a source/drain contact extending into the second doped region in the known device of Ma et al.
Allowable Subject Matter
Claims 8-16, 18, 20, and 21-23 are allowable over the prior art of record.
The following is a statement of reasons for the indication of allowable subject matter: With respect to claim 8, Roh et al. disclose a device, shown in Fig. 4, comprising:
a gate stack 120/130 at a top surface a semiconductor substrate 110, see paragraph [0019];
a source/drain region 200/205/210 adjacent the gate stack 120/130, wherein the source/drain region 200/205/210 comprises:
a first epitaxy region 210 comprising first impurities (arsenic and phosphorus);
a second epitaxy region 205 extending along sidewalls and below the first epitaxy region 210, as shown in Fig. 4,
the second epitaxy region 205 comprising second impurities (phosphorus) different from the first impurities (arsenic);
an arsenic-doped region 300 extending into the first epitaxy region 210; and
a phosphorus-doped region 305 extending into the first epitaxy region 210, as shown in Fig. 3. However, Roh et al. fails to teach or suggest that arsenic of the arsenic-doped region 300 extends along sides and below the phosphorus-doped region, as required in independent claim 8.
Claims 9-14 are allowable due to their dependency on independent claim 8.
With respect to claim 15, the closest prior art of record is Chen et al., US 2015/0206946, newly cited. However, since the arsenic-doped region is region 52 and the phosphorus-doped region is region 54 in the device of Chen et al, as shown in Fig. 5 of Chen et al., Chen et al. fail to teach or suggest that phosphorus of the phosphorus-doped region extends lower than the arsenic of the arsenic-doped region.
Claims 16, 18, and 20-23 are allowable due to their dependency on independent claim 15.
Claim 2 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: The closest prior art of record is Ma et al., as applied above in the rejection of independent claim 1. However, Ma et al. fail to teach or suggest the source/drain region further comprises a second epitaxy region surrounding the first epitaxy region, wherein the second epitaxy region comprises fourth impurities, and the fourth impurities are a different element than the first impurities.
Response to Arguments
Applicant’s arguments with respect to claims 1, 5, 6, and 7 have been considered but are moot in light of the new ground of rejection based on the newly-cited reference to Ma et al., US 2020/0105934.
Conclusion
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MARY A. WILCZEWSKI
Primary Examiner
Art Unit 2898
/MARY A WILCZEWSKI/Primary Examiner, Art Unit 2898