DETAILED ACTION
Claims 1-5 are pending before the Office for review.
In the response field April 23, 2026:
Claim 1 was amended.
No new matter is present.
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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on April 23, 2026 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-5 are rejected under 35 U.S.C. 103 as being unpatentable over NAJAFI et al (U.S. Patent 6,884,732) in view of JOSEPH et al (U.S Patent Application Publication 2020/0135898), VORA et al (U.S. Patent Application Publication 2020/0271850) and NGUYEN et al (U.S. Patent 5,821,169).
With regards to claims 1 and 4, Najafi discloses a method of deep etching a substrate, the method comprising: disposing a hard mask layer (24) on the substrate (22) (Figure 4a); performing a deep etch of the structure using a single etch recipe that etches both the hard mask and the substrate wherein the deep etch provides a multilevel pattern into the substrate (Figure 2a) (Col. 4 lines 5-25).
Najafi does not explicitly disclose etching a first multi-level pattern into the hard mask layer using two or more iterations of photoresist patterning followed by etching to provide etched features in the hard mask layer having two or more depths, wherein the single etch recipe has an etch rate in the substrate at least 10x its etch rate and at least 100X in the hard mask layer; wherein the deep etch is performed for a time sufficient to at least partially etch through the hard mask layer, thereby deep-etching a second multi-level pattern into the substrate that corresponds to the first multi- level pattern, but has magnified vertical feature dimensions wherein feature depths of the second multi-level pattern depend on corresponding feature depths of the first multi- level pattern.
Vora discloses a method of etching a variable etch depths in a substrate 710 using a masking layer comprising a hard mask and photoresist layer (734, 720) wherein the combination of photoresist and hardmask provide a pattern of varying heights and wherein the substrate is etched in a single etch step to form a variety of trenches of variable depths (Figure 7E) (Paragraphs [0095]-[0097]) Nguyen discloses a method of etching a substrate comprising an interlevel dielectric (10), hardmask layer (12) and photoresist (14) wherein the pattern photoresist is transferred into the hardmask layer which is transferred into the underlying substrate and layers wherein the depth of the features in the underlying substrate corresponds to the depth of the photoresist pattern which was subsequently transferred to the hardmask layer (Figures 2-8 Col. 8 line13-67). Joseph discloses a method of etching a high aspect ratio etching in a silicon substrate using a hardmask wherein the one or more hardmask can exhibit a selectivity of 10 during the dry etch process and wherein the etching is done with the hardmask to etch the pattern into the substrate (Paragraphs[0025], [0027]-[0033]). Therefore Najafi as modified by Vora and Joseph renders obvious etching a first multi-level pattern into the hard mask layer using two or more iterations of photoresist patterning followed by etching to provide etched features in the hard mask layer having two or more depths, wherein the single etch recipe has an etch rate in the substrate at least 10x its etch rate in the hard mask layer; wherein the deep etch is performed for a time sufficient to at least partially etch through the hard mask layer, thereby deep-etching a second multi-level pattern into the substrate that corresponds to the first multi- level pattern, but has magnified vertical feature dimensions wherein feature depths of the second multi-level pattern depend on corresponding feature depths of the first multi- level pattern. 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, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I) In addition it would have been prima facie obvious to optimize the etch rate of the substrate to amounts including Applicant’s claimed amount of at least 100x its etch rate in the hardmask in order to etch the desired depth while the hardmask is thinning as taught by the modified teachings of Najafi (Joseph Paragraph [0033], MPEP 2144.05(II)(A))
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the method of Najafi to include the multilevel pattern as rendered obvious by Vora because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the multilevel pattern as rendered obvious by Vora. MPEP 2143
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the method of Najafi to include the etch rate as rendered obvious by Joseph because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the etch rate as rendered obvious by Joseph. MPEP 2143
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the method of Najafi to include multilevel pattern etching depths as rendered obvious by Nguyen because the reference of Nguyen teaches that the multilevel hardmask allows for the replication of the photoresist profile without unintended etching and micro loading (Col. 4,nes 21-45) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the multilevel pattern etching depths as rendered obvious by Joseph. MPEP 2143
With regards to claim 2, the modified teachings of Najafi renders obvious wherein the hard mask layer comprises silicon dioxide (Joseph Paragraph [0029]) and wherein the substrate comprises silicon (Najafi Col. 4 lines 8-25, Joseph Paragraph [0027]).
With regards to claim 3, the modified teachings of Najafi renders obvious wherein the thickness of the hard mask layer is 5nm 0 250nm (Joseph paragraph [0029]) which render obvious Applicant’s claimed amount of wherein a thickness of the hard mask layer is 3 microns or less. 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, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
With regards to claim 5, the modified teachings of Najafi renders obvious wherein the second multi-level pattern includes features having an aspect ratio of greater than 2 (Najafi Col. 2 lines 18-22 Joseph Paragraph [0025] discloses a high aspect ratio) which render obvious Applicant’s claimed height/width aspect ratio of 10 or more. 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, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
Response to Arguments
Applicant’s arguments, see pages 4-7 of Applicant’s response, filed April 23, 2026, with respect to the rejection(s) of claim(s) 1-5 under 103 have been fully considered and are persuasive. Applicant’s amendments has overcome the rejection of record. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of NGUYEN et al (U.S. Patent 5,821,169).
Conclusion
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713
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