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
Applicant’s election without traverse of claims 9-20 & 21-20 in the reply filed on 10/14/2025 is acknowledged.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 9-10, 12-16 & 18-28 are rejected under 35 U.S.C. 103 as being unpatentable over HONG (US Pub. 2014/0145302) in view of TIAN et al. (US Pub. 2012/0211865).
Regarding claim 9, HONG teaches a method, comprising:
forming a recess 304 in a dielectric layer 302 to expose a surface of a copper metallization layer 303 (Fig. 3 & Para [0021]);
forming, using physical vapor deposition (PVD) (Para [0028]), a first barrier layer 305 on sidewalls of the recess 304 and the exposed surface of the copper metallization layer 303 (layer 305 comprises TiN or TaN that are known barrier material and as such read as first barrier layer, see Fig. 4);
forming a carbon-based layer 306 in the recess 304, wherein a top surface of the carbon-based layer 306 is below a top surface of the dielectric layer 302 (Fig. 5-Fig.6 and Para [0031]);
etching the first barrier layer 305 to remove a portion of the first barrier layer 305 above the top surface of the carbon-based layer 306 (Fig. 7);
removing the carbon-based layer 306 to re-open the recess (Fig. 7-8); and
forming, using PVD, a second barrier layer (308 and/or 307) over the first barrier layer 305 and on sidewalls of the recess 304 (Fig. 8)
HONG is silent on forming a metal-insulator-metal (MIM) structure in the recess. However, TIAN discloses forming a metal-insulator-metal (MIM) structure (e.g. 128) in a recess (see Fig. 2). This has the advantage of employing an additional MIM capacitor within the recess to provide high capacitance density, fabrication flexibility and improved electrical performance. Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to modify the invention of HONG with the multi stack MIM capacitor structure, as taught by TIAN, so as to obtain an improved semiconductor device.
Regarding claim 10, the combination of HONG and TIAN teaches the method of claim 9, wherein a ratio of a width of the recess to a height of the recess is in a range from approximately 0.05 to approximately 0.12 (note TIAN’s Para [0047], wherein TIAN teaches a width 0.3 - 0.7 um and height of about 5 -20 um, which falls within the claim aspect ratio). These claim dimensions would have been obvious to one of the ordinary skill in the art in view of TIAN. One of the ordinary skill in the art is motivated to form device features as small as possible with large enough thickness and width to allow proper device operation, in order to save on material and processing costs. As such, it would have been obvious to use said claim ratio for the recess.
The claim is prima facie obvious without showing that the claimed ranges achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir.1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious).
Regarding claim 12, the combination of HONG and TIAN teaches the method of claim 9, wherein etching the first barrier layer 305 comprises: performing a dry etching using a chlorine-based chemical (HONG’s Para [0034 & claim 8], also note that dry etching is a form of plasma etching).
Regarding claim 13, the combination of HONG and TIAN teaches the method of claim 9, further comprising: performing a plasma treatment on the first barrier layer 305 before forming the second barrier layer (HONG’s Para [0034] & claim 8).
Regarding claim 14, HONG teaches a method, comprising:
forming a recess 304 in a dielectric layer 302 (Fig. 3);
forming a first barrier layer 305 on sidewalls and a bottom surface of the recess 304 (Fig. 4);
forming a carbon-based layer 306 in the recess 304 (Fig. 5 and Para [0031]);
etching a portion of the carbon-based layer 306, such that a top surface of a remaining portion of the carbon-based layer 306 is below a top surface of the dielectric layer 302 (Fig. 6);
etching the first barrier layer 305 to remove a portion of the first barrier layer 305 above the top surface of the remaining portion of the carbon-based layer 306 (Fig. 7);
removing the remaining portion of the carbon-based layer 306 to re-open the recess (Fig. 7-8 and respective texts); and
forming a second barrier layer (308 and/or 307) over the first barrier layer 307 and on sidewalls of the recess 304 (Fig. 8-9).
HONG is silent on forming a first metal in the recess, an insulator on the first metal, and a second metal on the insulator, wherein the first metal, the insulator, and the second metal comprise a metal- insulator-metal (MIM) structure.
However, TIAN discloses forming a first metal (e.g.130) in a recess, an insulator (e.g. 132) on the first metal, and a second metal (e.g. 134) on the insulator, wherein the first metal, the insulator, and the second metal comprise a metal- insulator-metal (MIM) structure 128 (Fig. 2). This has the advantage of employing additional MIM capacitors within the recess to provide high capacitance density, fabrication flexibility and improved electrical performance. Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to modify the invention of HONG with the multi stack MIM capacitor structure, as taught by TIAN, so as to obtain an improved semiconductor device.
Regarding claims 15-16, the combination of HONG and TIAN teaches the method of claim 14, wherein a width of the recess is in a range from approximately 0.11 micrometers (um) to approximately 0.17 um (claim 15); and wherein a height of the recess is in a range from approximately 1.5 micrometers (um) to approximately 2.0 um (claim 16) (note TIAN’s Para [0047], wherein TIAN teaches a recess/trench width 0.3 - 0.7 um and height of about 5 -20 um, which falls within the claim aspect ratio). These claim dimensions would have been obvious to one of the ordinary skill in the art in view of TIAN. One of the ordinary skill in the art is motivated to form device features as small as possible with large enough thickness and width to allow proper device operation, in order to save on material and processing costs. As such, it would have been obvious to use said claim ratio for the recess.
The claim is prima facie obvious without showing that the claimed ranges achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir.1996)(claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955)(selection of optimum ranges within prior art general conditions is obvious).
Regarding claims 18, the combination of HONG and TIAN teaches the method of claim 14, wherein forming the first metal, the insulator, and the second metal comprises: forming the first metal using physical vapor deposition (PVD);forming the insulator using PVD, wherein the insulator comprises a plurality of oxide materials; and forming the second metal using PVD (HONG teaches throughout the disclosure where first and second metal layers and insulating layers are formed by a PVD method and both HONG and TIAN teaches oxide for the insulator).
Regarding claims 19, the combination of HONG and TIAN teaches the method of claim 14, wherein the first metal and the second metal comprise titanium nitride, and the insulator comprises zirconium oxide or aluminum oxide (HONG’s Para [0026-0028,, 0039 & 0041] and TIAN’s Fig. 2 and associated text).
Regarding claim 20, the combination of HONG and TIAN teaches the method of claim 14, further comprising: performing a plasma treatment on the first barrier layer 305 before forming the second barrier layer (HONG’s Para [0034] & claim 8).
Regarding claim 21, HONG teaches a method, comprising:
forming a metal structure 309 in a dielectric layer 302 (Fig. 10);
forming a first barrier layer 305 between the metal structure 309 and the dielectric layer 302 and directly contacting a first portion of sidewalls of the dielectric layer; and
forming a second barrier layer (307 and/or 308) between the metal structure 309 and the dielectric layer 302 and directly contacting a second portion of the sidewalls of the dielectric layer 302 (Fig. 10).
HONG is silent on where the metal structure 309 is a metal-insulator-metal (MIM) structure. However, TIAN teaches a metal-insulator-metal (MIM) structure (e.g. 128) on a first barrier layer (e.g. TIN layer 112) and a second barrier layer 116 in a recess. This has the advantage of employing additional MIM capacitors within the recess to provide high capacitance density, fabrication flexibility and improved electrical performance. Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to modify the invention of HONG by replacing the metal structure 309 with the MIM capacitor structure 128 as taught by TIAN, so as to obtain an improved semiconductor device.
Regarding claim 22, the combination of HONG and TIAN teaches the method of claim 21, wherein the first barrier layer 305 has approximately 0% carbon (Fig. 8-10).
Regarding claim 23, the combination of HONG and TIAN teaches the method of claim 21, wherein the first barrier layer 112 and the second barrier layer 116 have a total thickness, at a bottom surface of the MIM structure, in a range from approximately 60 Angstroms to approximately 800 Angstrom (TIAN’s Para [0037 & 0037]). Notwithstanding, 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. Furthermore, it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art. In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980).
Regarding claim 24, the combination of HONG and TIAN teaches the method of claim 21, wherein the first barrier layer 305/112 comprises tantalum nitride, titanium nitride, molybdenum nitride, or aluminum nitride (HONG’s Fig. 10 and TIAN’s Fig. 2 and respective texts).
Regarding claim 25, the combination of HONG and TIAN teaches the method of claim 21, wherein the second barrier layer comprises tantalum, ruthenium, cobalt, or a ruthenium- cobalt alloy (HONG’s Fig. 10 and TIAN’s Fig. 2 and respective texts).
Regarding claim 26, the combination of HONG and TIAN teaches the method of claim 21, wherein the first barrier layer 305 is further between the MIM structure 128 and a copper metallization layer 303 (HONG’s Fig. 10 and TIAN’s Fig. 2).
Regarding claim 27, the combination of HONG and TIAN teaches the method of claim 21, wherein the MIM structure has a width, along a top surface of the dielectric layer 302, that is larger than a width along a bottom surface of the MIM structure (MIM structure 128 once incorporated into HONG’s device will have a larger width at the top surface than a width at the bottom surface (see HONG’s Fig. 10 and TIAN’s Fig. 2).
Regarding claim 27, the combination of HONG and TIAN teaches the method of claim 21, wherein the MIM structure has a width, at a point between a top surface of the dielectric layer and a bottom surface of the MIM structure, that is larger than a width along the bottom surface of the MIM structure (see HONG’s Fig. 10 and TIAN’s Fig. 2).
Furthermore, it would have been an obvious matter of design choice to change the shape of the recess and/or thickness of the barrier layers, since such a modification would have involved a mere change in the size/shape (e.g. thickness or width) of a component. A change in size/shape is generally recognized as being within the level of ordinary skill in the art. In re Rose, 105 USPQ 237 (CCPA 1955).
Claims 11 & 17 are rejected under 35 U.S.C. 103 as being unpatentable over HONG and TIAN as applied to claims 9 & 14 above, and further in view of Xie et al. (US Pub. 2020/0295151).
Regarding claims 11 & 17, the combination of HONG and TIAN is silent on wherein removing the carbon-based layer comprises: performing a gamma ashing using nitrogen, hydrogen, or a combination thereof. However, Xie teaches in Par a [0054], wherein removing a sacrificial layer comprises: performing a gamma ashing (dry ashing) using nitrogen, hydrogen, or a combination thereof. This has the advantage of cleanly removing the sacrificial carbon based layer from the recess. Therefore, it would have been obvious to one having ordinary skill in the art at the time the invention was effectively filed to modify the invention of HONG & TIAN with the gamma/dry ashing process, as taught by Xie, so as to completely and cleanly remove the sacrificial carbon based layer from the recess.
Conclusion
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/TIMOR KARIMY/Primary Examiner, Art Unit 2818