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 .
Status of the Claims
Claims 1-8 are pending and rejected. Claims 9 and 10 are withdrawn.
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-8 in the reply filed on 11/14/2025 is acknowledged. Claims 9 and 10 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 11/14/2025.
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.
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 1-3 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Ito, US 2020/0312654 A1 in view of Kelman, US 2016/0225608 A1 (both references provided on the PTO-892 of 9/16/2025).
Regarding claim 1, Ito teaches a method of forming a nitride film (abstract), comprising:
(a) preparing a substrate (loading the substrate into the processing apparatus, 0059-0060 and 0070);
(b) supplying a halogen-containing raw material gas into a processing container (supplying a raw material gas such as DCS into a processing container, 0071, Fig. 7, and Fig. 8);
(c) supplying a nitrogen-containing gas into the processing container (supplying a nitriding gas into the processing container, 0073, Fig. 7, and Fig. 8, where the nitriding gas is ammonia gas or nitrogen gas, 0044),
wherein the nitride film is formed by repeating a cycle including (b) and (c) a set number of times (where the process steps are defined as one cycle and they are repeated by a plurality of cycles until a predetermined thickness is obtained to form the nitride film, 0074, Fig. 7, and Fig. 8); and
(d) reforming the nitride film by supplying a hydrogen-containing gas to the processing container to generate a hydrogen radical, between (b) and (c) (supplying a plasma-converted hydrogen gas to the processing container, 0072, Fig. 7, and Fig.8, where since the gas is plasma-converted it is understood to include hydrogen radicals and because they indicate that converting hydrogen gas to plasma results in hydrogen radicals, 0053, where the hydrogen gas supply step modifies the Si-containing layer to remove halogen, 0042, so as to reform the film).
They do not teach providing the hydrogen radicals by DC pulse voltage. Ito teaches applying a high-frequency voltage between electrodes to convert the hydrogen gas to plasma (0053).
Kelman teaches dry-etching a semiconductor substrate with a fluorine containing species and exposing the dry-etched substrate to hydrogen atoms, prior to epitaxially depositing a semiconductor layer to the surface of the substrate (abstract). They teach that the hydrogen atoms may be produced by decomposing H2 by exposing H2 to plasma (0024). They teach that the hydrogen can be decomposed by exposing to a pulsed DC plasma (0024 and 0056). They teach that the grounded electrode assembly is made from materials compatible with hydrogen and fluorine process chemistry used when the substrate is dry etched with a fluorine containing species and expose to hydrogen atoms (radicals) (0047), indicating that the process will include the formation of hydrogen radicals since the assembly is formed from materials that are compatible with hydrogen radicals. They teach that the exposure to hydrogen atoms results in removing fluorine termination from a bulk silicon film (0015).
From the teachings of Kelman, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Ito to have generated the hydrogen plasma using a pulsed DC voltage because Kelman teaches that a pulsed DC plasma generates a hydrogen plasma which will include radicals such that it will be expected to generate the hydrogen plasma as desired and because they indicate that the process removes a halogen (fluorine) from a silicone film such that it will also be expected to remove the halogen as in the process of Ito. Therefore, the hydrogen plasma (including radicals) will be generated by a DC pulse voltage between (b) and (c).
Regarding claim 2, Ito in view of Kelman suggest the process of claim 1. While they do not teach that the stress of the nitride film formed by the claimed process is a tensile stress, since they suggest the claimed process, the resulting film is also expected to have a tensile stress. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 3, Ito in view of Kelman suggest the process of claim 1. Ito further teaches that when forming the nitride film, the substrate is a ta temperature ranging from 400°C to 650°C and the pressure is in a range of from 13 Pa to 1333 Pa (0061 and 0070).
Kelman further teaches that during the exposure of the substrate to hydrogen atoms, the temperature of the substrate may be at least below 650°C, where the time of the exposure of the substrate to the hydrogen atoms may depend on the temperature, pressure, plasma power, and frequency (0031). They teach that the power of the plasma discharge during the atomic hydrogen exposure may range from 10 W to 2000 W or form 20 W to 1000 W or from 40 W to 500 W or from 60 W to 200 W (0026).
From this, the process will have a pressure and a power during step (d) such that the selected pressure and power parameter is considered to provide controlling the stress of the film.
Regarding claim 8, Ito in view of Kelman suggest the process of claim 1. As discussed above for claim 1, Ito teaches that the process steps are defined as one cycle and they are repeated by a plurality of cycles until a predetermined thickness is obtained to form the nitride film (0074, Fig. 7, and Fig. 8). Therefore, steps (b), (d), and (c) will be repeated in this order a set number of times.
Claims 1-3 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Tonegawa, US 2018/0342385 A1 in view of Kelman, US 2016/0225608 A1.
Regarding claim 1, Tonegawa teaches a method of forming a nitride film (abstract), comprising:
(a) preparing a substrate (loading a wafer boat on which wafers are mounted into the processing vessel, 0050);
(b) supplying a halogen-containing raw material gas into a processing container (supplying DCS into the processing vessel, 0053 and Fig. 3);
(c) supplying a nitrogen-containing gas into the processing container (supplying ammonia gas into the processing vessel, 0055, Fig. 3, and Fig. 8B),
wherein the nitride film is formed by repeating a cycle including (b) and (c) a set number of times (where the process steps are repeated a predetermined number of times to form and ALD-SiN film having a predetermined thickness, 0051 and Fig. 3); and
(d) reforming the nitride film by supplying a hydrogen-containing gas to the processing container to generate a hydrogen radical, between (b) and (c) (performing a hydrogen radical purge step where an H2 gas is supplied into the process vessel and radicals are generated by plasmarizing the H2 gas, 0054, Fig. 3, and Fig. 8B).
They teach that in the hydrogen radical purge, impurity Cl or H and the excessive Si are removed as HCl, SiH4, or the like (0065).
They do not teach providing the hydrogen radicals by DC pulse voltage.
Kelman teaches dry-etching a semiconductor substrate with a fluorine containing species and exposing the dry-etched substrate to hydrogen atoms, prior to epitaxially depositing a semiconductor layer to the surface of the substrate (abstract). They teach that the hydrogen atoms may be produced by decomposing H2 by exposing H2 to plasma (0024). They teach that the hydrogen can be decomposed by exposing to a pulsed DC plasma (0024 and 0056). They teach that the grounded electrode assembly is made from materials compatible with hydrogen and fluorine process chemistry used when the substrate is dry etched with a fluorine containing species and expose to hydrogen atoms (radicals) (0047), indicating that the process will include the formation of hydrogen radicals since the assembly is formed from materials that are compatible with hydrogen radicals. They teach that after dry-etching with the fluorine-containing species, the surface of the semiconductor may become fluorine terminated (0003 and 0015). They teach that upon exposure to the hydrogen atoms, the exposed surface of the bulk semiconductor may be hydrogen terminated so as to provide Si-H groups, making the surface amenable for epitaxial deposition (0015).
From the teachings of Kelman, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Tonegawa to have generated the hydrogen plasma using a pulsed DC voltage because Kelman teaches that a pulsed DC plasma generates a hydrogen plasma which will include radicals for the removal of a halogen from a surface such that it will be expected to generate the hydrogen plasma as desired for removal of chlorine from the surface. Therefore, the hydrogen plasma (including radicals) will be generated by a DC pulse voltage between (b) and (c).
Regarding claim 2, Tonegawa in view of Kelman suggest the process of claim 1. Tonegawa teaches that the process is done to reduce the tensile stress in the film (0012). They teach that the process reduces the tensile stress, however, the films still have a tensile stress (0074-0075 and Fig. 10). Therefore, the film in the process of Tonegawa in view of Kelman is also expected to have a tensile stress due to the teachings of Tonegawa and because Tonegawa in view of Kelman suggest performing the process of claim 1. According to MPEP 2112.01 I, “Where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977)”.
Regarding claim 3, Tonegawa in view of Kelman suggest the process of claim 1. Tonegawa teaches performing the hydrogen purge using a H2 gas ratio of 50% and a high frequency power of 100W (0072) and then increasing the H2 gas ratio to 80% and the power to 200 W, where increasing the H2 gas ratio and the power, the tensile stress is lower (0075). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have controlled the tensile stress in the film by controlling the power of the DC pulse voltage because Tonegawa indicates that increasing the power used to generate the plasma can decrease stress in the film.
Additionally, since the process will have a pressure and a power during step (d), the selected pressure and power parameter is considered to provide controlling the stress of the film.
Regarding claim 8, Tonegawa in view of Kelman suggest the process of claim 1. As discussed above for claim 1, Tonegawa teaches that the steps are repeated a predetermined number of times to form an ALD-SiN film having a predetermined thickness (0051 and Fig. 3). Therefore, steps (b), (d), and (c) will be repeated in this order a set number of times.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Ito or Tonegawa in view of Kelman as applied to claim 1 above, and further in view of Iwashita, US 2019/0385815 A1.
Regarding claim 4, Ito or Tonegawa in view of Kelman suggest the process of claim 1.
Ito teaches using a high frequency power source such as an RF power source for plasma nitriding (0052, 0064, and Fig. 8). Ito further teaches generating plasma between a pair of electrodes using RF power to convert the hydrogen gas to plasma and for providing the nitrogen plasma (0052-0053, 0055, and Fig. 2).
Tonegawa teaches using a high frequency power source for plasma generation (0043). Tonegawa further teaches generating plasma between a pair of electrodes to convert the hydrogen gas to plasma and for providing the nitrogen plasma (0043, 0054, 0055, and Fig. 2).
Kelman teaches that the plasma used for decomposing molecular hydrogen can be a direct plasma in direct contact with the substrate (0028). They teach that this is accomplished by positioning the substrate between a grounded electrode and a powered electrode, which is electrically connected to a plasma power source, such as a DC power source (0028). They teach that the direct plasma may be generated between the power electrode and the grounded electrode and the substrate will be exposed to such a plasma (0028). They teach that the substrate may be placed on the grounded electrode (0029).
They do not teach providing both high frequency or RF and DC power in a single apparatus.
Iwashita teaches a film forming apparatus that includes a processing chamber, a lower electrode for mounting a substrate thereon, an upper electrode disposed to face the lower electrode, a gas supply unit, a voltage application unit, and a switching unit (abstract). They teach that the gas supply unit supplies a film forming source gas to be formed into plasma to a processing space between the upper and the lower electrode (abstract). They teach that the voltage application unit applies to the upper electrode a voltage outputted from at least one of a high frequency power supply and a DC power supply (abstract). They teach that the switching unit selectively switches the voltage to be applied to the upper electrode from a high frequency voltage out putted from the high frequency power supply, a DC voltage outputted from the DC power supply, and a super-imposed voltage in which the DC voltage is superimposed with the high frequency voltage (abstract). They teach that the variable DC power supply is connected to a pulse generator and is configured to output a negative DC voltage to the pulse generator (0046). They teach using RF power for the high frequency power (0073, 0074). Therefore, Iwashita provides an apparatus that provides both high frequency (RF) and DC power using a configuration described by Kelman.
From the teachings of Ito or Tonegawa and Iwashita, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have provided the nitrogen-containing plasma using a radio frequency voltage and generating the hydrogen radicals using a DC pulse voltage using the plasma processing apparatus of Iwashita (as required by claim 7 below) because Ito teaches using RF power for nitriding, Tonegawa teaches using a high frequency power source for nitriding, Kelman suggests using a DC source for hydrogen radical generation in removing halogen species from a substrate surface, and Iwashita provides an apparatus capable of using high frequency and DC power supplies, where RF is a high frequency power such that it will be expected to provide the desired nitrogen plasma generation and hydrogen radical generation. Therefore, the process will be performed by a plasma processing apparatus including a first electrode configured to place the substrate in the processing container, a second electrode configured to face the first electrode, and a DC power source configured to supply a DC voltage to the second electrode, where (d) includes supplying the DC pulse voltage to the second electrode by controlling the DC power source as required by claim 4.
Claims 5-7 are rejected under 35 U.S.C. 103 as being unpatentable over Ito or Tonegawa in view of Kelman and Iwashita as applied to claim 4 above, and further in view of Shindo, WO 2020121819 A1 and Miyake, US 6,335,535 B1.
The following citations for Shindo, WO 2020121819 A1 are in reference to the machine translation provided by Espacenet and the figures in the original document.
Regarding claim 5, Ito or Tonegawa in view of Kelman and Iwashita suggest the process of claim 4.
Ito teaches supplying the hydrogen gas to remove the halogen element contained in the Si-containing layer (0042).
Tonegawa teaches performing the hydrogen radical purge to remove impurity Cl or H and excessive Si from the film to result in a monoatomic layer of Si (0065 and Fig. 8B).
They do not teach that supplying the DC pulse voltage includes that an overshoot of a positive voltage is 100 V or less.
Shindo teaches a substrate processing apparatus and method (0001). They teach a processing apparatus that includes a processing chamber, a lower electrode, an upper electrode, and a power supply unit (0006). They teach that a substrate to be processed can be placed on the lower electrode, where the upper electrode is disposed opposite of the lower electrode within the processing chamber (0006 and Fig. 1). They teach that the power supply unit applies a negative DC pulse voltage to the upper electrode for generating plasma (0006 and 0031). They teach that since the electrical characteristics of the discharge path in the chamber are not ideal, the DC pulse voltage output from the pulse generator results in an overshoot that exceeds the steady voltage (0029 and 0037). They teach that the larger the absolute value of the negative voltage, the greater the amount of plasma generated (0031 and 0039). They teach that when a positive voltage is applied to the upper electrodes, it results in ions being accelerated in the chamber towards the substrate (0031, 0039, and Fig. 1). They teach that the greater the magnitude of the overshoot, the greater the amount of acceleration of ions (0039). They teach a voltage limiter can be included to limit the maximum value of the positive voltage in the DC pulse voltage output form the power supply (0046, Fig. 9, and Fig. 10).
Miyake teaches a method for implanting negative hydrogen ions by generating plasma and forming an electric field between the plasma and a substrate (abstract). They teach that negative hydrogen ions from the plasma are accelerated by using the electric field so as to implant negative hydrogen ions into a predetermined depth of a substrate (abstract). They teach that hydrogen gas is introduced into a plasma chamber and a DC voltage of about 40 V to 100 V is used to generate the hydrogen plasma (Col. 13, lines 54-64).
From the teachings of Shindo and Miyake, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Ito or Tonegawa in view of Kelman and Iwashita to have provided a voltage limiter to limit the value of the overshoot of the DC pulse voltage because Shindo teaches that when using pulsed DC voltages for plasma generation, overshoot typically occurs, where a negative pulse is used to generate plasma and a positive voltage results in the acceleration of ions towards a substrate and Miyake teaches that acceleration of hydrogen ions towards a substrate results in ions being implanted such that by limiting the positive overshoot voltage it will be expected to minimize the hydrogen implanted into the silicon layer while still providing the hydrogen radicals as desired for halogen removal. Further, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have optimized the positive voltage of the overshoot to be within the claimed range because Miyake indicates that a voltage of 40-100V is used for ion implantation and because Shindo indicates that positive voltages result in the ions being accelerated towards the substrate, where the greater the positive magnitude, the greater the acceleration such that by optimizing the positive voltage to be within the claimed range it will be expected to prevent or minimize the hydrogen ions implanted into the layer. According to MPEP 2144.05 II A, “Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. “[W]here 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.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 6, Ito or Tonegawa in view of Kelman, Iwashita, Shindo, and Miyake suggest the process of claim 5.
Shindo further teaches connecting the voltage limiter 82 to the DC power source 8 (0023, 0045, 0046, and Fig. 5).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have connected the voltage limiter to the DC power source because Shindo teaches that such an arrangement is desirable. Therefore, during (d), the DC pulse voltage will be supplied to the second electrode by controlling the DC pulse voltage by control of the voltage limiter such that the overshoot value of the positive voltage is optimized to be within the claimed range.
Regarding claim 7, Ito or Tonegawa in view of Kelman, Iwashita, Shindo, and Miyake suggest the process of claim 5. As discussed above for claim 4, the combination of Ito or Tonegawa and Iwashita provide the suggestion of using RF voltage to generate the plasma of the nitrogen-containing gas and wherein (d) includes generating the hydrogen radical by supplying the DC pulse voltage.
Conclusion
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/CHRISTINA D MCCLURE/ Examiner, Art Unit 1718