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 with traverse of a system for etching wafer in the reply filed on May 11, 2026 is acknowledged. The traversal is on the ground(s) that the controller interface and operations performed by the controller are special technical features. This is not found persuasive because Koshimizu (US 2020/0273670) teaches the required controller and associated operations are not special.
The requirement is still deemed proper and is therefore made FINAL.
Claims 15-20 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on May 11, 2026.
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.
Claims 1-14 are rejected under 35 U.S.C. 103 as being unpatentable over Sriraman (US 2017/0018411) in view of Dhindsa (US 2009/0071938) and Koshimizu (US 2020/00273670).
Regarding claim 1, Sriraman teaches a system for etching a wafer, the system comprising:
a lower electrode (104) and an upper electrode (109) disposed above the lower electrode;
an edge ring (200) surrounding the lower electrode (104);
a first radio frequency (RF) generator (111) electrically coupled to the lower electrode and a second radio frequency (RF) generator (204) electrically coupled to the edge ring (200, 202, fig. 2a);
and a controller (1400, fig. 14, [0116]) interfaced with the first (111) and second (204) RF generators and the DC bias generator, the first RF generator (111) is configured to produce a wafer voltage (Vw) waveform at the lower electrode, the produced Vw waveform includes an induced direct current (DC) component and a first RF component produced by the first RF generator ([0109]),
wherein the controller (1400, fig. 14, [0116]) is configured to produce an edge ring voltage (VER) waveform for application to the edge ring, the VER waveform includes additive DC bias and a second RF component produced by the second RF generator [0109],
wherein the VER waveform is programmed by the controller to have a substantially same frequency (10 MHz)and phase ([0058]) as the Vw waveform, a DC offset (100V) from the Vw waveform, and an amplitude variation relative to an amplitude of the Vw waveform (pulsed, [0078]).
Sriraman does not teach a direct current (DC) bias generator for electrically supplying an additive DC bias to the edge ring. Nor does it teach a controller interfaced with the first and second Rf generators and the DC bias generator.
Dhindsa is directed to a plasma etching system that provides Rf bias power to a substrate electrode and RF and Dc power to an edge ring to control the ion trajectory at the edge area of the wafer. Dhindsa teach a direct current (DC) bias generator for electrically supplying an additive DC bias to the edge ring ([0043] [0062-0063]).
Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the edge ring of Sriraman by providing a direct current (DC) bias generator for electrically supplying an additive DC bias to the edge ring, as taught by Dhindsa, because it would allow the ion energy on the substrate to be controlled independently [0063].
Koshimizu is directed to an etching system that provides a DC + RF power to an edge ring and teaches RF power to a substrate bias electrode to perform etching of a wafer. It teaches a controller 200 interfaced with the first (48) and second (90) RF generators and the DC bias generator)50; [0073], [0131]). Because Koshimizu teaches the required controller is operable it would have been obvious to one of ordinary skill in the art at the time of invention to have used the required controller as the controller in Sriraman with a reasonable expectation of success. The rationale to support a conclusion that the claim would have been obvious is that all the claimed elements were known in the prior art and one skilled in the art could have combined the element by known methods with no change in their respective functions and the combination yielded nothing more than predictable results to one of ordinary skill in the art. MPEP 2143.A.
Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the controller of Sriraman by providing a controller interfaced with the first and second RF generators and the DC bias generator, as taught by Koshimizu, because all the claimed elements were known in the prior art and one skilled in the art could have combined the element by known methods with no change in their respective functions and the combination yielded nothing more than predictable results to one of ordinary skill in the art. MPEP 2143.A.
Regarding claim 2, the Examiner takes the position that “a ratio of applied edge ring voltage to applied wafer voltage (VAER/VAw) changes during application of the VER waveform” is a functional recitation of the apparatus of claim 1 that does not require additional structure. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches various voltages of 100V, 300 V, 500 V or 700 V were applied to the annular electrode 202 and a voltage of 200 V applied to the bias electrode 104 (pg. 7, ln. [0098-0100]. Therefore Sriraman teaches an apparatus performing the function required by claim 2. See MPEP 2114 and 2115.
Regarding claim 3, the Examiner takes the position that “said changes in the VAER/VAw ratio causes a change in ion tilt and ion tilt spread near an edge of the wafer and proximate to said edge ring during said etching” is a functional recitation of the apparatus of claim 1, that doesn’t require additional structure. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches at various voltages of 100V, 300 V, 500 V or 700 V were applied to the annular electrode 202 and a voltage of 200 V applied to the bias electrode 104 (pg. 7, ln. [0098-0100]) causes a change in ion tilt and ion tilt spread near an edge of the wafer and proximate to said edge ring during said etching (Fig. 4a-4e). Therefore Sriraman teaches an apparatus performing the function required by claim 3. See MPEP 2114 and 2115.
Regarding claim 4, the Examiner takes the position that “said ion tilt is an incidence angle that is other than normal to a surface of the wafer, or normal to the surface of the wafer” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches the apparatus performing the function required by claim 4. See Fig. 4a-4e, [0098].
Regarding claim 5, the Examiner takes the position that “said incidence angle includes a negative angle or a positive angle, or a combination thereof, said ion tilt having the positive angle tilts in a direction away from a center point of the wafer, said ion tilt having the negative angle tilts in a direction toward the center of the wafer” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches the apparatus performing the function required by claim 5. See Fig. 4a-4e, [0098].
Regarding claim 6, the Examiner takes the position that “said VAER/VAw ratio has a value ranging from about 0.3 to 0.7” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches the apparatus performing the function required by claim 6 [0098]-[0100].
Regarding claim 7, the Examiner takes the position that “additive DC bias causes the change in the ion tilt near the edge of the wafer and proximate to said edge ring during said etching” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so. Sriraman teaches the difference in DC bias causes the change in ion tilt near the edge of the wafer and proximate to said edge ring during said etching [0098-0100] Fig. 4a-4e)
Sriraman does not teach additive DC bias causes the change in the ion tilt near the edge of the wafer and proximate to said edge ring during said etching.
Dhindsa teaches the additive DC bias causes the change in the ion tilt near the edge of the wafer and proximate to said edge ring during said etching ([0041-0043][0062]).
Therefore it would have been obvious to one of ordinary skill in the art at the time of the invention to modify the edge ring of Sriraman by providing each additive DC bias causes the change in the ion tilt near the edge of the wafer and proximate to said edge ring during said etching, as taught by Dhindsa, because it would allow the ion energy on the substrate to be controlled independently [0063].
Regarding claim 8, the Examiner takes the position that “application of the Vw waveform and the VER waveform during said etching causes a plasma sheath that is defined over the wafer and the edge ring, a portion of the plasma sheath that is defined over the wafer is substantially coplanar with a portion of the plasma sheath defined over the edge ring” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so.
Sriraman teaches application of the Vw waveform and the VER waveform during said etching causes a plasma sheath that is defined over the wafer and the edge ring [0016],
a portion of the plasma sheath (302) that is defined over the wafer (105) is substantially coplanar with a portion of the plasma sheath (302) defined over the edge ring (202, [0097], Fig. 3b).
Regarding claim 9, the Examiner takes the position that “the application of the Vw waveform and the VER waveform during said etching reduces ion tilt near an edge of the wafer, said reduction in the ion tilt causes one or more ions to be substantially normal to a top surface of the wafer” is a functional recitation of the apparatus of claim 1 without requiring additional structure. See MPEP 2114 and 2115. The apparatus of Sriraman would have the capability to perform this function because it teaches all the necessary structure for doing so.
Sriraman teaches the application of the Vw waveform and the VER waveform during said etching reduces ion tilt near an edge of the wafer, said reduction in the ion tilt causes one or more ions to be substantially normal to a top surface of the wafer ([0097-0100], Fig. 3b, Fig. 4a-4e).
Regarding claim 10, the Examiner takes the position that a first distance extending from a top surface of the wafer to a lower edge of the plasma sheath makes reference to materials worked upon by the apparatus such as the plasma sheath and wafer. Therefore claim 10 has been considered but does not receive patentable weight. See MPEP 2114 and 2115. Sriraman teaches the apparatus capable of performing as recited by claim 10.
Regarding claim 11, Sriraman teaches a top surface of the wafer (105) is disposed below a top surface of the edge ring (200), or at a substantially same elevation to the top surface of the edge ring, or below the top surface of the edge ring (Fig. 3b), 0087]).
Regarding claim 12, Sriraman teaches the DC offset from the Vw waveform (200 V) has a magnitude value ranging about 500 V to 1,000 V ([0098],[0100]).
Regarding claim 13, Sriraman teaches a frequency operation of the first RF generator and the second RF generator is about 400 kHz [0057],[0073] because it teaches each Rf generator to have the capability of operating at this frequency.
Regarding claim 14, Sriraman teaches a third radio frequency (RF) generator (121, Fig. 1b) electrically coupled to the upper electrode (109).
Sriraman teaches that higher voltages are gained by using low RF frequencies while high plasma densities can be achieved by using higher RF frequencies [0060]. Therefore the prior art teaches that frequency operation is a result effective variable.
It would have been obvious to one having ordinary skill in the art at the time the invention was made to provide “a frequency operation of the third RF generator is greater than the frequency operation of the first generator and the second generator” since 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).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JOHN J BRAYTON whose telephone number is (571)270-3084. The examiner can normally be reached 9AM-5PM EST M-F.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, James Lin can be reached at 571 272 8902. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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JOHN J. BRAYTON
Primary Examiner
Art Unit 1794
/JOHN J BRAYTON/Primary Examiner, Art Unit 1794
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