Patent Application 17978601 - CLEANING METHOD SUBSTRATE PROCESSING METHOD AND

Title: CLEANING METHOD, SUBSTRATE PROCESSING METHOD AND PLASMA PROCESSING APPARATUS

Application Information

Invention Title: CLEANING METHOD, SUBSTRATE PROCESSING METHOD AND PLASMA PROCESSING APPARATUS
Application Number: 17978601
Submission Date: 2025-05-19T00:00:00.000Z
Effective Filing Date: 2022-11-01T00:00:00.000Z
Filing Date: 2022-11-01T00:00:00.000Z
National Class: 216
National Sub-Class: 067000
Examiner Employee Number: 73018
Art Unit: 1713
Tech Center: 1700

Rejection Summary

102 Rejections: 0
103 Rejections: 2

Cited Patents

The following patents were cited in the rejection:

US 0241412🔗
US 0006351🔗

Office Action Text

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 .

Drawings
The drawings were received on April 30, 2025. These drawings are acceptable.

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, 6-9 and 13-17 are rejected under 35 U.S.C. 103 as being unpatentable over Jun et al (US 2012/0006351 A1) in view of Murakami et al (US 2012/0241412 A1).
Jun discloses a cleaning method in a plasma processing apparatus 100 for plasma processing a substrate W (see abstract), the method comprising:
forming a plasma P [0055]-[0056] in a chamber 110 (Fig. 1, [0029], [0033]) of the plasma processing apparatus while a substrate is not being held in place [0047], [0071] by an electrostatic chuck 120 in the chamber;
supplying voltage 121 [0059] to the electrostatic chuck while plasma is being formed in (a).
Jun fails to explicitly disclose that the voltage supplied to the electrostatic chuck also reduces charge on a surface of the electrostatic chuck. Jun discloses the same method as in the instant invention, and therefore the same results are expected. Thus, reducing voltage is considered inherent in the method of Jun.
Jun plasma processes substrates [0043], and then cleans the electrostatic chuck and chamber by applying voltage, either positive (Fig. 3) or negative (Fig. 4), to the electrostatic chuck. This is the same method as in the instant invention. Therefore, the same results of “reducing charge on a surface of the electrostatic chuck,” to at least some degree, are expected in the method of Jun as in the instant claimed invention.
As to amended claim 1, Jun fails to disclose the order of (i) supplying plasma power, (ii) supplying voltage to the electrostatic chuck, (iii) turning the voltage off, and then (iv) stopping plasma power supply. Jun merely states to supply plasma power [0055] and to supply voltage [0059] to the electrostatic chuck (see also claim 1 of Jun which recites to supply a process gas, generate plasma, and apply voltage to the ESC, which suggests the cited order).
However, even absent this explicit teaching in Jun, it is obvious to first supply power and then supply voltage. It is also obvious to stop the voltage and then stop the plasma power.
Murakami generally teaches and suggests a useful technique, including the relative timing, for supplying power for forming plasma, supplying process gas, and starting supply of voltage to an electrode. More specifically, Murakami teaches to first supply the process gas and then supply the power for forming plasma [0035]. Thereafter, Murakami starts supply of a DC voltage, which although it is supplied to an upper electrode 4 [0035], suggests the cited order as claimed for supplying DC voltage to the electrostatic chuck.
[0035] Upon beginning the cleaning process, as depicted in FIG. 4, a surface of the susceptor 3 is exposed to a plasma processing region. Furthermore, reaction products A generated during the etching process adhere to the vicinities of a wafer mounting area of the susceptor 3 such as the inner wall of the vacuum chamber 1 and the ring member 22. In accordance with the present illustrative embodiment, since the CF-based or CHF-based gas is used as the processing gas, reaction products A mainly made of polymer adhere to the inside of the vacuum chamber 1. With the wafer mounting area of the susceptor 3 exposed, i.e., without mounting a dummy wafer on the susceptor 3, the cleaning gas such as an O.sub.2 gas is supplied into the vacuum chamber 1 from the cleaning gas supply source 6 at a preset flow rate of, e.g., about 700 sccm (standard cc/min.). Furthermore, an Ar gas is also supplied into the vacuum chamber 1 from the Ar gas supply source 8 at a preset flow rate of, e.g., about 700 sccm. Then, the internal pressure of the vacuum chamber 1 is set to, e.g., about 400 mTorr, and a high frequency power of, e.g., about 40 MHz for plasma generation is applied at a preset power level of, e.g., about 800 W. Then, a DC voltage ranging from, e.g., about -200 V to about -320 V is applied to the upper electrode 4 from the variable DC power supply 47. The cleaning gas (O.sub.2 gas) is excited into plasma by the high frequency power, and the polymer A as deposits adhering to the inside of the vacuum chamber 1 are ashed by oxygen radicals or ions and removed from the vacuum chamber 1 to the outside. The cleaning process is performed for, e.g., about 1 minute.

In other words, Murakami fairly teaches the following order: supply process gas, start plasma power, start chuck voltage for the case when a DC voltage is supplied to the ESC as opposed to an upper electrode (see Jun, Fig. 5 supplying voltage 160 to upper electrode [0079] compared to Fig. 3-4, which has supplying voltage 121a,b to ESC).
Jun fails to explicitly disclose stopping the stopping ESC voltage and then stopping plasma power. However, this order is suggested because there are only two options – the cited order, or the opposite order, i.e., stopping plasma power before stopping supply of voltage. A skilled artisan would be able to determine which option works best according to the cleaning process effect desired for the ESC or the interior of the chamber.
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to provide and then stop plasma power and chuck voltage in the order cited in claim 2 in the method of Jun because Murakami fairly teaches the cited order, and such is expected to give the predictable result of a clean electrostatic chuck and process chamber. While Murakami does not teach the order of stopping, such is an obvious matter of design choice because the steps are within the scope of one skilled in the art to determine the best order for efficient shut down.
Further, as to claim 3, Jun discloses that (a) includes supplying 140, 141 processing gas [0053] for forming plasma. Further, Jun discloses to supply process gas into the chamber [0053], and then to generate plasma from the supply gas [0055].
Jun fails to explicitly disclose stopping the supply of process gas after stopping the supply of voltage to the electrostatic chuck in (b). However, this order is suggested because there are only two options – the cited order, or the opposite order, i.e., stopping supply of gas before stopping supply of voltage. A skilled artisan would be able to determine which option works best according to the cleaning process effect desired for the ESC or the interior of the chamber.
It would have been obvious to one with ordinary skill in the art before the effective filing date of the claimed invention to provide and then stop the supply gas and chuck voltage in the order cited in claim 3 in the modified method of Jun because such is an obvious matter of design choice because the steps are within the scope of one skilled in the art to determine the best order for efficient shut down.
As to claims 6-8, Jun discloses to clean the surface of the electrostatic chuck ([0074], Fig.3) and an interior of the chamber ([0072], Fig.4).
As to claim 9, Jun fails to disclose relative values of the voltage supplied to the electrostatic chuck in steps (b1) and (b2). However, there are a limited number of choices. The values are expected to be different because different results are created, i.e., cleaning the chamber compared to cleaning the electrostatic chuck. In addition, one of ordinary skill in the art:
would recognize that there is a design need to vary the voltage,
there are a finite number of solutions, either the same or different voltages, and
could have pursued the known potential options with a reasonable expectation of success. For example, varying the voltage to get different results, or maintaining the voltage to get different results, is within the scope of one skilled in the art to determine which option provides the desired cleaning results.
Therefore, the claim would have been obvious because a person of ordinary skill has good reason to pursue the known options with his or her technical grasp, that is, they are obvious to try. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense. See MPEP 2143 E.
As to claims 13-17, see the rejection of claims 1 and 3, which includes the cited sequence of starting and stoppage of supply of processing gas, power and voltage as cited.

Allowable Subject Matter
Claims 4-5 are allowed.

Response to Amendment
Applicant’s arguments, see page 7, filed April 30, 2025, with respect to the objection to the drawings and the 35 USC 102 rejection have been fully considered and are persuasive. The objection and rejection under 35 USC 102 have been withdrawn.
Claims 1, 3, 6-9 and 13-17 are now rejected under 35 U.S.C. 103 as being unpatentable over Jun et al (US 2012/0006351 A1) in view of Murakami et al (US 2012/0241412 A1). Reliance upon Kashimura (US 11,456,199 B2) is withdrawn. Claims 4-5 are allowed.

Response to Arguments
Applicant's arguments filed April 30, 2025, have been fully considered but they are not persuasive, to the extent they still apply.
Applicant’s most persuasive argument is that “Murakami merely describes that a DC voltage is applied to the upper electrode after applying high-frequency power for plasma generation.” However, the rejection already acknowledges that Murakami applies DC voltage to the upper electrode. Murakami is not relied upon to teach applying DC voltage to the ESC because the primary reference already teaches that feature. Murakami does, however, teach the order of first applying plasma power and then applying a secondary DC voltage to an electrode. That secondary electrode can be an upper electrode, but it can also be the ESC. Jun, as shown in Figure 5, supplies voltage 160 to upper electrode [0079], or as shown in Figures 3-4, supplies voltage 121a,b to the ESC. A skilled artisan would look to the teachings of Murakami and fairly learn that the voltage can be applied to the ESC in the order cited, as opposed to being applied to the upper electrode.
Applicant argues that Murakami does not disclose or suggest stopping application of voltage to the ESC before stopping supply of power for generating plasma. Absent criticality, this order is obvious. The primary reference already necessarily stops application of the voltage to the ESC and stops supply of power for generating plasma. The cited order is logical, but also within the grasp of a skilled artisan in order to achieve the desired cleaning results because Jun teaches that the voltage applied to the ESC has an effect on either cleaning the ESC or cleaning the interior of the chamber.
On page 9, applicant argues that the alleged combination of reference do not recognize the problems addressed by the claims. However, applicant has failed to explain what these problems are and how the solution is different.
Applicant argues that the references are unrelated. This is not persuasive because applicant has failed to explain why applicant believes they are unrelate.
Applicant argues that the configuration defined in the claims is much more precise than the generic functional difference articulated in the rejection. This argument is not understood because the rejection mirrors the claim language. Please explain this argument further.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
In response to applicant’s argument that there is no teaching, suggestion, or motivation to combine the references, the examiner recognizes that obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, the person of ordinary skill in the art would grasp the order of starting and stopping gas supply, plasma power and ESC voltage. The art of plasma processing requires a high level of skill, and starting and stopping the supplies as cited are within the scope of the skilled artisan.
Applicant's arguments regarding claims 3, 9, 13-17 fail to comply with 37 CFR 1.111(b) because they amount to a general allegation that the claims define a patentable invention without specifically pointing out how the language of the claims patentably distinguishes them from the references.

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 ANITA K ALANKO whose telephone number is (571)270-0297. The examiner can normally be reached Monday-Friday, 9 am-5pm.
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/ANITA K ALANKO/ Patent Examiner, Art Unit 1713