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 § 102
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 the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claims 9-10 are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Choi et al. (US 20220172966 A1).
As to claim 9, Choi discloses a substrate processing apparatus [Abstract; para. 0003] comprising:
a phosphoric acid processing unit that has a processing tank and immerses a plurality of substrates in phosphoric acid inside said processing tank [para. 0076; Fig. 4];
a coarse rinse processing unit that replaces a part of said phosphoric acid adhering to said plurality of substrates with a rinse liquid to an extent that said phosphoric acid remains in patterns of said plurality of substrates [para. 0076; Fig. 4]; and
a single-substrate processing unit that dries said plurality of substrates one by one [Abstract; Fig. 14].
As to the “coarse rinse processing unit”, the Courts have held that if the prior art structure is capable of performing the intended use, then it meets the claim. See MPEP § 2114. Here, the instant invention achieves the effect of “said phosphoric acid remains in patterns of said plurality of substrates after said phosphoric acid processing step” by processing the wafers in the rinse liquid for a period of about 2 minutes to 5 minutes [Instant Specification, para. 0080]. The apparatus of Choi is configured to achieve a rinsing step of any desired duration [para. 0092-93], and therefore is capable of performing the intended use, and anticipates the limitation.
As to claim 10, Choi discloses the substrate processing apparatus according to claim 9, further comprising a form changing unit that changes forms of said plurality of substrates between a horizontal form and an upright form [Figs. 7-11], wherein said phosphoric acid processing unit immerses said plurality of substrates in the upright form in said phosphoric acid inside said processing tank [Fig. 4], and said single-substrate processing unit performs drying processing on each of the substrates in the horizontal form [Fig. 14].
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 1-7 are rejected under 35 U.S.C. 103 as being unpatentable over Microtech Systems (“Phosphoric Acid Nitride Removal”, Microtech Systems, Inc., Published 06/08/2007), herein “Microtech”, in view of Choi et al. (US 20220172966 A1).
As to claim 1, Microtech discloses substrate processing method [Fig. 1, Introduction] comprising:
a phosphoric acid processing step of immersing a plurality of substrates in phosphoric acid inside a processing tank [Typical Process and Performance Parameters; Hardware Considerations, “batch of wafer”];
a coarse rinse processing step of replacing a part of said phosphoric acid adhering to said plurality of substrates with a first rinse liquid to an extent that said phosphoric acid remains in patterns of said plurality of substrates after said phosphoric acid processing step [Post Etch Rinsing, “wafers are
transferred into a full bath of heated UPW (> 65°C), which is dumped after 15-30 sec”].
As to the coarse rinsing processing step, the instant invention achieves the effect of “said phosphoric acid remains in patterns of said plurality of substrates after said phosphoric acid processing step” by processing the wafers in the rinse liquid for a period of about 2 minutes to 5 minutes [Instant Specification, para. 0080].
Here, Microtech teaches a quick dump process comprising a 15-30 second immersion of the wafers in a water bath [Post Etch Rinsing, “wafers are transferred into a full bath of heated UPW (> 65°C), which is dumped after 15-30 sec”].
Therefore, given the similarity of the rinse process of the instant invention and that of Microtech, it is expected that the process of Microtech would remove the same or less phosphoric acid from between the patterned wafer [Introduction, “thermal oxides, LOCOS (local oxidation of silicon) or STI (shallow trench isolation”].
Microtech fails to explicitly disclose:
a single-substrate drying processing step of drying said plurality of substrates one by one after said coarse rinse processing step.
However, Choi et al. (US 20220172966 A1) teaches an apparatus for treating substrate [Abstract] for stripping SiN from substrates [para. 0003] comprises a first treating part performing, a liquid treatment, (including phosphoric acid for removing SiN [para. 0076]) on a plurality of substrates in a batch-type treating, method and a second treating part treating the substrates, including pure water [para. 0076]) which have been treated at the first treating part, and performing, the liquid treatment or a drying treatment on a single substrate a single-type treating method [Abstract].
Choi therefore teaches:
a single-substrate drying processing step of drying said plurality of substrates one by one after said coarse rinse processing step [Abstract].
It would have been prima facie obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the process of treating a wafer in a tank of phosphoric acid and a rinsing tank of water, of Microtech, to include the substrate treatment apparatus and method for treating batches of wafers in a tank of phosphoric acid and a rinsing tank of water, and then drying the wafers in a single-type drying step, of Choi, because it is an effective method of stripping silicon nitride from a batch of wafers, as taught by Choi [Abstract; para. 0003].
As to claim 2, modified Microtech discloses the substrate processing method according to claim 1, wherein said coarse rinse processing step ends in a state where a concentration of said phosphoric acid in said patterns is 50% or more [Post Etch Rinsing, “wafers are transferred into a full bath of heated UPW (> 65°C), which is dumped after 15-30 sec”].
Here, Microtech teaches a quick dump process comprising a 15-30 second immersion of the wafers in a water bath [Post Etch Rinsing, “wafers are transferred into a full bath of heated UPW (> 65°C), which is dumped after 15-30 sec”].
Therefore, given the similarity of the rinse process of the instant invention and that of Microtech, it is expected that the process of Microtech would remove the same or less phosphoric acid from between the patterned wafer [Introduction, “thermal oxides, LOCOS (local oxidation of silicon) or STI (shallow trench isolation”].
As to claim 3, modified Microtech discloses the substrate processing method according to claim 1, wherein said coarse rinse processing step includes a temperature reduction step of reducing a temperature of said first rinse liquid [Post Etch Rinsing, “sequence is repeated 3 to 4 times with hot water being used in the first step and cold water in the last ones.”].
As to claim 4, modified Microtech discloses the substrate processing method according to claim 1, the method further comprising a coarse drying processing step of removing at least a part of a liquid adhering to out-of-pattern regions of said plurality of substrates without said patterns formed thereon between said coarse rinse processing step and said single-substrate drying processing step [Post Etch Rinsing, “The wafers are transferred into a full bath of heated UPW (> 65°C), which is dumped after 15-30 sec.”].
As to claim 5, modified Microtech discloses the substrate processing method according to claim 4, wherein in said coarse drying processing step, said plurality of substrates are exposed to an atmosphere of steam of a second rinse liquid having latent heat of vaporization lower than that of said first rinse liquid [Post Etch Rinsing, “After drain the tank is refilled from the bottom with or without top spray rinse followed by a 60-120 sec overflow.”].
Here, the filling of the tank with water would inherently produce water vapor (i.e., steam) to which the plurality of substrates are exposed, and further the refilled water would have a lower latent heat of vaporization than the drained water by virtue of the higher concentration of phosphoric acid in the drained water.
As to claim 6, modified Microtech discloses a substrate processing method according to claim 1,wherein said phosphoric acid processing step includes:
a step of lowering said plurality of substrates to immerse said plurality of substrates in said phosphoric acid inside said processing tank [Microtech, Post Etch Rinsing, “wet immersion processing the wafers”; Choi, para. 0076-77]; and
a step of raising said plurality of substrates at a first rising speed to pull up said plurality of substrates from said processing tank [Microtech, Post Etch Rinsing, “wet immersion processing the wafers”; Choi, para. 0076-77], and
said coarse rinse processing step includes:
a step of lowering said plurality of substrates to immerse said plurality of substrates in said first rinse liquid [Microtech, Post Etch Rinsing, “quick dump process”; Choi, para. 0076-77] and
a step of raising said plurality of substrates at a second rising speed lower than or equal to said first rising speed to pull up said plurality of substrates from said first rinse liquid [Choi, para. 0076-77].
Here, Choi teaches the rinsing process may comprise moving the carrier containing a plurality of substrates from the phosphoric acid tank to rinsing tanks containing water [para. 0076-77, Fig. 4], and therefore renders obvious modifying the drain and fill method of rinsing the wafers in a single tank, of Microtech, to include the method rinsing the wafers in a series of water tanks, of Choi, in order to achieve cleaning of the treated substrates, as taught by Choi [Abstract; para. 0076].
Choi fails to explicitly teach the rate of lowering and raising the carrier in the phosphoric acid and cleaning tank, however absent any teaching to the contrary, one of ordinary skill in the art would infer a substantially similar raising and lower rate for each step.
As to claim 7, modified Microtech discloses the substrate processing method according to claim 1, the method further comprising:
a first step of transferring said plurality of substrates to a first carrier after said coarse rinse processing step [para. 0145, “when the first transfer unit 132 has a batch-hand, a storage container C may be disposed in each of the batch-type liquid treating chambers 140”];
a second step of transferring said first carrier to a load port of a single-substrate type processing apparatus after said first step [Figs. 8-9];
a third step of transferring said plurality of substrates one by one from said first carrier of said load port to a single-substrate processing unit between said second step and said single-substrate drying processing step [Fig. 11]; and
a fourth step of transferring the substrates from said single-substrate processing unit to a second carrier of said load port after said single-substrate drying processing step. [para. 0090].
Allowable Subject Matter
Claim 8 is 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.
As to claim 8, the prior art of record fails to teach the combination of the substrate processing method according to claim 7, with the feature of “wherein said first carrier includes a water-absorbing member that is partially in contact with an out-of-pattern region of each of said plurality of substrates without said pattern formed thereon.”, of claim 8.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure: The additionally cited references are cited to show methods and apparatus for sequentially treating semiconductor substrates in phosphoric acid and in a rinsing liquid and/or thereafter drying the wafers [Abstracts].
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/CHRISTOPHER REMAVEGE/Examiner, Art Unit 1713