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
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.
Claim(s) 1-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al (US 2022/0238650) in view of Wang (US 2020/0279848) and Bao et al (US 2018/0019121).
Wu et al teaches a method of forming a film on a substrate 102, comprising: heating a substrate disposed within a processing chamber to a temperature in a range of less than 550°C, such as less than 450°C ([0014]-[0031]) which clearly suggests from about 350°C to about 500°C because overlapping ranges are prima facie obvious (MPEP 2144.05). Wu et al also teaches forming a multi-layer material 105 by depositing alternating pairs of layers comprising first layer 106 and depositing a second layer 108, wherein the first layer is a doped silicon layer and suitable dopants include P dopant; and the second layer are n-type doped silicon layers wherein n-type dopants include Sb dopants ([0018]-[0022]). Wu et al also teaches each single first layer has a thickness of 20 to 200 angstrom; and each second layer has a thickness of 20 to 200 angstrom ([0020]). Wu et al also teaches the deposition process can be performed at 1 to 600 Torr and a deposition temperature of less than 500°C, such as less than 450°C ([0031]).
Wu et al does not explicitly teach the first layer is a doped P Si layer; and the second layer is a doped Sb layer. Wu et al teaches suitable dopant for the first layer is P and the second layer can be doped with Sb. It would have been obvious to one of ordinary skill in the art at the time of filing to modify Wu et al by deposition a doped Si layer and a doped Sb layer because the selection of a known material based on its suitability for its intended purpose is prima facie obvious (MPEP 2144.07).
Wu et al teaches depositing a first layer comprising P doped Si. Wu et al does not explicitly teach exposing the substrate to a soak process in a phosphorous source gas at a first chamber pressure for a period of time.
In a method of forming P doped Si layer, Wang teaches forming an epitaxial phosphorus-silicon layer comprising reaction gas may include SiH4, PH3, and AsH3, a gas pressure may be in a range of approximately 1 Torr-100 Torr, and a temperature may be in a range of approximately 500-800° C ([0033]-[0034]).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Wu et al by exposing the substrate to a soak process in a phosphorous source (PH3) gas at a first chamber pressure (1-100 Torr) for a period of time, as taught by Wang, to deposit an epitaxial phosphorus-silicon layer having a desired thickness using the conventionally known processing parameters to deposit the P doped Si layer.
The combination of Wu et al and Wang does not teach increasing the first chamber pressure to a second chamber pressure; and exposing the substrate to a deposition gas mixture comprising a chlorosilane gas and an antimony-containing source gas to deposit a silicon-containing epitaxial layer comprising antimony on the substrate.
In a method of depositing a Sb doped Si layer, Bao et al teaches a silicon source and the antimony source may react in a reaction region of the processing chamber so that the silicon antimony alloy 204 is epitaxially formed on a surface 203 of the substrate 202, using a silicon source such as dichlorosilane and an antimony source such as stibine, and a process temperature of 300°C to 600°C, and a pressure of 150 torr or 300 Torr or greater can be used to deposit an epitaxial film with a greater concentration such as 1×1020 atoms per cubic centimeter to about 5×1021 atoms per cubic centimeter, as compared to lower pressure epitaxial growth processes ([0015]-[0028]).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify the combination of Wu et al and Wang by increasing the pressure to 150 Torr or more to form the Sb doped Si layer, as taught by Bao et al, to obtain a layer with a greater Sb concentration using the conventionally known processing parameters.
It is noted that conducting routine experimentation of result effective variables, such as temperature and pressure, would have been obvious to one of ordinary skill in the art at the time of filing (MPEP 2144.05).
Referring to claim 2, the combination of Wu et al, Wang and Bao et al teaches the P doped Si layer formed at 1 Torr-100 Torr (Wang [0033]-[0034]) and a Sb doped layer at 150 Torr or more (Bao [0028]).
Referring to claim 3, the combination of Wu et al, Wang and Bao et al teaches increasing pressure; therefore, the effect of purging phosphorous gas from the processing chamber would be expected because a similar method is expected to produce a similar result.
Referring to claim 4, the combination of Wu et al, Wang and Bao et al teaches a growth rate of about 10 to 20 angstroms/min; and depositing 20-200 angstrom thick layer (Wu [0020]-[0037]); therefore, the deposition time would overlap the claimed range for example, a 20 ang/min rate for a 20 ang thick layer would take 60 seconds. Overlapping ranges are prima facie obvious (MPEP 2144.05).
Referring to claim 5, the combination of Wu et al, Wang and Bao et al teaches phosphine (PH3) ([0033]-[0034]). The selection of a known material based on its suitability for its intended purpose is prima facie obvious (MPEP 2144.07).
Referring to claim 6, the combination of Wu et al, Wang and Bao et al teaches dichlorosilane or trichlorosilane or mixtures thereof (Wu [0032], Bao [0019]). The selection of a known material based on its suitability for its intended purpose is prima facie obvious (MPEP 2144.07).
Referring to claim 7, the combination of Wu et al, Wang and Bao et al teaches SiH4, (Wang [0033]-[0034]).
Referring to claim 8, the combination of Wu et al, Wang and Bao et al teaches repeating deposition of the first layer and second layer to form a multi-material layer (Wu [0020]), which would require repeating the deposition steps, as discussed above.
Referring to claim 9, the combination of Wu et al, Wang and Bao et al teaches a silicon precursor flow rate of 1 to 1000 sccm (Wu [0032]-[0033]).; and a non-carbon antimony source flow rate of 10 to 2500 sccm (Bao [0022]). Overlapping ranges are prima facie obvious (MPEP 2144.05).
Referring to claim 10, see the remarks above. The combination of Wu et al, Wang and Bao et al teaches the first layer is an n-type Si layer and suitable n-type dopants in Sb or P; and the second layer is an n-type Si layer. It would have been obvious to one of ordinary skill in the art at the time of filing to modify the combination of Wu et al, Wang and Bao et al by making the first layer (seed) layer of Sb doped Si and the second layer of Sb and P dopant because The selection of a known material based on its suitability for its intended purpose is prima facie obvious (MPEP 2144.07) and combining equivalents known for the same purpose is prima facie obvious (MPEP 2144.06 I).
Referring to claim 11, the combination of Wu et al, Wang and Bao et al teaches 20-200 angstrom thick layer (Wu [0020]). Overlapping ranges are prima facie obvious (MPEP 2144.05).
Referring to claim 12, the combination of Wu et al, Wang and Bao et al teaches the claimed antimony sources (Wu [0033]), Bao [0021]).
Referring to claim 13, the combination of Wu et al, Wang and Bao et al teaches flow rate of chlorosilane of 1 to 1500 sccm; Sb flow rate of 10 to 2500 sccm; and flowing a diluent/carrier gas at 1 to 100 SLM (Bao [0019]-[0023]). Overlapping ranges are prima facie obvious (MPEP 2144.05). The combination of Wu et al, Wang and Bao et al teaches flowing PH3, however does not explicitly teach the flow rate. Flow rate of a precursor is a result effective variable; therefore, It would have been obvious to one of ordinary skill in the art at the time of filing to modify the combination of Wu et al, Wang and Bao et al by optimizing the phosphine flow rate to obtain the claimed range by conducting routine experimentation to obtain a desired dopant concentration.
Referring to claim 14, see the remarks above. Also, the combination of Wu et al, Wang and Bao et al teaches the substrate of Si and an optional material layer 102 of an insulating material, such as silicon oxide (Wu [0018]-[0020]). The selection of a known material based on its suitability for its intended purpose is prima facie obvious (MPEP 2144.07).
Referring to claim 15, the combination of Wu et al, Wang and Bao et al teaches an antimony concentration of 1x1020 to 5x1021 atoms/cm3 (Wu [0036]). Overlapping ranges are prima facie obvious (MPEP 2144.05).
Referring to claims 16-20, see the remarks above regarding claims 2-7.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Khazaka et al (US 2021/0254238) teaches a phosphorus doped silicon wherein phosphine is used as a phosphorous source and is provided to the reactor chamber at a flow rate of at least 100 sccm to at most 2,500 sccm (Abstract, [0071]).
Cai et al (US 2016/0087068) teaches a selective epitaxial deposition of silicon using a silicon-containing reactant gases and if the second conductivity type is n-type, the dopant gas can be, for example, PH3, AsH3, Sb3, or a combination thereof. ([0043]).
Any inquiry concerning this communication or earlier communications from the examiner should be directed to MATTHEW J SONG whose telephone number is (571)272-1468. The examiner can normally be reached Monday-Friday 10AM-6PM.
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MATTHEW J. SONG
Examiner
Art Unit 1714
/MATTHEW J SONG/ Primary Examiner, Art Unit 1714
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