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
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-3, 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ji (US 2014/0094035 A1) in view of Oomori (US 2017/0084467 A1).
Claim 1-2:
Ji teaches a method for using amorphous carbon to provide gap fill for gap features during semiconductor processing [0003]. The process steps are illustrated in Fig. 1 and include a deposition step of depositing an amorphous carbon layer in a gap 103, followed by conducting etching to remove deposited carbon at gap entry 105, and repeating the deposition and etching 107 until the gap is filled 111. The entire process takes place in a PECVD apparatus where the deposition step is PECVD [0039] and the etching step is plasma etching [0046]. Both processes use a combination of high and low radio frequency to generate the plasma (Table 1).
Ji does not teach the inclusion of carbon dioxide in the etching gas.
However, Oomori teaches a method for etching amorphous carbon (abstract) where it is known to add additional conventional gases to the etching gas in order to adjust the etching rate and selectivity and includes carbon dioxide [0037].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Ji and add carbon dioxide to the etching gas in order to adjust the etching rate and selectivity.
Claim 3:
Etching a carbon layer will necessarily result in the production of a carbon compound.
Claim 5:
Ji teaches the substrate temp, RF power, and pressure (Table 1). The flow rate of carbon dioxide is not explicitly taught. However, it is a result effective variable (see above) and its value would have been obvious through routine optimization.
Claim(s) 1-7, 9-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ji (US 2014/0094035 A1) in view of Lee (US 2025/0243585 A1; PCT/US2023/015209, PCT Filing Date 3/14/23).
Claims 1-2, 6, 9-10, 13:
Ji teaches a method for using amorphous carbon to provide gap fill for gap features during semiconductor processing [0003]. The process steps are illustrated in Fig. 1 and include a deposition step of depositing an amorphous carbon layer in a gap 103, followed by conducting etching to remove deposited carbon at gap entry 105, and repeating the deposition and etching 107 until the gap is filled 111. The entire process takes place in a PECVD apparatus where the deposition step is PECVD [0039] and the etching step is plasma etching [0046]. Both processes use a combination of high and low radio frequency to generate the plasma (Table 1).
Ji does not teach the inclusion of carbon dioxide in the etching gas or deposition of a layer during the etching step.
However, Lee teaches the process of simultaneously etching and depositing a deposition layer (abstract). The material being etched includes amorphous carbon and the etch gas includes an oxygen component such as carbon dioxide combined with methane [0020].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to practice the method of Ji and modify the etching step to further include depositing a deposition layer. Lee states it is suitable to combine etching and deposition for the purpose of providing control over etch rates, bowing, roughness, and selectivity [0023].
Claims 3-4, 12:
Etching a carbon layer will necessarily result in the production of a carbon compound. Lee teaches the deposited layer is a carbide [0038].
Claim 7, 14:
Lee teaches a post etch step [0022;0031].
Claim 11:
Ji teaches the substrate temp, RF power, and pressure (Table 1). The flow rate of carbon dioxide is not explicitly taught. However, it is a result effective variable for providing oxygen radical for etching carbon (Lee [0040]) and its value would have been obvious through routine optimization.
Claim(s) 8, 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Ji (US 2014/0094035 A1) in view of Lee (US 2025/0243585 A1; PCT/US2023/015209, PCT Filing Date 3/14/23) in view of Davis (US 2004/0200574 A1).
Previously cited prior art does not teach a CMP process. However, Davis teaches post-etch processes include CMP [0028]. Therefore, 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 CMP process after etching as a post-etch step.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALEX A ROLLAND whose telephone number is (571)270-5355. The examiner can normally be reached M-F 10-6:30.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Curtis Mayes can be reached at 5712721234. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALEX A ROLLAND/Primary Examiner, Art Unit 1759
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