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 .
Response to Arguments
Applicant’s arguments, see Pgs. 1-5, filed 03/26/2026, with respect to the rejection(s) of claim(s) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Geefay et al. (US 20040198040), herein Geefay.
Claims 1-3 and 8-20 are pending, with claim 1 being amended in the response dated 03/26/2026.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3, 8-12, and 18-20 are rejected under 35 U.S.C. 103 as being unpatentable over Chiu et al. (CN 107579032 A) [IDS dated:11/20/2023], herein Chiu, in view of Shen (US 20130249095 A1) [IDS dated: 11/20/2023], Geefay et al. (US 20040198040 A1), herein Geefay.
US 20200152445 A1 [IDS dated 11/20/2023] is used as the English language equivalent to CN 107579032 B. The citations herein refer to US 20200152445 A1.
In regards to claims 1 and 8, Chiu teaches a backside metallization of a semiconductor device [0002, 0004]. The backside metalized compound semiconductor wafer having front and back surfaces in which a ground pad is formed on the front surface and a via is present that extends from the backside to the below the pad [0004, 0028, Fig. 1]. The backside metallization layers are formed on the backside of the wafer and coat the walls of the via and electrically connect the pad to the backside metallization layers [0004, Fig. 1]. The metallization layers comprise an adhesion layer formed first on the surface of the layer [0029, Fig. 1]. A seed layer is formed on the adhesion layer [0030, Fig. 1]. A gold layer formed on the seed layer [0030, Fig, 1]. Chiu further teaches the gold layer has a thickness in the range of 0.5 µm to 25 µm [0030]. This overlaps the claimed range. Chiu further teaches the adhesion layer contains a sublayer of a nickel vanadium material and an alloy sublayer of titanium tungsten material [0011-0012, 0016, 0027, 0029]. The thickness of the titanium tungsten material is 2 nm to 10 nm [0029].
Chiu does not teach that a copper layer is further formed on the gold layer.
Shen teaches metal plating layers across and within a via in a semiconductor wafer to create a device [Abstract, Fig 5H]. A through-wafer via electrically contacts a pad on the other surface of the wafer [Abstract, Fig. 5H]. Shen teaches multiple metals layers formed across and within the via include a barrier/adhesion layer which may be a nickel vanadium alloy, a seed layer of gold, and a final contact layer of copper and/or gold [0044, 0060, 0063-0065].
Shen expressly teaches that a copper layer may replace some or all of the gold contact layer [0060]. Shen further teaches gold is difficult to solder thus the final contact layer is preferably copper [0052]. Shen teaches the final copper layer is deposited by electroplating [0065]. Shen teaches the thickness of the copper layer may simply coat the walls or may nearly fill the via [0065]. This overlaps the claimed range.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have added the outer final electroplated copper contact layer of Shen to the metal layers of Chiu. One would have been motivated to do so in order for the back surface to be more easily soldered for further attachment.
Chiu does not teach that the via has a width that gradually increases from said front surface of the substrate to the back surface of the substrate.
Geefay teaches sloped via contacts [Abstract, Fig. 3E]. The via is wider at the back of wafer than at the front [0016].
Geefay teaches that the sloped walls allow for easy access to the inside walls of the for metal sputtering or plating [Abstract, 0005-0006].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have created the via of Chiu with sloped sidewalls as taught by Geefay. One would have been motivated to do so based on the improvement of the coating of the subsequent metal layers.
Modified Chiu discloses the claimed invention except for the range of the thickness of the titanium tungsten layer. It would have been obvious to one having ordinary skill in the art at the time the invention was made to the thickness from 0.02 µm to 0.1 µm, since such a modification would have involved a mere change in the size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
Modified Chiu discloses the claimed invention except for giving an exact range for the electroplated copper layer thickness. It would have been obvious to one having ordinary skill in the art at the time the invention was made to the thickness from 0.2 to 5 µm, since such a modification would have involved a mere change in the size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
In regards to claims 2-3, Chiu further teaches the adhesion layer contains a sublayer of a nickel vanadium material [0011-0012, 0016, 0027, 0029]. The layer has a thickness ranging from 3 nm to 200 nm [0027]. This overlaps the claimed range. The layer includes nickel in an amount ranging from 90 wt % to 97 wt % and vanadium in an amount ranging from 3 wt % to 10 wt %, based on a total weight of the adhesion layer [0027].
As set forth in MPEP 2144.05, in the case where the claimed range “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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
In regards to claim 9, modified Chiu teaches the limitations of claim 8 as set forth above. Chiu further teaches the adhesion layer contains a sublayer of a nickel vanadium material and an alloy sublayer of titanium tungsten material [0011-0012, 0016, 0027, 0029]. The layer has a thickness ranging from 3 nm to 200 nm [0027]. This overlaps the claimed range.
In regards to claim 10, Chiu further teaches the substrate has a thickness ranging from 70 to 120 µm [0028].
In regards to claim 11, Chiu further teaches the seed layer is gold [0030].
In regards to claim 12, Chiu further teaches the seed layer has a thickness in the range of 10 nm to 250 nm ( [0030]. This overlaps the claimed range.
In regards to claims 18-19, Chiu further teaches the substrate is gallium arsenide [0036].
In regards to claim 20, Chiu further teaches the ground pad structure is in contact with the metal layered structure that extends into the via [0004, Fig. 1].
Claims 13-17 are rejected under 35 U.S.C. 103 as being unpatentable over Chiu et al. (CN 107579032 A) [IDS dated: 11/20/2023], herein Chiu, in view of Shen (US 20130249095 A1) [IDS dated: 11/20/2023], as applied to claim 1 above, and further in view of Chen et al. (US 20130277845) [IDS dated: 11/20/2023]., herein Chen.
In regards to claim 13, modified Chiu does not teach that an anti-oxidation layer is formed on the electroplated copper layer.
Chen teaches a backside metallization process for semiconductor devices wherein a via on the backside is in electrical contact with a pad/active layer on the front side of a substrate [Abstract, 0013-00021, Figs. 2A-D]. The layers from the substrate include, a backside metal seed layer, at least one thermal expansion buffer layer, a backside metal layer which is copper, and at least one oxidation resistant layer [0006-0009].
Chen teaches the copper backside metal layer is prone to oxidization thus an oxidization resistant layer is deposited to cover the copper layer [0002, 0008-0010. 0032].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have added the outer oxidization resistant layer of Chen to the outer electroplated copper layer of modified Chiu. One would have been motivated to do so in to prevent the oxidation of the copper layer.
In regards to claim 14, modified Chiu teaches the limitations of claim 13 as set forth above. Chen further teaches the antioxidant layer comprises nickel vanadium [0010, claim 10]. Chen does not teach the thickness of the layer.
Modified Chiu discloses the claimed invention except for the thickness range of the oxidation resistant layer. It would have been obvious to one having ordinary skill in the art at the time the invention was made to the thickness from 0.03 to 0.2 µm, since such a modification would have involved a mere change in the size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
In regards to claim 15, modified Chiu teaches the limitations of claim 13 as set forth above. Chen further teaches the antioxidant layer comprises palladium [0010, claim 10].
In regards to claim 16, modified Chiu teaches the limitations of claim 15 as set forth above. Chen further teaches the antioxidant layer comprises Pd [0010, claim 10]. Chen teaches the oxidation resistant layer is made of at least one layer [0032].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have used more than one layer in the oxidation resistant layer as taught by Chen. One would have been motivated to do so based on the additionally benefits that are granted by the combination of layers.
Chen does not teach the thickness of the layer.
Modified Chiu discloses the claimed invention except for the thickness range of the oxidation resistant layer. It would have been obvious to one having ordinary skill in the art at the time the invention was made to the thickness from 0.02 to 0.1 µm, since such a modification would have involved a mere change in the size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
In regards to claim 17, modified Chiu teaches the limitations of claim 13 as set forth above. Chen further teaches the antioxidant layer comprises gold [0010, claim 10]. Chen teaches the oxidation layer is made of at least one layer [0032].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to have used more than one layer in the oxidation resistant layer as taught by Chen. One would have been motivated to do so based on the additionally benefits that are granted by the combination of layers.
Chen does not teach the thickness of the layer.
Modified Chiu discloses the claimed invention except for the thickness range of the oxidation resistant layer. It would have been obvious to one having ordinary skill in the art at the time the invention was made to the thickness from 0.05 to 0.5 µm, since such a modification would have involved a mere change in the size of a component. A change in size is generally recognized as being within the level of ordinary skill in the art. Gardner v. TEC Systems, Inc., 725 F.2d 1338, 220 USPQ 777 (Fed. Cir. 1984), cert. denied, 469 U.S. 830, 225 USPQ 232 (1984).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ELIZABETH A COLLISTER whose telephone number is (571)270-1019. The examiner can normally be reached Mon.-Fri. 9 am-5 pm.
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/ELIZABETH COLLISTER/Primary Examiner, Art Unit 1784
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