Attorney’s Docket Number: P202301236US01
Filing Date: 08/02/2023
Claimed Foreign Priority Date: NA
Applicant(s): Farooq et al
Examiner: Aneesa Baig
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 elections without traverse of Group II Invention, directed to a semiconductor structure, corresponding to claims 1-7, in the reply filed on 10/27/2025, is acknowledged. Applicant cancelled claim 7 and 20 also added new claim 21 and 22 from this invention.
Accordingly, pending in this application are claims 1-7,21,22 with claims 8-19 stand withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group Invention, there being no allowable generic or linking claim.
Response to Amendment
The Amendment filed on 01/29/2026, responding to the Office action mailed on 11/19/2025 has been entered. The present Office action is made with all the suggested amendments being fully considered. Applicant incorporated claim 7 language into claim 1.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
Claims 1-22 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, regards as the invention.
Claim 1 recites “a solder pad on top of and substantially aligned with the seed layer.” The language of being substantially aligned is not understood plainly to have aligned sidewalls, leading the claim to be indefinite. I.e. the center point of the layers may be aligned, with the sidewalls not aligned. For the purpose of examination, the claim will be construed as reciting -- a solder pad on top of the seed layer, the seed layer is self-aligned to the solder pad -- as best understood by the examiner in view of the original disclosure ([0010]), until further clarifications are provided by the applicant.
Claims 2-6,21,22 depend from claim 1, thus inherit the deficiencies identified supra.
Claim 22 is rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor, regards as the invention.
Claim 22 recites “wherein the sidewall of the first copper layer vertically aligns with sidewall of the seed layer” It is unclear if the limitations in bold refer to one side wall or both sidewalls as recited in claim 1, thus rendering the claim indefinite. For the purpose of examination, the claim will be construed as reciting -- wherein sidewalls of the first and the second region of the first copper layer (language from claim 1) vertically alignsidewalls of the seed layer --, as best understood by the examiner in view of the original disclosure, until further clarifications are provided by the applicant.
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 1-5, 22 are rejected under 35 U.S.C. 103 as being unpatentable over in view of Ha(US 20190214358 A1, Hereinafter HA) in view of Se-Young et al(NPL-“CrCu Based UBM (Under Bump Metallization) Study With Electroplated Pb/63Sn Solder Bumps –Interfacial Reaction and Bump Shear Strength”-PDF provided, Hereinafter Se-Young) .
Regarding claim 1, Ha (E.g., Fig 3, 5, [0001]-[0089])shows most aspects of the invention including a semiconductor structure comprising:
a seed layer, the seed layer being a copper alloy having one or more alloying elements (e.g., first lower metal film 170 may be allowed with Cr [0049]-[0052]); and
a solder pad on top of and substantially aligned with the seed layer (layers above seed layer 170),
wherein the solder pad has at least a first copper layer (e.g., first metallization layer 20),
wherein sidewalls of the first and the second region of the first copper layer are surrounded by a protective liner (e.g., Fig 5 first metal protection film 175 [0058]), the protective liner being made of nickel, gold, or a combination of nickel and gold.
While Ha shows the Cr layer under a copper or copper alloy pillar, it does not show a second region specifically that contains alloying elements from the seed layer. Se-Young, on the other hand and in a related field of bump pillars, teaches having an intermediate layer of Cr-Cu or a gradient of Cr-Cu as intermediate layers.
Se-Young (e.g., Fig 1(a)-(c) Cr/Cu four layers with gradient, Table 1, Fig 9 and 10), on the other hand and in a related field of UBM layers, teaches forming multiple CrCu layers on top of CrCu seed layer to serve as an adhesion enhancement layer by physical lock-in effect (Pag 1). Se-Young also teaches that the addition of these Cr-Cu layers increases the shear strength of the bump( Fig 9) after multiple reflows at 210C.
In the instant application ([0013]), it is disclosed that above 100degree C to 400C the Cr may migrate into Cu layers. In Se-Young, the reflow temperature is 210C, therefore and as Figure 1 shows, the Cr may be present in a second region of the Cu pillar.
Accordingly, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have a gradient of Cr-Cu in a second region of a copper pillar in the structure of Ha, as taught by Se-Young, to improve adhesion and increase shear strength of the bump under several high temperature reflow conditions.
Regarding Claim 2, while Ha is silent about a concentration gradient, Se-Young shows that the concentration of the Cr alloy closer to pure copper is lower. Specifically, TEM image in (e.g., Fig 1 (c) shows the concentration gradient.
Accordingly, it would have been obvious to one of ordinary skill in the art at the time the invention was filed to have extra layers of Cr-Cu in the first copper layer to increase shear strength of the bump under several reflow conditions.
Regarding Claim 3, Ha shows that the seed layer may contain copper alloyed with chromium, which is well known to have a negative standard electromotive force potential (-0.74).
Additionally, note that a limitation in a claim with respect to a material property in a claimed device does not differentiate the claimed device from prior-art device if the prior-art device teaches all the structural limitations in the claims.
As stated in Best, “Where the claimed and prior art products are identical or substantially identical in structure or composition, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F. 2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)
In this case, the instant application states in Par. [0026] that Cr has a negative standard EMF and thus are more reactive than copper to a wet etchant. The wet etchant may be, as in [0026], a solution including and/or containing at least water, hydrogen peroxide, and ammonium hydroxide, or a solution including and/or containing at least water, hydrogen peroxide, and phosphoric acid. Hence, the Chromium in the seed layer of Ha is capable of being more reactive to the wet etchant listed above.
Note that the applicant has a burden of proof once the examiner establishes a sound basis for believing that the products of the applicant and the prior art are the same. See In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed, Cir. 1990).
Regarding Claim 4, Ha shows one of the alloying elements to be Cr.
Regarding Claim 5, See comments from paragraph 15-16 from claim 2, as they would be considered repeated here.
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over in view of Ha/Se-Young further in view of Sakuma et al (US 20220208719 A1, Hereinafter Sakuma) .
Regarding Claim 6, while Ha/Se-Young show a UBM pillar with Cu and Nickel, it is silent about a layer of nickel on a first copper layer and a second copper layer on the nickel with a width of 5um-95um.
Sakuma (e.g., Fig 3, [0033]), on the other hand and in a related field of under bump structures, Teaches a Cu/Ni/Cu bump that is in a width of 5-30um. The first Cu is used to increase the pillar height, Ni is used as a barrier layer, and the second Cu is used to interface with a solder layer.
Accordingly, it would have been obvious to have an additional Ni and copper layer as nickel is a diffusion barrier layer, while Cu can be used to form an IMC with the solder.
Additionally, with regards to the particular width claimed, it is also noted that the specification fails to provide teachings about the criticality of having a width of solder pad between 5-95um and the courts have held that differences in (widths) will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such widths are critical. “Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the workable ranges by routine experimentation”. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Since the applicant has not established the criticality (see next paragraph below) of the claimed width, and since Sakuma teaches an arrangement of (widths) known in the art, it would have been obvious to one of ordinary skill in the art to use these widths in the device of Ha/Se-Young.
CRITICALITY: The specification contains no disclosure of either the critical nature of the claimed dimensions ratios or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions ratios or upon another variable recited in a claim, the applicant must show that the chosen ratios are critical. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1939 (Fed. Cir. 1990).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANEESA RIAZ BAIG whose telephone number is (571)272-0249. The examiner can normally be reached Monday-Friday 8am-5pm EST.
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/ANEESA RIAZ BAIG/
Examiner, Art Unit 2814 /WAEL M FAHMY/Supervisory Patent Examiner, Art Unit 2814
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