DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Specification
The specification has not been checked to the extent necessary to determine the presence of all possible minor errors. Applicant’s cooperation is requested in correcting any errors of which applicant may become aware in the specification.
Claim Analysis
The Examiner notes that present claims 1 – 20 are a set of product claims that contain structural limitations that are defined by the recited process of forming such structural limitations, i.e. product-by-process claim limitations. Thus, the presented claims are product-by-process claims.
"[E]ven though product-by-process claims are limited by and defined by the process, determination of patentability is based on the product itself. The patentability of a product does not depend on its method of production. If the product in the product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product was made by a different process." In re Thorpe, 777 F.2d 695, 698, 227 USPQ 964, 966 (Fed. Cir. 1985)
The structure implied by the process steps should be considered when assessing the patentability of product-by-process claims over the prior art, especially where the product can only be defined by the process steps by which the product is made, or where the manufacturing process steps would be expected to impart distinctive structural characteristics to the final product. See, e.g., In re Garnero, 412 F.2d 276, 279, 162 USPQ 221, 223 (CCPA 1979).
Claim Rejections - 35 USC § 103
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.
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.
Claim(s) 1, 9 – 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Terui et al. US 2024/0234132 A1 (hereinafter “Terui”) in view of Williams & Wasilik “Etch Rates for Micromachining Processing Processing ––– Part II”. Journal of Microelectromechanical Systems, Vol. 12, No. 6, December 2003 (hereinafter Wasilik).
Regarding claims 1, 9, 10, 11, 12, 13 – 20:
Terui is directed to substrate processing methods and substrates processed from such methods (Abstract). Terui discloses modified SiOC films formed on wafers comprising: a wafer [substrate]; and a silicon oxycarbide layer overlying the substrate ([0174] – [0177]; Fig. 8). In one embodiment, Terui discloses a sample 2 where the SiOC film has a dielectric constant of 4.2 [less than 4.5, 4.25, and between 3.5 and 4.25 ] and a wet etch rate of 16 Å /min [1.6 nm/min] when etched by aqueous hydrogen fluoride diluted to 1% [1% dilute hydrofluoric acid] ([0177]).
Terui does not expressly teach that the SiOC film has a wet etch rate of less than 1 nm/minute in 0.5% dilute hydrofluoric acid.
However, as discussed above, Terui discloses the etch rate at a more aggressive concentration of etchant at 1%.
Williams is directed to the general knowledge of one of ordinary skill in the art pertaining to the etch rates of known materials. Williams discloses with respect to the closely related species of SiO films, hydrogen fluoride etches silicon dioxide at room temperatures (page 771). The etch rate of SiO films is linear with concentration for dilutions in the 10:1 [10% dilute] to 1:100 [1% dilute] range. As shown in Table VIII (page 771), the SiO2 thermal oxide etch rate at HF concentrations of 10:1 (10%), 25:1 (4%) and 100:1 (1%) are respectively in nm/min: 23, 9.7 and 2.3. The Examiner notes that when extrapolated to a concentration of 0.5%, the thermal oxide etch rate can be expected to be at 1.37 nm/min, or 60% of the value of reported thermal oxide etch rate with 1% HF solution.
Therefore, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have reasonably expected that sample 2 having a reported wet etch rate of 1.6 nm/min when subjected to a 1% dilute HF solution would have a wet etch rate of less than 1 nm/min, 0.8 nm/min and/or within the ranges of 0.4nm/minute and 0.9 nm/minute because Williams suggest that etch rates are linearly proportional to the concentration of the hydrogen fluoride in a testing solution; thus the etch rate of the same sample at the lower 0.5% etch rate can be expected to be less than or otherwise close to the claimed wet etch rate where the behavior of SiOC would be similar to that of SiO.
Terui also does not expressly teach that the silicon oxycarbide layer is formed by the recited process steps (… providing the substrate … electrode without pulsing plasma power, … ”
However, as noted above, the patentability of a product does not depend on its method of production. Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983). Accordingly, the particular steps of the process used for producing the SiOC layer (including those described in present claims 13, 14, 15, 16, 17, 18, 19, 20) are not given patentable weight.
Claim(s) 1 – 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al. US 2021/0388499 A1 (hereinafter “Zhang”).
Regarding claims 1 – 20:
Zhang is directed to low-k [low dielectric constant] films (Abstract). In embodiments, Zhang discloses a structure comprising: a substrate 202 with a gate stack 206 [semiconductive patterned feature, protruding feature, meeting claims 2, 3, 4, 5] and a silicon oxycarbide or silicon oxycarbonitride spacer material 208 surrounding the gate stack 206 [meeting claims 6, 7, 8] (Fig 2; [0064]; Claim 18). The silicon oxycarbonitride film is produced by an atomic layer deposition technique (Fig. 1; [0012], [0023]).
Zhang does not expressly teach an embodiment of their structure wherein the dielectric constant of the dielectric constant is less than 4.5 and wherein a wet etch rate of the silicon oxycarbide layer in 0.5% dilute hydrofluoric acid is less than 1 nm/minute.
However, Zhang discloses that embodiments of their low-k film may have dielectric constants of specifically about 2.25, about 2.5, about 2.75, ect and embodiments of their low-k film having a wet etch rate of e.g about 0.5 Å/min [.005 nm/min], 0.75 Å/min [.075 nm/min], 1.0 Å/min [0.1 nm/min] , ect when exposed to a 1:100 hydrofluoric acid solution (1% dilute) ([0018]). Furthermore, Zhang suggests that the amount of retained carbon in the silicon oxycarbide film lowers observed wet etching rates by hydrogen fluoride after the silicon oxycarbide film undergoes an ashing process as part of semiconductor manufacturing ([0018]). Zhang further discloses that there is a general desire in the art to have silicon oxycarbide and silicon oxycarbonitride films that are both low-k and low etch rate ([0004]). Finally, Zhang discloses that the amount of carbon in the resultant silicon oxycarbide film can be controlled ([0021], [0052]).
Zhang therefore discloses low-k film embodiments having overlapping ranges and values of dielectric constant. Zhang also discloses low-k film embodiments with wet etch rates that are overlapping with stronger etching solutions, and thus Zhang reasonably implies low-k film embodiments with even smaller etch rates when compared to weaker 0.5 dilute hydrofluoric acid solutions.
In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art”, a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66(Fed. Cir. 1997). See MPEP 2144.05.
Additionally, it would have been obvious to one of ordinary skill before the effective filing date of the claimed invention to have modified the reaction conditions of the process of Zhang to arrive to a low-k silicon oxycarbide film having the recited dielectric constants and wet etch rates combined as a matter of routine experimentation in order to produce spacer films with minimized dielectric constants and to survive front-end-of-line semiconductor manufacturing, as taught by Zhang. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Zhang also does not expressly teach that the silicon oxycarbide layer is formed by the recited process steps (… providing the substrate … electrode without pulsing plasma power, … ”
However, as noted above, the patentability of a product does not depend on its method of production. Once the examiner provides a rationale tending to show that the claimed product appears to be the same or similar to that of the prior art, although produced by a different process, the burden shifts to applicant to come forward with evidence establishing an nonobvious difference between the claimed product and the prior art product. In re Marosi, 710 F.2d 799, 803, 218 USPQ 289, 292-33 (Fed. Cir. 1983). Accordingly, the particular steps of the process used for producing the SiOC layer (including those described in present claims 13, 14, 15, 16, 17, 18, 19, 20) are not given patentable weight.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOSE I HERNANDEZ-KENNEY whose telephone number is (571)270-5979. The examiner can normally be reached M-F 6:30-3:30.
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/JOSE I HERNANDEZ-KENNEY/
Primary Examiner
Art Unit 1717
Prosecution Insights