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 with traverse of Invention I in the reply filed on 3/4/2026 is acknowledged. The traversal is on the ground(s) that there is no serious burden on the examiner. This is not found persuasive because the inventions require a different field of search (e.g., searching different classes /subclasses or electronic resources, or employing different search strategies or search queries)
The requirement is still deemed proper and is therefore made FINAL.
Claims 14-20 withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected Invention, there being no allowable generic or linking claim.
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(s) 1, 3-5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Ryu et al (KR 20060007693; hereinafter Ryu) in view of Tsai et al (US 2018/0175170; hereinafter Tsai).
Regarding claim 1, Figs 4a-4c of Ryu discloses a method of forming an electrical contact in semiconductor structure comprising:
performing a selective deposition process (Fig 4a) on a semiconductor structure having a semiconductor region (10; Fig 4a) and a dielectric layer (12; Fig 4a) having a trench (14; Fig 4a) therewithin, the selective deposition process comprising epitaxially forming (Abstract; Fig 4a) a contact layer (16; Fig 4a) on the semiconductor region within the trench (14; Fig 4a) of the dielectric layer.
Ryu discloses forming a dopant (N+ region) in the epitaxially formed contact layer and heat treating (Page 3).
However Ryu does not expressly disclose performing a microwave anneal process to activate the dopants in the epitaxially formed contact layer.
In the same field of endeavor, Tsai discloses a microwave annealing to activate or diffuse the dopants into a contact layer (¶ [0013]).
Accordingly it would have been obvious to the person in the ordinary skill in the art before the effective filing date of the invention such that a microwave annealing process is used to activate the dopant into a contact layer as it is well known and suitable technique known in the art and it also offer rapid heating rates and sharp temperature gradients (¶ [0013]).
Regarding claim 3, Figs 4a-4c of Ryu discloses the semiconductor region (10; Fig 4a) comprises silicon doped with n-type dopants (Page 3); and
the contact layer (16; Fig 4a) comprises silicon doped with n-type dopants (Page 3).
Regarding claim 4, Figs 4a-4c of Ryu discloses the contact layer (16; Fig 4a) comprises silicon doped with n type dopant (Page 3).
However Ryu does not expressly disclose the contact layer comprises silicon doped with phosphorus (P) with a concentration of between 1019 cm-3 and 5 x 1021 cm-3.
In the same field of endeavor, Tsai discloses a n-type dopant is phosphorus and concentration of a n-type dopant can be 1021 cm-3 which anticipates the claimed range (¶ [0023]).
Accordingly it would have been obvious to the person in the ordinary skill in the art before the effective filing date of the invention such that the n-type dopant is a phosphorus with a concentration of between the claimed range as it is well known and suitable n-type dopant known in the art.
Regarding claim 5, Ryu discloses the selective deposition process is performed at a temperature of between 200 °C and 800 °C (Page 3).
Regarding claim 8, Ryu discloses subsequent to the microwave anneal process,
Performing a blanket deposition process to form a metal layer on the contact layer (Fig 4b) and
Performing a metal fill process to form a contact plug in the trench (Fig 4c).
Claim(s) 2 is rejected under 35 U.S.C. 103 as being unpatentable over Ryu et al (KR 20060007693; hereinafter Ryu) in view of Tsai et al (US 2018/0175170; hereinafter Tsai) as applied to claim 1 and further in view of Xu et al (US 2018/0145034; hereinafter Xu).
Regarding claim 2, Ryu does not expressly disclose the selective deposition and the microwave anneal process are performed without breaking vacuum environment.
In the same field of endeavor, Xu discloses all the processes including selective deposition and the anneal process is done in chambers in a controlled vacuum environment. ([0020], ¶ [0041])
Accordingly it would have been obvious to the person in the ordinary skill in the art before the effective filing date of the invention such that the selective deposition process and the microwave anneal process are performed without breaking vacuum environment as taught by Xu in order to perform the processes without an air break in the process (¶ [0041]).
Allowable Subject Matter
Claim 6 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.
Regarding claim 6, the prior art of record, either singularly or in combination, does not disclose or suggest the combination of limitations including “performing a cavity shaping process to form a cavity on the exposed surface of the semiconductor region within the trench”.
Claims 8-13 are allowed.
Regarding claim 8, the prior art of record, either singularly or in combination, does not disclose or suggest the combination of limitations including “performing a cavity shaping process to form a cavity on the exposed surface of the semiconductor region within the trench”.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Chen (US 2022/0208829)
Clark et al (US 2019/0295903)
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/RATISHA MEHTA/ Primary Examiner, Art Unit 2817
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