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 .
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 11-12 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the enablement requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to enable one skilled in the art to which it pertains, or with which it is most nearly connected, to make and/or use the invention.
Regarding claim 11, the specification discloses frequencies in the Hz range which is inconsistent with the claim frequencies of kHz. It was known in the art that that plasma processing can occur using the Hz to MHz range. Plasma processing using frequency ranges with a magnitude difference between the claims and specification could result in potentially the same structure but would require additional experimentation to determine the parameters such as etch rate and deposition rate in the different frequency range.
Claim 12 is rejected as it is dependent on claim 11.
Regarding claim 12, similar to claim 11, the specification discloses frequencies in the Hz range which is inconsistent with the claim frequencies of kHz. It was known in the art that that plasma processing can occur using the Hz to MHz range. Plasma processing using frequency ranges with a magnitude difference between the claims and specification could result in potentially the same structure but would require additional experimentation to determine the parameters such as etch rate and deposition rate in the different frequency range.
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.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-12 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding claim 1, [0070] discloses that the first step is represented in Fig 10. This shows a mask on the substrate prior to etching. [0067] discloses the mask is patterned on the substrate. The limitation of the first step comprises etching silicon by plasma. This limitation does not mention a mask. As such, the limitation can be read as the silicon substrate is etched with no mask. For purposes of Examination, Examiner will add an initialization step consisting of applying a mask on a silicon substrate prior to the first step.
Further, the limitation of “a third step of etching the silicon such that an etching shape becomes perpendicular” is confusing. The silicon of the third step can be associated with either the silicon that was etched in the first step (the substrate that is being used to form trenches in) or the silicon that was deposited on the mask in the second step. The perpendicular etch shape can apply to either source of silicon in this case. For the silicon substrate, “perpendicular” can mean the shape is perpendicular to the substrate. For the silicon on the mask, “perpendicular” can mean that the shape is formed to be perpendicular to the mask the silicon was deposited upon, that is the silicon on the mask is not tapered.
Claims 2-12 would also be rejected as they are dependent on claim 1.
Regarding claim 6, the claim recites the limitation “the first pulse” in line 2. There is insufficient antecedent basis for this limitation in the claim. For purposes of Examination, Examiner will treat this limitation to mean “a first pulse.”
Further, the claim recites the limitation “the second pulse” in line 2. There is insufficient antecedent basis for this limitation in the claim. For purposes of Examination, Examiner will treat this limitation to mean “a second pulse.”
Claims 7-12 would also be rejected as they are dependent on claim 6.
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 1-4 are rejected under 35 U.S.C. 103 as being unpatentable over Nozawa et. al. (US 20120064726 A1), hereinafter Nozawa, in view of Ventzek et. al. (US 20220310357 A1), hereinafter Ventzek.
Regarding claim 1, Nozawa teaches a plasma processing method for forming shallow trench isolation (Fig 8, [0073]), the method comprising: a first step of etching silicon by plasma (Fig 8C, [0073]); a second step of depositing a deposited film (Fig 8D, [0080], when the bias is in an OFF state a protective film is produced) containing a silicon element on a mask (Fig 11 protective film 59, [0094]; film has silicon); a third step of etching the silicon by plasma (Fig 8C, [0073]) such that an etching shape becomes perpendicular (Fig 11 the shape is perpendicular); and a fourth step of depositing a deposited film (Fig 8D, [0080], when the bias is in an OFF state a protective film is produced), wherein the first step (Fig 8C, [0073]) to the fourth step (Fig 8D, [0073]) are repeated a predetermined number of times (etching is stopped when the bottom reaches a certain depth, [0075]), the third step (Fig 8C, [0073]) is performed while radio frequency power (Fig 9 line 62, [0076]) modulated by a second pulse (Fig 9 line 61, [0076]) is supplied to a sample (Fig 1 supporting table 14, [0060]) having the silicon (target is silicon, [0067]) as a substrate (Fig 1 target substrate W, [0060]).
Nozawa fails to teach a fourth step of depositing a deposited film containing SiO on the mask, the plasma in the third step is generated by radio frequency power modulated by a first pulse, and a frequency of the first pulse in the third step is higher than a frequency of the second pulse in the third step.
However, Nozawa teaches the reaction by-products depend on the process gas used ([0067]). These byproducts are then used to form the protective film ([0080]). It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention that using process gases that contain O2 would result in a deposited film containing SiO. Nozawa teaches using process gases containing Ar, HBr, and O2 ([0073]). This results in a protective film primarily made of SiBrO ([0094]).
However, Ventzek teaches the plasma (Fig 10 plasma 42, [0102] corresponds to Nozawa: Fig 1 not shown in plasma chamber) in the third step is generated by radio frequency power (Fig 10 source power supply 35, [0099]) modulated by a first pulse (Fig 1 source power pulse, [0034]), and a frequency (Fig 1 source power frequency fS, [0034]) of the first pulse (Fig 1 source power pulse 12, [0034]) in the third step is higher (bias power frequency fB is lower than source power frequency fS, [0034]) than a frequency (Fig 1 bias power frequency fB, [0034]) of the second pulse (Fig 1 bias power pulse 14, [0034] corresponds of Nozawa: Fig 9 line 61, [0076]) in the third step.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Nozawa to incorporate the teachings of Ventzek by having a plasma that has a source pulse and to have the source pulse frequency being higher than the bias pulse frequency. This would improve feature profiles ([0027]).
Regarding claim 2, Nozawa as modified in claim 1 fails to teach an OFF time of the first pulse in the third step is shorter than a time until afterglow discharge disappears.
However, Ventzek teaches an OFF time of the first pulse in the third step is shorter than a time until afterglow discharge disappears.
Ventzek teaches an afterglow phase portion (Fig 1 afterglow phase 18, [0038]) of the plasma cycle (Fig 1 cycle 16, [0036]). Ventzek further teaches the plasma (Fig 1 electronegative plasma 42, [0038]) in the afterglow portion has not approached zero (Fig 1 102 qualitative graph 102, [0037]) before the cycle repeats.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Nozawa to incorporate the teachings of Ventzek by having an OFF time of the first pulse in the third step being shorter than a time until afterglow discharge disappears. This would improve the conditions for charge exchange collisions in the plasma remaining ([0043]).
Regarding claim 3, Nozawa as modified in claim 2 fails to teach an OFF time of the second pulse in the third step is longer than a time during which charges accumulated in the sample are removed.
However, Ventzek teaches charge buildup on the sample can cause uneven etching ([0091]). One having ordinary skill in the art before the effective filing date of the claimed invention would recognize the need to allow time for accumulated charges to be removed to prevent uneven etching. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to allow time for charges accumulated to be removed and in doing so an OFF time of the second pulse in the third step should be longer than a time during which charges accumulated in the sample are removed. MPEP 2143(I)(G)
Regarding claim 4, Nozawa as modified in claim 3 fails to teach a duty ratio of the first pulse in the third step is larger than a duty ratio of the second pulse in the third step.
However, Ventzek teaches the source power pulses and bias power pulses can be modified to affect the plasma temperature ([0036] and Fig 1 schematic timing diagram 100, [0034]). The duty ratio comparison is therefore a result-effective variable.
It would have been obvious to one of ordinary skill in the art before the effective filing date of
the claimed invention to vary, through routine optimization, the duty ratio of both the first pulse and second pulse as Ventzek has identified the duty ratios as a result-effective variable. Further, one of ordinary skill in the art would have had a reasonable expectation of success to arrive at a duty ratio of the first pulse in the third step being larger than a duty ratio of the second pulse in the third step, in order to achieve the desired balance between plasma temperature and plasma flux, as taught by Ventzek. MPEP 2144.05.
Furthermore, the applicant has not presented persuasive evidence that the claimed difference is for a particular purpose that is critical to the overall claimed invention (i.e., that the invention would not work without the specific claimed differences).
Claims 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Nozawa et. al. (US 20120064726 A1), hereinafter Nozawa, in view of Ventzek et. al. (US 20220310357 A1), hereinafter Ventzek, in further view of Matsui et. al. (US 20200335354 A1), hereinafter Matsui.
Regarding claim 5, Nozawa as modified in claim 4 fails to teach the deposited film containing the silicon element is deposited by plasma generated using a SiCl4 gas.
However, Matsui teaches the composition ([0074]) of a protective film (Fig 6 protective film 20, [0072]) is determined by the precursor gases which can include SiCl4 ([0074]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified Nozawa and Ventzek to incorporate the teachings of Matsui by using SiCl4 gas to generate the desired deposited film. This would allow for choosing the composition of the deposited film ([0074]).
Examiner notes that Nozawa teaches the protective film when made of reaction byproducts is thin ([0080]) and the sides of the protection film can be etched (Fig 11). This would provide motivation for making a thicker film for one having ordinary skill in the art before the effective filing date of the claimed invention.
Regarding claim 6, Nozawa as modified in claim 5 fails to teach a duty ratio of the first pulse in the first step is larger than a duty ratio of the second pulse in the first step.
However, Ventzek teaches the source power pulses and bias power pulses can be modified to affect the plasma temperature ([0036] and Fig 1 schematic timing diagram 100, [0034]). The duty ratio comparison is therefore a result-effective variable.
It would have been obvious to one of ordinary skill in the art before the effective filing date of
the claimed invention to vary, through routine optimization, the duty ratio of both the first pulse and second pulse as Ventzek has identified the duty ratios as a result-effective variable. Further, one of ordinary skill in the art would have had a reasonable expectation of success to arrive at a duty ratio of the first pulse in the first step being larger than a duty ratio of the second pulse in the first step, in order to achieve the desired balance between plasma temperature and plasma flux, as taught by Ventzek. MPEP 2144.05.
Furthermore, the applicant has not presented persuasive evidence that the claimed difference is for a particular purpose that is critical to the overall claimed invention (i.e., that the invention would not work without the specific claimed differences).
Allowable Subject Matter
Claims 7-12 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Regarding claim 7, the closest art is Nozawa et. al. (US 20120064726 A1), hereinafter Nozawa, in view of Ventzek et. al. (US 20220310357 A1), hereinafter Ventzek, in further view of Matsui et. al. (US 20200335354 A1), hereinafter Matsui.
Nozawa as modified in claim 6 teaches the second pulse (Fig 9 line 61, [0076]) in the third step (Fig 8C, [0073]) and the second pulse (Fig 9 line 61, [0076]) in the first step (Fig 8C, [0073]).
Nozawa as modified in claim 6 fails to teach the frequency of the second pulse in the third step is lower than a frequency of the second pulse in the first step.
Claims 8-12 would be allowable because they are dependent on claim 7.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ALVIN L LEE whose telephone number is (703)756-1921. The examiner can normally be reached Monday - Friday 8:30 am - 5 pm (ET).
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, STEVEN GAUTHIER can be reached at (571)270-0373. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/ALVIN L LEE/Examiner, Art Unit 2813
/STEVEN B GAUTHIER/Supervisory Patent Examiner, Art Unit 2813