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.
Claims 1-2, 4, 6-9, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over K. Ramkumar et al (U. S. Patent Application: 2015/0187960, here after Ramkumar), further in view of Anton Mauder et al (U. S. Patent Application: 2018/0175150, here after Mauder), and Miyatani Kotaro et al (Japanese Patent: 7134263, here after Kotaro).
Claims 1-2 are rejected. Ramkumar teaches a method for forming an oxide film, by using an apparatus (vapor deposition, CVD) [0123, 0159] the method comprising steps of:
(a) depositing a first film composed of a nitride film (silicon nitride) (604, charge trapping layer) on a substrate (600) [0058, 0065, 0065];
(b) exposing the film to oxidize the first thin film (OH radicals to induce a bond between oxygen(O) of the OH radicals and SiN (oxidize the first thin film)), thereby forming an oxynitride film comprising SiON in the first thin film [0068]; and
(c) forming an insulating film (606) comprising silicon dioxide on the first thin film [0067, 0068]. Since oxidation is done by radical oxidation, therefore nitrogen from top layer removes and oxygen diffuses inside therefore concentration of an SiON component (nitrogen concentration) in a lower part of the oxynitride film is lower than that in an upper part of the oxynitride film. Ramkumar does not teach repeating deposition of silicon nitride film and radical oxidation process. Mauder teaches a method of making silicon oxynitride by radical oxidation and teaches deposition of silicon nitride and radical oxidation to form silicon oxide film and teaches repeating this process [0028] to achieve desirable film thickness [0094, 0096]. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention was made to have a method of Ramkumar where process of depositing the nitride film and radical oxidation repeated (which number of deposition controls exposure time and amount of radicals), because it helps achieving desirable thickness. Ramkumar does not teach spraying OH radicals. Kotaro teaches generating OH radicals for oxidizing source in vapor deposition apparatus by showerhead [page 4 paragraph 5]. Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention was made to have a method of Ramkumar and Mauder, where the OH radicals are generated by Kotaro method, because it is suitable way to produce OH radicals.
Claim 4 is rejected for the same reason claim 1 is rejected above, and it is
obvious that SiN reacts with the OH radicals to form SiON in step (b) if the first thin film
is composed of SiN.
Claim 6 is rejected. Ramkumar teaches exposing to OH radicals in step (b) is
performed at a process temperature of 600-900C [0068, 0054]. Although Ramkumar
does not teach 480 to 730 °C. However, overlapping ranges are prima facie evidence of
obviousness. It would have been obvious to one having ordinary skill in the art to have
selected the portion of [overlapping range] that corresponds to the claimed range. In re
Malagari, 182 USPQ 549 (CCPA 1974). layer comprising silicon oxy nitride or silicon
nitride by ALD (depositing thin films) [0037]. Therefore, it would have been obvious to
one of ordinary skill in the art at the time of the invention was made to have a method of
Ramkumar when the radical oxidation is at 600-730C, because one having ordinary skill
in the art to have selected the portion of overlapping range that corresponds to the
claimed range in absence of criticality.
Claim 7 is rejected. Ramkumar [0004] and Mauder [0003] both teach process of forming a gate oxide film during a process of forming a semiconductor device.
Claim 8 is rejected, since oxidation is done by radical oxidation, therefore oxygen
diffuses inside and convert the silicon oxynitride to silicon oxide, therefore concentration
of an SiO component in an upper part of the oxynitride film is higher than in a lower part
of the oxynitride film is lower than that SiO component in a lower part of the nitride film.
Claim 9 is rejected, an oxidation is done by radical oxidation therefore in step (b),
a concentration of SiO or SiON in the first thin film is adjusted by controlling a concentration (amount and energy) of the OH radicals.
Claim 11 is rejected as Ramkumar teaches exposing the OH radicals in step (b)
is performed without using a plasma method (radical processing method) [0048].
Response to Arguments
Applicant’s arguments, see Remarks, filed 06/18/26, with respect to the rejection(s) of claim 1 under 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Mauder et al. Mauder in fact teaches process of repeating deposition of silicon nitride layer and radical oxidation to obtain silicon oxide film, which in fact can control the thickness of silicon oxide film (and concentration of nitrogen) by number of cycles and total exposure to oxidant radicals.
The applicant argues none of the cited references teach a concentration gradient of SiON components in nitride film. However, it is obvious that since oxidation is done by radical oxidation, therefore nitrogen from top layer removes and oxygen diffuses inside therefore concentration of an SiON component (nitrogen concentration) in a lower part of the oxynitride film is lower than that in an upper part of the oxynitride film.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TABASSOM TADAYYON ESLAMI whose telephone number is (571)270-1885. The examiner can normally be reached M-F 9:30-6.
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/TABASSOM TADAYYON ESLAMI/Primary Examiner, Art Unit 1718
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