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
Claims 1-8 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 11/23/2025.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
Claim Objections
Claims 9 and 11 are objected to because of the following informalities:
Claim 9 includes an apparent typographic error, and should be amended to recite:
“…forming an air gap in the first dielectric layer and the second dielectric layer, wherein a size of the air gap at a side away from the orifice is larger than a size of the air gap at a side close to the orifice.
Claim 11 includes apparent grammatical errors, and should be amended to recite:
11. (Currently Amended) The method for fabricating the semiconductor structure according to claim 9, wherein removing the partial thickness of the first dielectric layer not under the barrier layer comprises:
using a first etchant to remove the partial thickness of the first dielectric layer not under the barrier layer through a chemical etching process, wherein the first etchant has a selective etch ratio effect on the barrier layer and the first dielectric layer of 1:10;
wherein removing the barrier layer comprises:
using a second etchant to remove the barrier layer through a chemical etching process, wherein the second etchant has a selective etch ratio effect on the barrier layer and the first dielectric layer of 12:1.
Appropriate correction is required.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 9 and 14 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kim et al (US 2012/0280300 A1)
Regarding claim 9, Kim teaches a method for fabricating a semiconductor structure (¶ 0022 & fig. 2J among others), comprising:
providing a conductive layer (¶ 0027 & fig. 2A: MP/109) comprising a channel (cavity in MP/109 extending to surface of 101);
forming a first dielectric layer (¶ 0030: 115), wherein the first dielectric layer is disposed on the inner wall of the channel (fig. 2A: 115 formed on inner wall of MP cavity), wherein a thickness of the first dielectric layer at a side close to an orifice of the channel is greater than a thickness of the first dielectric layer at a side away from the orifice of the channel (fig. 2A: lateral thickness of 115 proximal to top of MP/109 cavity greater than thickness of 115 distal from top of MP/109 cavity);
forming a barrier layer (¶ 0039: 125), wherein the barrier layer is disposed on the first dielectric layer at a side close to the orifice of the channel (fig. 2E: 125 disposed on 115 proximal to top of 109);
removing a portion of the thickness of the first dielectric layer not under the barrier layer (¶ 0041 & fig. 2F: 125 and 115 removed sequentially, such that a portion of 115 exposed from 125 is removed);
removing the barrier layer (¶ 0045 & fig. 2G: 125 removed);
forming a second dielectric layer (¶ 0050: 137), wherein the second dielectric layer is disposed on the first dielectric layer at a side close to the orifice (fig. 2J: 137 disposed on 115 proximal to top of MP/109 cavity), and wherein the second dielectric layer blocks the orifice of the channel (fig. 2J: 137 blocks cavity proximal to top of MP/109); and
forming an air gap (¶ 0050: 135) in the first dielectric layer and the second dielectric layer (fig. 2J: 135 formed in 115 and 137), wherein a size of the air gap at a side away from the orifice is larger than a size of the air gap at a side close to the orifice (fig. 2J: size of 135 distal from top of MP/109 cavity larger than size of 135 proximal to top of MP/109 cavity).
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Regarding claim 14, Kim teaches the method for fabricating the semiconductor structure according to claim 9, wherein the first dielectric layer comprises a first part close to the orifice and a third part at a bottom of the orifice (figs. 2B and/or 2D: 115 includes portions proximal to and distal from opening of cavity);
wherein forming the barrier layer comprises:
disposing the barrier layer on the first part and the third part of the first dielectric layer (fig. 2E: 125 formed on top and bottom portions of 115);
wherein removing a partial thickness of the first dielectric layer not under the barrier layer comprises:
removing the partial thickness of the first dielectric layer from the first dielectric layer except for the first part and the third part (figs. 2C and/or 2D: portion of 115 above opening of cavity removed), and
forming a second part of the first dielectric layer (¶ 0037 & fig. 2C: 121 formed as byproduct of 115); and
wherein, a thicknesses of the first part and a thicknesses of the third part are both greater than a thickness of the second part (fig. 2D: lateral thickness of upper/lower portions of 115 greater than thickness of 121).
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.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Kim as applied to claim 9 above, and further in view of Lu et al. (PG Pub. No. US 2021/0043569 A1).
Regarding claim 10, Kim teaches the method for fabricating the semiconductor structure according to claim 9, wherein forming the barrier layer comprises:
forming the barrier layer by a deposition process (¶ 0039: 125 deposited);
wherein, a thickness of the barrier layer at a side close to the orifice is greater than a thickness of the barrier layer at a side away from the orifice (fig. 2E: thickness of 125 proximal to top of MP/109 cavity greater than thickness of 125 distal from MP/109 cavity), and wherein the thickness of the barrier layer gradually decreases along the direction pointing away from the orifice (fig. 2E: lateral thickness of 125 gradually decreases in vertical direction toward element 107).
Kim further teaches the barrier layer comprises dielectric material (¶ 0039).
Kim is silent to the barrier layer deposition comprising physical vapor deposition.
Lu teaches a method of forming a barrier layer (¶ 0042: 1802, similar to 125 of Kim) by physical vapor deposition (¶ 0042: 1802 formed by physical vapor deposition).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to configure the barrier layer deposition of Kim with physical vapor deposition, as a means to control gapfill properties (Lu, ¶ 0042 & fig. 18), thereby optimizing the thickness of the barrier layer in the channel.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Kim as applied to claim 9 above, and further in view of Kim (Patent No. US 5,441,909 A, hereinafter referenced as ‘Kim-909’).
Regarding claim 11, Kim teaches the method for fabricating the semiconductor structure according to claim 9, wherein removing the partial thickness of the first dielectric layer not under the barrier layer comprises:
using a first etchant to remove the partial thickness of the first dielectric layer not under the barrier layer through a chemical etching process (¶¶ 0041-0042: portion of 115 removed by etch process including at least one chemical), wherein the first etchant has a selective etch ratio effect on the barrier layer and the first dielectric layer (¶ 0039: 125 has etch selectivity with respect to 115);
wherein removing the barrier layer comprises:
using a second etchant to remove the barrier layer through a chemical etching process (¶ 0045: 125 removed by etch process), wherein the second etchant has a selective etch ratio effect on the barrier layer and the first dielectric layer (¶ 0039, fig. 2G: 125 removed selective to 115).
Kim does not teach wherein the first etchant has a selective etch ratio of 1:10, or the second etchant has a selective etch ratio effect on the barrier layer and the first dielectric layer of 12:1.
Kim-909 teaches an etchant having a selective etch ratio effect on first and second dielectric layers (col. 2 lines 5-22: 6 and 8, including materials similar to 115, 125 and 137 of Kim) of 10:1 (col. 3 lines 12-13: etch selectivity of at least 10:1).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to adjust the etch ratios of the etchants of Kim, as a means to ensure appropriate volumes for the air gaps subsequently formed.
Furthermore, it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. In the instant case, the general conditions of selective etch ratios of at least 10:1 are taught by Kim-909, such that arriving at the claimed etch selectivities of 10:1 and 12:1 would be a matter of routine skill.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Kim as applied to claim 14 above, and further in view of Hsiao et al. (PG Pub. No. US 2015/0262929 A1).
Regarding claim 15, Kim teaches the method for fabricating the semiconductor structure according to claim 14, wherein forming the first dielectric layer comprises:
forming the first dielectric layer by a deposition process (¶ 0032: 115 deposited);
wherein, the thickness of the first part at the side close to the orifice is greater than the thickness of the first part at the side away from the orifice (fig. 2D: thickness of 115 proximal to opening of cavity greater than thickness of 115 distal from opening of cavity), and wherein the thickness of the first part gradually decreases along the direction pointing away from the orifice (fig. 2D: thickness of 115 gradually decreases away from opening of cavity).
Kim does not teach the first dielectric layer by a chemical vapor deposition process.
Hsiao teaches a method including forming a first dielectric layer (¶ 0047: 802, similar to 115 of Kim) by a chemical vapor deposition process (¶ 0048: 802 deposited by CVD).
It would have been obvious to one of ordinary skill in the art at the time the invention was filed to form the first dielectric layer of Kim with a chemical vapor deposition process, as a means to provide an air gap (Hsiao, ¶ 0048: 210, similar to 113 of Kim).
Since all the claimed elements were known in the prior art, and one skilled in the art could have combined the elements as claimed by known methods with no change in their respective functions, the combination would have yielded nothing more than predictable results to one of ordinary skill in the art. KSR Int'l Co. v. Teleflex Inc., 550 U.S. 538, 416, 82 USPQ2d 1385, 1395 (2007); Sakraida v. AG Pro, Inc., 425 U.S. 273, 282, 189 USPQ 449, 453 (1976); Anderson' s-Black Rock, Inc. v. Pavement Salvage Co., 396 U.S. 57, 62-63, 163 USPQ 673, 675 (1969); Great Atlantic & P. Tea Co. v. Supermarket Equip. Corp., 340 U.S. 147, 152, 87 USPQ 303, 306 (1950). See MPEP § 2143.02. In the instant case, the deposition of Kim could be performed with the chemical vapor deposition of Hsiao, with no change in their respective functions.
Allowable Subject Matter
Claims 12-13 are 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.
The following is a statement of reasons for the indication of allowable subject matter: The prior art fails to teach or clearly suggest the limitations stating:
“wherein the first etchant is a hydrofluoric acid solution;
wherein in the hydrofluoric acid solution, a ratio of hydrofluoric acid to water is in the range of 200:1 -300:1, and wherein an etch process time of the first etchant is 100 seconds-140 seconds;
and/or wherein the second etchant is a mixture of ammonia, hydrogen peroxide and water, wherein a ratio of ammonia, hydrogen peroxide and water is 1:4:130, and wherein an etch process time of the second etchant is in a range of 40 seconds-80 seconds” as recited in claim 12, and
“the method further comprises:
forming a third dielectric layer, wherein the third dielectric layer is located outside the channel and covers the conductive layer close to the orifice; wherein, at least part of the first dielectric layer is located outside the channel, and the first dielectric layer located outside the channel covers the third dielectric layer;
wherein forming the barrier layer comprises:
disposing part of the barrier layer outside the channel, wherein the barrier layer disposed outside the channel covers the first dielectric layer;
wherein, at least part of the second dielectric layer is located outside the channel, wherein the second dielectric layer located outside the channel covers the first dielectric layer’ as recited in claim 13.
Conclusion
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/BRIAN TURNER/Examiner, Art Unit 2818