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
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 1-6 are rejected under 35 U.S.C. 103 as being unpatentable over Cheng et al. (U.S. Publication No. 2022/0254776) in view of Peng et al. (U.S. Publication No. 2016/0181245).
Regarding claim 1, Cheng teaches a gate-all-around (GAA) transistor, comprising:
a semiconductor substrate (Fig. 31 and 33, substrate 202, labeled in Fig. 31);
an active structure (active structure 500) disposed on the semiconductor substrate, wherein the active structure comprises a source (240), a drain (also labeled 240), and a channel (channel 2080, labeled in Fig. 31) between the source and the drain (Fig. 33);
a doped structure (doped structure 206) inlaid in the semiconductor substrate (Fig. 33), wherein primary carriers of the doped epitaxial structure are opposite in polarity to primary carriers of the source and the drain (paragraph [0015]), and the doped epitaxial structure is disposed beneath the channel and not beneath the source and the drain (Fig. 33); and
a gate stack structure (gate stack 256, labeled in Fig. 31) surrounding the channel, wherein a portion of the gate stack structure beneath the channel is disposed between the doped epitaxial structure and the channel (Fig. 31 and 33).
Cheng does not teach that the doped structure is epitaxial. However, Peng teaches that instead of the implantation method of Cheng, a doped epitaxial anti punch-through can be formed (Peng Fig. 5A-D, epitaxial APT 512). It would have been obvious to a person of skill in the art at the time of the effective filing date that the implanted APT layer of Cheng could have been replaced by a doped epitaxial APT layer because Peng teaches that this allows for more customization in the material of the APT layer, such as thickness and material (Peng paragraph [0052]).
Regarding claim 2, Cheng in view of Peng teaches the GAA transistor according to claim 1, wherein a thickness of the doped epitaxial structure ranges from 10nm to 40nm (Peng paragraph [0052], 10nm).
Regarding claim 3, Cheng in view of Peng teaches the GAA transistor according to claim 1, wherein a concentration of dopants in the doped epitaxial structure is greater than a concentration of dopants in a portion of the semiconductor substrate in contact with the source and a portion of the semiconductor substrate in contact with the drain (Cheng paragraph [0015] and Peng paragraph [0022]).
Regarding claim 4, Cheng in view of Peng teaches the GAA transistor according to claim 1, wherein a concentration of dopants in the doped epitaxial structure ranges from 1x1018cm-3 to 1x1019cm-3 (Peng paragraph [0052]).
Regarding claim 5, Cheng in view of Peng teaches the GAA transistor according to claim 1, wherein a material of a matrix of the doped epitaxial structure is identical to one or both of:
a material of a matrix of the semiconductor substrate (Peng paragraph [0052], can be same or different material that substrate), and
a material of the channel.
Regarding claim 6, Cheng teaches a method for manufacturing a GAA transistor, comprising:
providing a semiconductor substrate (Fig. 33, substrate 202);
forming a doped structure (doped structure 206) inlaid in the semiconductor substrate (Fig. 31 and 33), wherein primary carriers of the doped epitaxial structure are opposite in polarity to primary carriers of the source and the drain (paragraph [0015]);
forming an active structure (active structure 500) on the semiconductor substrate, wherein the active structure comprises a source (240), a drain (240), and a channel (2080) between the source and the drain, and the doped structure is disposed beneath the channel and not beneath the source and the drain (Fig. 33); and
forming a gate stack structure (256) surrounding the channel, wherein a portion of the gate stack structure beneath the channel is disposed between the doped structure and the channel (Fig. 31 and 33).
Cheng does not teach the doped structure is epitaxial. However, Peng teaches that instead of the implantation method of Cheng, a doped epitaxial anti punch-through can be formed (Peng Fig. 5A-D, epitaxial APT 512). It would have been obvious to a person of skill in the art at the time of the effective filing date that the implanted APT layer of Cheng could have been replaced by a doped epitaxial APT layer because Peng teaches that this allows for more customization in the material of the APT layer, such as thickness and material (Peng paragraph [0052]).
Allowable Subject Matter
Claims 1-8 and 12 are 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:
Regarding claims 7-8 and 12, the prior art, alone or in combination, fails to teach or suggest forming a doped epitaxial material which fills the groove fully.
Conclusion
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/EVAN G CLINTON/Primary Examiner, Art Unit 2899
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