DETAILED ACTION
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 § 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. 2021/0366711 by Zi in view of U.S. 2020/0152486 by Kim in view of U.S. 2023/0408926 by Ruzic in view of WO 2018/031896 by Waller.
With regard to claims 1, 2, and 5-7, Zi teaches that a method for patterning a substrate using metal-comprising photoresist, wherein a layer of the metal-comprising photoresist is deposited on the substrate, UV radiation is emitted to photoresist layer through a mask so that the photoresist is selectively exposed to the UV light, and wherein the selectively-exposed photoresist is then “developed” by using a liquid developer (which is a liquid that is not deionized water, see Par. 0042-0059) to wash away portions of the photoresist, leaving an intended pattern of photoresist remaining on the substrate (Par. 0023, 0024, 0031, 0033-0035, 0040, 0042, 0100-0102). After the photoresist is “developed”, the remaining developer liquid is removed to dry the substrate, and Zi teaches that “any suitable removal technique may be used” to remove the remaining development liquid and dry the substrate (Par. 0059). The intended photoresist patten is then used as a mask for transferring the pattern to the underlying substrate (Par. 0063 and 0102). After the intended photoresist pattern is used to transfer the pattern to the underlying substrate, the used photoresist is then removed from the substrate by plasma ashing (Par. 0064 and 0102).
As discussed, after Zi’s photoresist is “developed”, the remaining developer liquid is removed to dry the substrate, and Zi teaches that “any suitable removal technique may be used” to remove the remaining development liquid and dry the substrate (Par. 0059). Zi does not teach used supercritical fluid to dry the substrate.
Kim teaches that when attempting to remove remaining developer liquid from a substrate with a photoresist pattern thereon and dry the substrate, such removal and drying can be successfully accomplished by rinsing the developed substrate with deionized water and subsequently supplying supercritical drying fluid onto the substrate to remove the deionized water and dry the substrate (Abstract; Par. 0035, 0036, 0042, 0045, and 0049-0054). Kim teaches that an advantage of using such supercritical drying is that the low surface tension of supercritical fluid advantageously prevents the photoresist pattern from undesirably collapsing or leaning (Par. 0036).
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 method of Zi using Kim’s step of performing a deionized water rinse and subsequently supplying supercritical drying fluid onto the substrate to remove the deionized water and dry the substrate, wherein this combination of water rinsing and supercritical drying serves to rinse away remaining development liquid and dry the substrate. As discussed, Zi teaches that “any suitable removal technique may be used” to remove the remaining development liquid and dry the substrate (Par. 0059 of Zi). Motivation for performing the modification was provided by Kim, who teaches that when attempting to remove remaining developer liquid from a substrate with a photoresist pattern thereon and dry the substrate, such removal and drying can be successfully accomplished by rinsing the developed substrate with deionized water and subsequently supplying supercritical drying fluid onto the substrate to remove the deionized water and dry the substrate, and Kim teaches that an advantage of using such supercritical drying is that the low surface tension of supercritical fluid advantageously prevents the photoresist pattern from undesirably collapsing or leaning. In this combination of Zi in view of Kim, the step of supplying the liquid developer (which is a liquid that is not deionized water, see Par. 0042-0059 of Zi) to wash away portions of the photoresist and the step of subsequently suppling the deionized water to the substrate are steps that, viewed together, correspond to applicant’s wetting of the substrate.
As discussed, in the combination of Zi in view of Kim, after the photoresist pattern is used to transfer the pattern to the underlying substrate, the used photoresist is then removed from the substrate by plasma ashing (Par. 0064 and 0102 of Zi).
The combination of Zi in view of Kim does not teach performing cleaning of the substrate after the supercritical drying of the substrate.
Ruzic teaches that, in the art of processing substrates, after a photoresist layer is removed via ashing, photoresist residue remaining on the substrate can advantageously then be removed via cleaning the substrate with cleaning liquid (Par. 0002 and 0022-0030).
Waller teaches that when attempting to remove residue of a metal-comprising photoresist from a substrate after a patterning process, a cleaning liquid comprising PGMEA and acetic acid can successfully be used to clean away such undesired residue (Page 3, line 2-3; Page 4, lines 2-4; Page 6, line 3 to Page 7, line 5). Waller teaches that cleaning a substrate to removed metal-comprising-photoresist residue can comprise a technique of removing such residue from the edge of the substrate, and Waller’s technique comprises rotating the substrate while an upper nozzle and a lower nozzle (the upper and lower nozzles are shown in Figure 1) supply the cleaning solution to the upper edge and lower edge of the substrate to remove residue from the edge surfaces (Page 4, lines 2-4; Page 5, line 20 to Page 8, line 29).
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 method of Zi in view of Kim by performing a cleaning routine of liquid-cleaning the substrate after the ashing-removal of the metal-comprising photoresist in order to remove photoresist residue from the substrate, wherein the cleaning routine comprises an edge-cleaning step of using Waller’s edge-cleaning technique to remove residue of metal-comprising photoresist from the substrate’s edge portion, wherein the edge-cleaning step comprises using upper and lower nozzles to discharge Waller’s cleaning liquid (comprising PGMEA and acetic acid) onto the upper edge and lower edge of the substrate while the substrate rotates. Motivation for performing liquid-cleaning of the substrate after the ashing-removal of the photoresist was provided by Ruzic, who teaches that, in the art of processing substrates, after a photoresist layer is removed via ashing, photoresist residue remaining on the substrate can advantageously then be removed via cleaning the substrate with cleaning liquid. Motivation for having the post-ashing cleaning comprise edge cleaning with Waller’s cleaning solution was provided by Waller, who teaches that cleaning a substrate to remove metal-comprising-photoresist residue can comprise a technique of removing such residue from the edge of the substrate, and Waller’s technique comprises rotating the substrate while an upper nozzle and a lower nozzle (the upper and lower nozzles are shown in Figure 1) supply Waller’s cleaning solution to the upper edge and lower edge of the substrate to remove residue from the edge surfaces. In this combination of Zi in view of Kim in view of Ruzic in view of Waller, having the liquid-cleaning of the post-ashing substrate comprise edge cleaning allows undesired residues on edge portions of the substrate to be advantageously removed from the substrate.
With regard to claim 3, the combination of Zi in view of Kim in view of Ruzic in view of Waller teaches having the acetic acid concentration range of about 0.1 wt% to about 25 wt% of the edge-cleaning liquid (page 6, line 3 to page 7, line 5 of Waller), and this range is considered to render applicant’s claimed concentration range obvious in accordance with MPEP 2144.05 due to the overlap of ranges.
With regard to claim 4, the combination of Zi in view of Kim in view of Ruzic in view of Waller does not explicitly teach that the deionized water is a solution. However, since the combination of Zi in view of Kim in view of Ruzic in view of Waller does not indicate that the deionized water should be degassed before being used to rinse the substrate, and since it is well known that deionized water can comprise dissolved gas molecules therein and still be considered as deionized water, 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 method of Zi in view of Kim in view of Ruzic in view of Waller such that the deionized water is water with dissolved gas molecules therein. As discussed, the combination of Zi in view of Kim in view of Ruzic in view of Waller does not indicate that the deionized water should be degassed before being used to rinse the substrate, and motivation for performing the modification is that the deionized water with some dissolved gas molecules therein could successfully perform its role of rinsing away developer liquid. In this combination of Zi in view of Kim in view of Ruzic in view of Waller, since the deionized water comprises some dissolved gas molecules, it can be considered a solution.
The combination of Zi in view of Kim in view of Ruzic in view of Waller does not explicitly teach that the developer liquid is applied to the substrate in a chamber. However, in the art of semiconductor processing, it is well known to have a processing step performed inside a chamber, as cleanliness is important in semiconductor processing and a chamber can provide some level of protection of a substrate from outside environmental contaminants. Therefore, 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 method of Zi in view of Kim in view of Ruzic in view of Waller by having the supply of the liquid developer to the substrate occur inside a chamber that protects the substrate from environmental contaminants. This chamber can be considered a wet chamber because the chamber is used to supply liquid developer. Motivation for performing the modification was provided by the fact that, in the art of semiconductor processing, it is well known to have a processing step performed inside a chamber, as cleanliness is important in semiconductor processing and a chamber can provide some level of protection of a substrate from outside environmental contaminants.
With regard to claim 8, the combination of Zi in view of Kim in view of Ruzic in view of Waller, as developed thus far, does not teach pre-cleaning the substrate after the substrate is coated with the metal-comprising photoresist and prior to exposing the substrate with the UV radiation.
Waller teaches that after metal-comprising photoresist is coated onto a substrate and before the coated photoresist is exposed to radiation, the substrate can advantageously be pre-cleaned by having its edge cleaned with cleaning liquid in order to remove photoresist from the edge of the substrate, as photoresist at the edge could undesirably contaminate processing equipment (Page 3, line 2 to Page 4, line 5; Page 6, line 3 to Page 8, line 29).
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 method of Zi in view of Kim in view of Ruzic in view of Waller by performing a pre-cleaning step after the metal-comprising photoresist is coated on the substrate and before the photoresist is exposed to UV light, wherein the pre-cleaning step is an edge-cleaning step as taught by Waller, and wherein the edge-cleaning removes photoresist from the edge of the substrate using cleaning liquid. Motivation for performing the modification was provided by Waller, who teaches that such a pre-cleaning step can advantageously removed photoresist from an edge of a coated substrate, as photoresist at the edge could undesirably contaminate processing equipment.
Claims 9-10 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. 2022/0197159 by Kamei in view of in view of U.S. 2020/0152486 by Kim in view of U.S. 2018/0272386 by McAlpin.
With regard to claims 9 and 10, Kamei teaches a method of processing a substrate, wherein the method comprises coating a metal-comprising photoresist onto the substrate, exposing the photoresist to harden selected portions of the photoresist, “developing” the photoresist by supplying a mixture of PGMEA and acetic acid to the exposed photoresist layer in order to dissolve the unexposed portions of the photoresist, and rinsing away the “developing” liquid with a cleaning solution that comprises PGMEA, wherein the “developing” step occurs inside a wet chamber (item 110 in Figure 4) into which the substrate is disposed (Par. 0014 and 0038-0060). In this method of Kamei, the supplying of the “developing” liquid and the subsequent supplying of the PGMEA-comprising rinsing liquid can, together, be considered to comprise a wetting of the substrate. In the method of Kamei, after the PGMEA-comprising rinsing liquid is used to rinse away the “developing” liquid, the substrate is exposed to radiation (Par. 0062-0064), subsequently heated-treated in a thermal treatment apparatus (Par. 0065), and subsequently cleaned with a pattern-cleaning liquid (Par. 0066-0068). This cleaning with the pattern-cleaning liquid corresponds to applicant’s cleaning step. After the cleaning with the pattern-cleaning liquid, the substrate is rinsed with pure water and dried (Par. 0070).
Kamei does not teach drying the substrate with supercritical fluid after the PGMEA-comprising rinsing liquid is supplied to the substrate.
Kim teaches that when attempting to remove remaining liquid from a substrate with a photoresist pattern thereon and dry the substrate, such removal and drying can be successfully accomplished by supplying supercritical drying fluid onto the substrate in a drying chamber to remove the remaining liquid and dry the substrate (Abstract; Par. 0035, 0036, 0042, 0045, and 0049-0054). Kim teaches that an advantage of using such supercritical drying is that the low surface tension of supercritical fluid advantageously prevents the photoresist pattern from undesirably collapsing or leaning (Par. 0036).
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 method of Kamei using Kim’s step of supplying supercritical drying fluid onto the substrate in a drying chamber to remove the remaining PGMEA-comprising rinsing liquid and dry the substrate. In this combination of Kamei in view of Kim, the supercritical drying removes remaining PGMEA-comprising rinsing liquid prior to the following irradiation step (Par. 0064 of Kamei) and thermal-treatment step (Par. 0065 of Kamei). Motivation for performing the modification was provided by Kim, who teaches that when attempting to remove remaining liquid from a substrate with a photoresist pattern thereon and dry the substrate, such removal and drying can be successfully accomplished by supplying supercritical drying fluid onto the substrate to remove the remaining liquid and dry the substrate, and Kim teaches that an advantage of using such supercritical drying is that the low surface tension of supercritical fluid advantageously prevents the photoresist pattern from undesirably collapsing or leaning.
As discussed, in the combination of Kamei in view of Kim, after the cleaning with the pattern-cleaning liquid, the substrate is rinsed with pure water and dried (Par. 0070 of Kamei).
The combination of Kamei in view of Kim does not teach that this drying is performed via heat-treating the substrate.
McAlpin teaches that when attempting to dry a substrate after rinsing the substrate, drying can successfully be achieved by heating the substrate with a heating means such as a hotplate (Par. 0083 and 0084).
Kamei teaches that, when attempting to heat a substrate, heating of a substrate can successfully be achieved via a heating chamber (illustrated in Figure 6 of Kamei) comprising a heated stage 161 on which the substrate is placed for heating (Par. 0046 of Kamei).
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 method of Kamei in view of Kim by using a heating chamber of the type taught by Kamei in Kamei’s Figure 6 to perform the drying of the substrate discussed in paragraph 0070 of Kamei. Kamei teaches that, when attempting to heat a substrate, heating of a substrate can successfully be achieved via a heating chamber (illustrated in Figure 6 of Kamei) comprising a heated stage 161 on which the substrate is placed for heating. Motivation for performing the modification was provided by McAlpin, who teaches that when attempting to dry a substrate after rinsing the substrate, drying can successfully be achieved by heating the substrate with a heating means such as a hotplate.
With regard to claim 14, in the combination of Kamei in view of Kim in view of McAlpin, the supercritical drying is performed inside a drying chamber, and the drying of paragraph 0070 of Kamei is performed inside a heating chamber that reads on applicant’s bake chamber.
The combination of Kamei in view of Kim in view of McAlpin does not specify that a first transfer unit is used to transfer the substrate into the supercritical drying chamber or that a second transfer unit is used to transfer the substrate into the heating chamber used to perform the drying of paragraph 0070 of Kamei. However, Kamei teaches that a plurality of substrate transfer apparatuses can by present in a substrate processing environment to move substrates to where they need to be (Par. 0021 and 0028). 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 method of Kamei in view of Kim in view of McAlpin by having one substrate transfer apparatus arranged to transfer the substrate into the supercritical drying chamber and by having a second substrate transfer apparatus arranged to transfer the substrate into the heating chamber used to perform the drying of paragraph 0070 of Kamei. Kamei teaches that a plurality of substrate transfer apparatuses can by present in a substrate processing environment to move substrates to where they need to be, and the motivation for performing the modification would be to allow the substrate to be successfully transferred to where it needs to go.
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over U.S. 2022/0197159 by Kamei in view of in view of U.S. 2020/0152486 by Kim in view of U.S. 2018/0272386 by McAlpin as applied to claim 10 above, and further in view of WO2018/031896 by Waller.
With regard to claim 11, the combination of Kamei in view of Kim in view of McAlpin teaches that the “developing” liquid for dissolving unexposed metal-comprising photoresist comprises PGMEA and acetic acid (Par. 0055 of Kamei).
The combination of Kamei in view of Kim in view of McAlpin does not specify the wt% concentration of acetic acid in the “developing” liquid.
Waller teaches that, when using a mixture of PGMEA and acetic acid to remove metal-comprising photoresist from a substrate, the concentration of acetic acid can range from 0.1 wt% to about 25 wt% (Page 3, line 2 to Page 4, line 5; Page 6, line 3 to Page 7, line 5). Waller is thus considered to teach that, when using a mixture of PGMEA and acetic acid to remove metal-comprising photoresist from a substrate, the acetic acid concentration can be considered a result-effective variable because some concentrations are more preferred than others.
In accordance with MPEP 2144.05, 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 method of Kamei in view of Kim in view of McAlpin by optimizing the concentration of the acetic acid in the “developing” liquid mixture of PGMEA and acetic acid used to dissolve the unexposed photoresist, as Waller is considered to teach that, when using a mixture of PGMEA and acetic acid to remove metal-comprising photoresist from a substrate, the acetic acid concentration can be considered a result-effective variable because some concentrations are more preferred than others.
Claims 12 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over U.S. 2022/0197159 by Kamei in view of in view of U.S. 2020/0152486 by Kim in view of U.S. 2018/0272386 by McAlpin as applied to claim 9 above, and further in view of WO2018/031896 by Waller.
With regard to claims 12 and 13, as discussed, the combination of Kamei in view of Kim in view of McAlpin teaches performing cleaning (see Par. 0066-0068 of Kamei) of the substrate to remove residue after the substrate is heated-treated in a thermal treatment apparatus (Par. 0065 of Kamei).
The combination of Kamei in view of Kim in view of McAlpin does not teach that the cleaning (of Par. 0066-0068 of Kamei) is performed using a cleaning solution comprising PGMEA and acetic acid.
Waller teaches that when attempting to remove residue of a metal-comprising photoresist from a substrate after a patterning process, a cleaning liquid comprising PGMEA and acetic acid can successfully be used to clean away such undesired residue (Page 3, line 2-3; Page 4, lines 2-4; Page 6, line 3 to Page 7, line 5). Waller teaches that cleaning a substrate to removed metal-comprising-photoresist residue can comprise a technique of removing such residue from the edge of the substrate, and Waller’s technique comprises rotating the substrate while an upper nozzle and a lower nozzle (the upper and lower nozzles are shown in Figure 1) supply the cleaning solution to the upper edge and lower edge of the substrate to remove residue from the edge surfaces (Page 4, lines 2-4; Page 5, line 20 to Page 8, line 29).
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 method of Kamei in view of Kim in view of McAlpin such that the cleaning (of Par. 0066-0068 of Kamei) also comprises Waller’s edge-cleaning technique, wherein metal-comprising-photoresist residue is removed form the edge by having upper and lower edge nozzles discharge a cleaning liquid taught by Waller onto the top edge and bottom edge of the substrate while the substrate rotates, wherein the cleaning liquid comprises a mixture of PGMEA and acetic acid. Motivation for performing the modification was provided by Waller, who teaches that when attempting to remove residue of a metal-comprising photoresist from a substrate after a patterning process, a cleaning liquid comprising PGMEA and acetic acid can successfully be used to clean away such undesired residue; Waller teaches that cleaning a substrate to removed metal-comprising-photoresist residue can comprise a technique of removing such residue from the edge of the substrate, and Waller’s technique comprises rotating the substrate while an upper nozzle and a lower nozzle supply the cleaning solution to the upper edge and lower edge of the substrate to remove residue from the edge surfaces.
The combination of Kamei in view of Kim in view of McAlpin in view of Waller teaches having the acetic acid concentration range of about 0.1 wt% to about 25 wt% of the edge-cleaning liquid (page 6, line 3 to page 7, line 5 of Waller), and this range is considered to render applicant’s claimed concentration range obvious in accordance with MPEP 2144.05 due to the overlap of ranges.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to RYAN L COLEMAN whose telephone number is (571)270-7376. The examiner can normally be reached 9-5 Monday-Friday.
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/RLC/
Ryan L. Coleman
Patent Examiner, Art Unit 1714
/KAJ K OLSEN/Supervisory Patent Examiner, Art Unit 1714
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