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 § 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 1-2, 7-8, 11-13, 15-16, 19, and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Kofuji et al. (US 20210335625 A1).
As to claim 1, Kofuji discloses a method for etching an etch layer, the method comprising a plurality of cycles wherein each cycle [Abstract, claim 1], comprises:
exposing the etch layer to neutral radicals for a time between 10 ms and 600 ms, wherein the neutral radicals are absorbed into the etch layer to form a modified part of the etch layer [claim 1]; and
exposing the etch layer to bombardment ions for a time between 10 ms and 600 ms, wherein the bombardment ions remove the modified part of the etch layer [claim 1].
Kofuji fails to explicitly disclose the time parameters of the alternately repeated steps, other than that “the first step has a longer processing time than the second step”, and therefore fails to explicitly disclose the underlined portions above.
However, Kofuji teaches as to the exposing the etch layer to neutral radicals, that the step is complete when “substantially no neutral radicals are further adsorbed” [para. 0044]; and as to the exposing the etch layer to bombardment ions, that “the etching amount in this case is determined by the amount of the oxygen radicals 4 adsorbed by the surface of the PMMA 2, if the oxygen radicals 4 are adsorbed in a saturated manner by the surface of the PMMA 2, a certain amount of PMMA 2 is etched” [para. 0046].
The timing the steps is therefore dependent upon the flux of neutral radicals, in the first step, and ion flux, in the second step, each of which are readily optimized by one of ordinary skill the art to achieve the desired saturated adsorption in the first step and etch rate in the second step.
Furthermore, “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See MPEP § 2144.05, II.
As to claim 2, Kofuji discloses the method, as recited in claim 1, wherein the exposing the etch layer to bombardment ions provides a bias of greater than 700 eV [para. 0035, “ion irradiation energy can be controlled from several tens of electron volts to several kilo electron volts”; See MPEP §2144.05, I.].
As to claim 7, Kofuji discloses the method, as recited in claim 1, wherein the exposing the etch layer to bombarding ions comprises providing a bias in a range of 200 eV to 2000 eV [para. 0035, “ion irradiation energy can be controlled from several tens of electron volts to several kilo electron volts”; See MPEP §2144.05, I.].
As to claim 8, Kofuji discloses the method, as recited in claim 7, wherein the bias is a continuous wave bias [para. 0035, “ion irradiation energy can be controlled from several tens of electron volts to several kilo electron volts”; See MPEP §2144.05, I.].
As to claim 11, Kofuji discloses the method, as recited in claim 1, further comprising:
providing a first transition from a modification gas to a bombardment gas in less than 0.5 seconds [para. 0036-37; Here, the transition from the first step to the second step requires only that the solenoid coil 14 adjust the magnetic field, which more probably than not require only a few hundred milliseconds], wherein the modification gas transformed to provide the neutral radicals the bombardment gas is transformed into bombardment ions, and wherein the first transition is after the exposing the etch layer neutral radicals and before exposing the etch layer to bombardment ions [para. 0036-37; claim 1], and
providing a second transition from the bombardment gas the modification gas wherein the second transition is after the exposing the etch layer to the bombardment ions and before exposing the etch layer to neutral radicals [claim 1; para. 0036-37].
As to claim 12, Kofuji discloses the method, as recited in claim 1, wherein the neutral radicals are chloride atoms or oxygen atoms [claim 2].
As to claim 13, Kofuji discloses the method, as recited in claim 1, wherein the bombardment ions are ions of argon [claim 3, “the noble gas is argon gas”], helium, neon, krypton, and xenon [claim 1, “noble gas”].
As to claim 15, Kofuji discloses the etching system for etching an etch layer over a substrate, the etching system [Fig. 3], comprising:
a processing chamber 12 [Fig. 3];
a substrate support 20 for supporting a substrate 21 in the processing chamber 12 [Fig. 3];
an RF power source 23 for providing RF power to etch chamber [Fig. 3];
a neutral radical source 15 adapted to provide neutral radicals in the processing chamber [para. 0035];
a bombardment gas source 15 adapted to provide bombardment gas in the processing chamber [para. 0035];
a controller 26controllably connected to the RF power source, the neutral radical source, and the bombardment gas source [para. 0034], configured to:
a) expose the etch layer to neutral radicals for a time between 10 ms and 600 ms, wherein the neutral radicals are absorbed into the etch layer to form a modified part of the etch layer [claim 1]; and
b) expose the etch layer to bombardment ions for a time between 10 ms and 600 ms, wherein the bombardment ions remove the modified part of the etch layer [claim 1].
Kofuji fails to explicitly disclose the time parameters of the alternately repeated steps, other than that “the first step has a longer processing time than the second step”, and therefore fails to explicitly disclose the underlined portions above.
However, Kofuji teaches as to the exposing the etch layer to neutral radicals, that the step is complete when “substantially no neutral radicals are further adsorbed” [para. 0044]; and as to the exposing the etch layer to bombardment ions, that “the etching amount in this case is determined by the amount of the oxygen radicals 4 adsorbed by the surface of the PMMA 2, if the oxygen radicals 4 are adsorbed in a saturated manner by the surface of the PMMA 2, a certain amount of PMMA 2 is etched” [para. 0046].
The timing the steps is therefore dependent upon the flux of neutral radicals, in the first step, and ion flux, in the second step, each of which are readily optimized by one of ordinary skill the art to achieve the desired saturated adsorption in the first step and etch rate in the second step.
Furthermore, “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See MPEP § 2144.05, II.
As to claim 16, Kofuji discloses the etching system, as recited in claim 15,wherein the exposing the etch layer to bombardment ions provides a bias of greater than 700 eV [para. 0035, “ion irradiation energy can be controlled from several tens of electron volts to several kilo electron volts”; See MPEP §2144.05, I.].
As to claim 19, Kofuji discloses the etching system, as recited in claim 15,wherein the exposing the etch layer to bombarding ions comprises providing a bias in a range of 200 eV to 2000 eV [para. 0035, “ion irradiation energy can be controlled from several tens of electron volts to several kilo electron volts”; See MPEP §2144.05, I.].
As to claim 20, Kofuji discloses the etching system, as recited in claim 19,wherein the bias is a continuous wave bias [para. 0035].
As to claim 23, Kofuji discloses the etching system, as recited in claim 15, wherein the controller is further configured to:
provide a first transition from a modification gas to a bombardment gas in less than 0.5 seconds [para. 0036-37; Here, the transition from the first step to the second step requires only that the solenoid coil 14 adjust the magnetic field, which more probably than not require only a few hundred milliseconds], wherein the modification gas transformed to provide the neutral radicals the bombardment gas is transformed into bombardment ions, and wherein the first transition is after the exposing the etch layer to neutral radicals and before exposing the etch layer to bombardment ions [para. 0036-37; claim 1]; and
provide a second transition from the bombardment gas to the modification gas, wherein the second transition is after the exposing the etch layer to the bombardment ions and before exposing the etch layer to neutral radicals [claim 1; para. 0036-37].
Claims 1, 3-6, 8-10, 12-15, 17-18, 20-22, and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Yang et al. (US 20210005425 A1) in view of Voronin et al. (US 20210366723 A1).
As to claim 1, Yang discloses a method for etching an etch layer, the method comprising a plurality of cycles wherein each cycle [claim 1, para. 0032-35, Fig. 1], comprises:
exposing the etch layer to neutral radicals for a time between 10 ms and 600 ms, wherein the neutral radicals are absorbed into the etch layer to form a modified part of the etch layer [claim 1; para. 0055]; and
exposing the etch layer to bombardment ions for a time between 10 ms and 600 ms, wherein the bombardment ions remove the modified part of the etch layer [claim 1; para. 0055].
Yang fails to explicitly disclose the first step includes “exposing the etch layer to neutral radicals” (emphasis added).
However, Voronin teaches a process of achieving surface modification using reactive neutral species, in conjunction with a step of ion bombardment, is an effective means of atomic layer etching a substrate layer, and provides improved etch rate, throughput and cost-efficiency [Abstract, para. 0046-49; Fig. 4A].
Therefore, 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 atomic layer etching modification step, of Yang, to include the atomic layer etching modification step, of Voronin, in order to achieve an atomic layer etching process having improved etch rate, throughput and cost-efficiency [Abstract, para. 0046-49; Fig. 4A].
As to claim 3, modified Yang discloses the method, as recited in claim 1, wherein the neutral radicals have a flux of greater than 1017 neutral radicals /cm2s [para. 0055; See MPEP §2144.05, I.].
As to claim 4, modified Yang discloses the method, as recited in claim 1, wherein the bombardment ions have a flux of greater than 1017 ions /cm2s [para. 0055; See MPEP §2144.05, I.].
As to claim 5, modified Yang discloses the method, as recited in claim 1, wherein the exposing the etch layer to bombarding ions is for a time between 10 ms and 250 ms [para. 0055; See MPEP §2144.05, I.].
As to claim 6, modified Yang discloses the method of claim 1, wherein the exposing the etch layer to bombarding ions is for a time between 10 ms and 25 ms [para. 0055; See MPEP §2144.05, I.].
As to claim 8, modified Yang discloses the method, as recited in claim 7, wherein the bias is a continuous wave bias [Yang, para. 0055; Voronin, para. 0048, Fig. 4A].
As to claim 9, modified Yang discloses the method, as recited in claim 7, wherein the bias is a pulsed bias [Voronin, para. 0048, Fig. 4A].
As to claim 10, modified Yang discloses the method, as recited in claim 7, wherein the bias is ramped up in less than 100 ms [Voronin, para. 0048-49, Fig. 4A; See MPEP §2144.05, I.].
As to claim 12, modified Yang discloses the method, as recited in claim 1, wherein the neutral radicals are chloride atoms [Voronin, para. 0054] or oxygen atoms.
As to claim 13, modified Yang discloses the method, as recited in claim 1, wherein the bombardment ions are ions of argon, helium [Voronin, para. 0054], neon, krypton, and xenon.
As to claim 14, modified Yang discloses the method, as recited in claim 1, wherein the exposing the etch layer to bombardment ions comprises providing an RF power of more than 2000 W [Yang, para. 0055; Voronin, para. 0035; See MPEP §2144.05, I.].
As to claim 15, modified Yang discloses the etching system for etching an etch layer over a substrate, the etching system, comprising:
a processing chamber 205 [Voronin, para. 0030, Fig. 2];
a substrate support 215 for supporting a substrate 210 in the processing chamber [Voronin, para. 0030, Fig. 2];
an RF power source 230 for providing RF power to etch chamber [Voronin, para. 0030, Fig. 2];
a neutral radical source adapted to provide neutral radicals in the processing chamber [Voronin, para. 0036, Fig. 3];
a bombardment gas source adapted to provide bombardment gas in the processing chamber [Voronin, para. 0036, Fig. 3];
a controller 270 controllably connected to the RF power source, the neutral radical source, and the bombardment gas source [Voronin, para. 0031, Fig. 2], configured to:
see rejection of claim 1.
In particular, Yang fails to explicitly disclose the first step includes “exposing the etch layer to neutral radicals” (emphasis added).
However, Voronin teaches an apparatus and process of achieving surface modification using reactive neutral species, in conjunction with a step of ion bombardment, is an effective means of atomic layer etching a substrate layer, and provides improved etch rate, throughput and cost-efficiency [Abstract, para. 0046-49; Fig. 4A].
Therefore, 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 atomic layer etching modification step and apparatus thereof, of Yang, to include the atomic layer etching modification step and apparatus thereof, of Voronin, in order to achieve an atomic layer etching process having improved etch rate, throughput and cost-efficiency [Abstract, para. 0046-49; Fig. 4A].
As to claim 17, modified Yang discloses the etching system, recited in claim 15, wherein the neutral radicals have a flux of greater than 1017 neutral radicals /cm2s [para. 0055; See MPEP §2144.05, I.].
As to claim 18, modified Yang discloses the etching system, as recited in claim 15,wherein the bombardment ions have a flux of greater than 1017 ions /cm2s [para. 0055; See MPEP §2144.05, I.].
As to claim 20, modified Yang discloses the etching system, as recited in claim 19,wherein the bias is a continuous wave bias [Voronin, para. 0048, Fig. 4A].
As to claim 21, modified Yang discloses the etching system, as recited in claim 19,wherein the bias is a pulsed bias [Voronin, para. 0048, Fig. 4A].
As to claim 22 modified Yang discloses the etching system, as recited in claim 19,wherein the bias is ramped up in less than 100 ms [Voronin, para. 0049, Fig. 4B; See MPEP §2144.05, I.].
As to claim 24, modified Yang discloses the etching system, as recited in claim 15, wherein the exposing the etch layer to bombardment ions comprises providing an RF power of more than 2000 W [Voronin, para. 0035; See MPEP §2144.05, I.].
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 conventional atomic layer etching (ALE) processes and apparatus and/or ALE processes utilizing neutral radicals [Abstracts].
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/CHRISTOPHER REMAVEGE/Examiner, Art Unit 1713
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