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 .
DETAILED ACTION
Election/Restrictions
Applicant’s election without traverse of Group I (claims 1-13) in the reply filed on 6/9/26 is acknowledged. Claims 14-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 6/9/26.
Title
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. (see MPEP § 606.01).
This may result in slightly longer titles, but the loss in brevity of title will be more than offset by the gain in its informative value in indexing, classifying, searching, etc.
The following title is suggested:
“Semiconductor Die with Nanotwinned Copper Bond Pad and Method of Forming”
because it more accurately identifies the subject matter of the application than the broad title “Die with Bond Pad.” The revised title specifies the semiconductor die, the distinguishing nanotwinned copper bond pad, and the claimed fabrication method. It is concise, technically descriptive, and consistent with the scope of the apparatus and method claims.
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.
Claims 1-6 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 20240395744) in view of Zhang et al. (US 20210313291), further in view of Lin et al. (US 20240038698), and further in view of Taylor et al (US 20010054557).
Regarding claim 1. Chen teaches A method for forming an IC (integrated circuit) package comprising:
Chen teaches a method of manufacturing a semiconductor device including providing a semiconductor wafer, forming a copper seed layer 130 (Fig 1B), and electrochemically plating a copper bond pad comprising nanotwinned copper having a preferred (111) crystal orientation [0032], [0032]-[0035]. Chen further teaches controlling the electroplating solution to produce the nanotwinned copper structure.
But Chen does not expressly teach singulating the semiconductor wafer, attaching the semiconductor die to a package substrate, wire bonding the copper bond pad with a copper wire, or forming a copper-to-copper bond.
However, Zhang teaches singulating the semiconductor wafer, attaching the semiconductor die to a package substrate, and assembling the semiconductor package after formation of the bond pads [0027]-[0029].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Zhang's conventional semiconductor packaging operations into Chen's process because singulation and die attachment are routine downstream manufacturing steps for producing a packaged semiconductor device.
But Chen in view of Zhang still does not expressly teach bonding a copper wire directly to the nanotwinned copper bond pad to form a copper-to-copper bond.
However, Lin teaches bonding a copper bonding wire directly to a nanotwinned copper bond pad by forming a copper ball bond and copper stitch bond (Fig 4A- Fig 4b, [0090]-[0091]), thereby producing a copper-to-copper bond while substantially avoiding intermetallic compound formation and improving bond reliability.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ Lin's copper wire bonding process in Chen's semiconductor package because doing so provides a reliable copper-to-copper interconnection having improved bonding characteristics.
But Chen in view of Zhang and Lin does not expressly teach forming the nanotwinned copper bond pad by pulse-current electroplating.
However, Taylor teaches pulse-current electroplating and explains that pulse waveform parameters, including duty cycle, pulse frequency, pulse duration, and current density, are controllable process variables that may be adjusted to control electroplating characteristics, including grain size, coating morphology, plating rate, current efficiency, and deposit properties. Taylor further teaches that pulse-current electroplating provides improved control over the deposited coating through adjustment of the pulse waveform.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute Taylor's pulse-current electroplating process for Chen's direct-current electroplating process because Taylor teaches that pulse-current electroplating provides improved control over deposit morphology and electroplating characteristics through adjustment of recognized process variables, thereby predictably improving control of the deposited copper structure.
Regarding claim 2. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1, Lin teaches encapsulating the semiconductor package with an encapsulant surrounding the conductive pads and conductive wire. Specifically, Lin discloses package structure 1 including encapsulant 60 surrounding substrates 10 and 100, conductive pads 200 and 200A, and conductive wire 300 (Lin, ¶¶0026-0035, Figs. 1 and 1A). Lin further teaches that encapsulant 60 encapsulates the conductive pads and conductive wire and may comprise an epoxy resin, molding compound, polyimide, phenolic material, silicone-containing material, or combinations thereof (Lin, ¶0035). Lin additionally teaches that the encapsulant includes a resin layer 610 and fillers 620 dispersed therein (Lin, ¶0045).
Regarding claim 3. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1, Chen teaches performing an electroplating process using an electroplating solution containing about 180 g/L to about 210 g/L copper sulfate pentahydrate together with sulfuric acid, hydrochloric acid, and other additives, wherein the electrolyte composition is controlled such that the deposited copper grows as nanotwinned copper having a preferred (111) orientation.
One of ordinary skill in the art would have understood that the disclosed concentration of copper sulfate pentahydrate corresponds to an elemental copper concentration of approximately 46 g/L to about 53 g/L, which falls within the claimed copper concentration range of about 32 g/L to about 60 g/L. Therefore, Chen teaches a plating solution having the claimed copper concentration.
Furthermore, Chen teaches controlling the electrolyte composition to produce the desired nanotwinned copper deposit having a preferred (111) orientation. Accordingly, it would have been obvious to employ a copper concentration within the claimed range because electrolyte copper concentration is a recognized result-effective variable affecting electroplating characteristics, and selecting an appropriate concentration within the known operating range would have been a matter of routine optimization.
Regarding claim 4. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1, Chen teaches controlling the composition of the electroplating solution to obtain nanotwinned copper having the desired (111) crystal orientation by controlling the electrolyte recipe during electroplating.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the copper concentration to a value of about 55 g/L to about 60 g/L, since electrolyte copper concentration is a recognized result-effective variable affecting electroplating performance, including deposition characteristics and crystal growth. Selecting a concentration near the upper end of the known operating range to achieve the desired deposition characteristics would have amounted to nothing more than routine optimization of a known process parameter.
Applicant has not demonstrated that the claimed subrange is critical or produces unexpected results relative to neighboring concentrations.
Regarding claim 5. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1, Taylor teaches that duty cycle is a controllable parameter of the pulse-current waveform and defines both cathodic and anodic duty cycles. Taylor further teaches that duty cycle, together with pulse frequency, current density, and pulse duration, is adjusted to control electroplating characteristics, and that modifying the pulse waveform controls grain size and coating morphology.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select a duty cycle of about 25% through routine optimization because duty cycle is a recognized result-effective variable affecting deposition characteristics, grain morphology, and coating properties in pulse-current electroplating.
Regarding claim 6. Chen in view of Zhang, Lin and Taylor discloses The method of claim 5, Taylor teaches that pulse-current electroplating may be performed using frequencies from about 5 Hz to about 700 Hz, with preferred frequencies from about 10 Hz to about 200 Hz.
Accordingly, Taylor expressly teaches a pulse frequency encompassing the claimed value of about 5 Hz. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a pulse frequency of about 5 Hz because pulse frequency is a recognized process parameter adjusted to control electroplating characteristics and deposition performance.
Regarding claim 9. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1, But Chen in view of Zhang, further in view of Lin, and further in view of Taylor does not expressly teach that the copper-to-copper bond has a bonding area of about 70% to about 95%, as recited in claim 9.
However, Lin teaches directly bonding a copper wire to a nanotwinned copper conductive pad to form a copper-to-copper metallurgical bond having improved bonding characteristics and reliability.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the wire-bonding process to obtain an appropriate copper-to-copper bonding area because the extent of the bonded interface is a result-effective variable that is directly affected by known wire-bonding parameters, including bonding force, ultrasonic energy, bonding temperature, and bonding time. Routine optimization of these known process parameters to achieve reliable electrical and mechanical bonding would have predictably resulted in a bonding area within the claimed range.
Furthermore, the instant specification does not attribute any criticality or unexpected results to the claimed bonding area of about 70% to about 95%. Accordingly, selecting a bonding area within the claimed range would have been an obvious matter of routine optimization.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 20240395744) in view of Zhang et al. (US 20210313291), further in view of Lin et al. (US 20240038698), further in view of Taylor et al (US 20010054557), and further in view of Mirkarimi (US 20220285303).
Regarding claim 7. Chen in view of Zhang, Lin and Taylor discloses The method of claim 1. But Chen in view of Zhang, Lin and Taylor does not expressly disclose wherein the nanotwin copper bond pad of the wafer has a thickness of about 6 micrometers to about 15 micrometers and a width of about 15 micrometers to about 55 micrometers.
Mirkarimi teaches a conductive feature, such as a contact pad, having a thickness in a range of about 0.3 μm to about 6 μm and a width in a range of about 0.3 μm to about 60 μm, including widths of about 0.5 μm to about 40 μm and 0.5 μm to about 20 μm, thereby teaching conductive bond pad dimensions encompassing the claimed bond pad width. Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the nanotwinned copper bond pad of Chen to have dimensions as taught by Mirkarimi because the thickness and width of a bond pad are recognized design parameters selected according to the intended semiconductor package, package layout, current-carrying requirements, and wire-bonding reliability. Optimizing such dimensions to satisfy the design requirements of a particular semiconductor package would have been a matter of routine engineering judgment that would have yielded predictable results.
Therefore, it would have been obvious to provide the nanotwinned copper bond pad of Chen in view of Zhang, Lin and Taylor with a bond pad width within the range taught by Mirkarimi and to optimize the bond pad thickness to the claimed range to achieve the desired package design and bonding performance. Accordingly, claim 7 would have been obvious over Chen in view of Zhang, further in view of Lin, further in view of Taylor, and further in view of Mirkarimi.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 20240395744; hereinafter Chen-744) in view of Zhang et al. (US 20210313291), further in view of Lin et al. (US 20240038698), further in view of Taylor et al (US 20010054557), and further in view of Chen et al. (US 20050142374; hereinafter Chen-374)
Regarding claim 8. Chen-744 in view of Zhang, Lin and Taylor discloses The method of claim 1. But Chen-744 in view of Zhang, Lin and Taylor does not expressly disclose further comprising applying an anti-tarnish coating on the wafer responsive to the electroplating.
However, Chen-374 teaches performing a conventional post-treatment after copper deposition, including forming an anti-tarnishing layer (also referred to as an anti-oxidation layer) over the copper surface to improve oxidation resistance. Specifically, Chen teaches sequentially forming a nodulation layer, a barrier layer, an anti-tarnishing (anti-oxidation) layer, and an adhesion-promotion layer after copper deposition.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the anti-tarnish coating taught by Chen-374 to the nanotwinned copper bond pad of Chen-744 in view of Zhang, Lin and Taylor because exposed copper surfaces are susceptible to oxidation, and protecting the copper surface from oxidation preserves the surface condition for subsequent bonding processes and improves the reliability of the resulting electrical interconnection. Applying a conventional anti-tarnish treatment to an exposed copper bond pad would have been a predictable use of a known technique to improve the durability and bondability of the copper surface.
Accordingly, claim 8 would have been obvious over Chen-744 in view of Zhang, further in view of Lin, further in view of Taylor, and further in view of Chen-374.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 20240395744) in view of Zhang et al. (US 20210313291), further in view of Lin et al. (US 20240038698), and further in view of Taylor et al (US 20010054557).
Regarding claim 10. Chen discloses A method for forming an IC (integrated circuit) package comprising:
Chen teaches a semiconductor package including a semiconductor structure having embedded circuitry and an electroplated conductive feature substantially composed of highly textured nanotwinned copper (NT-Cu). Chen further teaches that the electroplated conductive feature has a preferred (111)-oriented crystal structure, as confirmed by electron backscatter diffraction (EBSD) analysis (Chen, ¶¶0031-0035 and ¶0076, Figs. 1A-2B, 6, and 21A-21B). Chen further teaches incorporating the electroplated NT-Cu conductive feature into a semiconductor package.
But Chen does not expressly disclose a Cu wire directly bonded to the electroplated NT-Cu bond pad.
However, Zhang teaches conventional semiconductor package assembly in which a semiconductor die is mounted onto a package interconnect or leadframe and electrically connected to package leads through wire bonding.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the package structure of Chen in view of the teachings of Zhang by incorporating the conventional package assembly taught by Zhang because doing so would have provided a known semiconductor package architecture suitable for utilizing Chen's electroplated NT-Cu conductive feature.
But Chen in view of Zhang does not expressly teach directly bonding a Cu wire to the electroplated NT-Cu bond pad.
However, Lin teaches a semiconductor package including an NT-Cu conductive pad directly bonded to a Cu conductive wire. Lin specifically teaches that the ball bond directly contacts the NT-Cu pad and that the stitch bond directly contacts another NT-Cu pad (Lin, ¶¶0029-0034, Figs. 1, 1A, and 2A). Lin further teaches that the Cu wire and NT-Cu pad form a Cu-to-Cu diffusion bond substantially free of intermetallic compounds and having improved bond strength, electrical performance, and package reliability (Lin, ¶¶0085-0088).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to further modify the package structure of Chen, as modified by Zhang, in view of the teachings of Lin by directly bonding the Cu wire to the electroplated NT-Cu bond pad because Lin teaches that such a Cu-to-NT-Cu diffusion bond improves diffusion bonding, bond strength, oxidation resistance, and package reliability while substantially eliminating intermetallic compound formation.
Accordingly, it would have been obvious to modify the package structure of Chen in view of Zhang and Lin to obtain the claimed semiconductor package.
Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 20240395744) in view of Zhang et al. (US 20210313291), further in view of Lin et al. (US 20240038698), and further in view of Mirkarimi (US 20220285303).
Regarding claim 11. Chen in view of Zhang and Lin The method of claim 10. Chen in view of Zhang and Lin does not expressly disclose wherein the nanotwin copper bond pad has a thickness of about 6 micrometers to about 15 micrometers.
However, Chen-744, in view of Zhang, further in view of Lin, and further in view of Taylor, does not teach that the nanotwinned copper bond pad has a thickness of about 6 micrometers to about 15 micrometers, as recited in claim 11.
Mirkarimi teaches a conductive feature, such as a contact pad, having a thickness in a range of about 0.3 μm to about 6 μm.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to select a bond pad thickness of about 6 μm to about 15 μm because bond pad thickness is a recognized design parameter selected according to the intended semiconductor package, current-carrying requirements, mechanical strength, and wire-bonding reliability. Routine optimization of the bond pad thickness to satisfy the design requirements of a particular semiconductor package would have yielded predictable results. Accordingly, it would have been obvious to provide the nanotwinned copper bond pad with the claimed thickness.
Regarding claim 12. Chen in view of Zhang, Lin and Mirkarimi discloses The method of claim 11, Mirkarimi teaches a conductive feature, such as a contact pad, having a width in a range of about 0.3 μm to about 60 μm, including widths of about 0.5 μm to about 40 μm and about 0.5 μm to about 20 μm, thereby encompassing the claimed width range. Accordingly, it would have been obvious to provide the nanotwinned copper bond pad of Chen-744 with a width of about 15 μm to about 55 μm, as recited in claim 12.
Regarding claim 13. Chen in view of Zhang and Lin The method of claim 10. But Chen-744, in view of Zhang, further in view of Lin, and further in view of Taylor, does not expressly teach that the copper-to-copper bond has a bond area of about 70% to about 95% of an interface between the bond wire and the nanotwinned copper bond pad, as recited in claim 13.
However, Lin teaches directly bonding a copper wire to a nanotwinned copper conductive pad to form a reliable copper-to-copper metallurgical bond having improved bonding characteristics.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to optimize the wire-bonding process to obtain an appropriate bond area because the extent of the bonded interface is a result-effective variable that is directly influenced by known wire-bonding parameters, including bonding force, ultrasonic energy, bonding temperature, and bonding time. Routine optimization of these known process parameters to achieve reliable electrical and mechanical bonding would have predictably resulted in a bond area within the claimed range.
Furthermore, the instant specification does not attribute any criticality or unexpected results to the claimed bond area of about 70% to about 95% of the interface between the bond wire and the nanotwinned copper bond pad. Accordingly, selecting a bond area within the claimed range would have been an obvious matter of routine optimization.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Changhyun Yi whose telephone number is (571)270-7799. The examiner can normally be reached Monday-Friday: 10A-3P.
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/Changhyun Yi/Primary Examiner, Art Unit 2812
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