Detailed Correspondence
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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 2-23 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 2 recites “A system for forming an ashable hardmask (AHM) film” and then “depositing on the substrate an AHM film”, this raises antecedent issue.
This portion of claim 2 will be examined inclusive “depositing on the substrate the AHM film”
Claim 2 recites “receiving a substrate in a process chamber; exposing a semiconductor substrate …“, it is not clear whether claim 2 requires two different substrates or it should be ““receiving a substrate in a process chamber; exposing the substrate …“.
Claim 2 will be examined inclusive both interpretations.
Claims 3-17 and 19-21 depends on cancelled claim 1. Claim 18 recites “The system” without stating which claim it depends on. It is not clear the dependency of claims 3-21.
Claims 3-23 will be examined inclusive as dependent claims of claim 2.
Claim 14 recites “the method”, there is no antecedent basis of this limitation.
Claim 14 will be examined inclusive “the process”.
Claim Rejections - 35 USC § 102
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 2-5, 7, 9-10, 14-15, 18, and 20-21 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Reddy et al. (US 20150093908, from IDS, hereafter ‘908).
‘908 teaches all limitations of:
Claim 2: Methods of forming high etch selectivity, low stress ashable hard masks using plasma enhanced chemical vapor deposition are provided (abstract, including the claimed “A system for forming an ashable hardmask (AHM) film, comprising”):
a reactor 400 includes a process chamber 424 … The controller 428 executes machine-readable system control software stored in a mass storage device, loaded into memory device, and executed on processor so that the apparatus will perform a method in accordance with the present embodiments (Fig. 4, [0046], 2nd and 6th sentences, includes the claimed “a process chamber and one or more processors and memories configured for”):
PECVD processes involve generating plasma in the deposition chamber. As described further below with reference to FIG. 2 ([0019], 2nd sentence), a wafer support 418 holds a substrate 416 ([0047]), The method 200 begins by providing a substrate in a chamber in operation 202 ([0027], 2nd sentence, includes the claimed “receiving a substrate in a process chamber”);
The substrate is then exposed to a process gas including a hydrocarbon precursor in operation 204 ([0027], 6th sentence), In addition to hydrocarbon precursors, a carrier gas may be used to dilute the precursor gas flow ([0028], 2nd sentence), An AHM was deposited on a dielectric film on a substrate using C2H2 as a precursor and N2 and He as carrier gases ([0052], includes the claimed “exposing a semiconductor substrate to a process gas comprising a hydrocarbon precursor gas and inert gas”);
Provided are novel methods of depositing ashable hard masks (AHMs) by plasma enhanced chemical vapor deposition (PECVD) that decrease stress levels and increase etch selectivity for use in semiconductor processing ([0003]), includes the claimed “and depositing on the substrate an AHM film by a plasma enhanced chemical vapor deposition (PECVD) process”),
in operation 206, an ashable hard mask is deposited on the substrate by a PECVD process by igniting plasma using a dual RF plasma source that includes a low frequency (LF) component and a high frequency (HF) component ([0033], includes the claimed “wherein the process comprises: igniting a plasma generated by a dual radio frequency (RF) plasma source including a high frequency (HF) component and a low frequency (LF) component”);
Next, in operation 208, the LF power is pulsed while HF power is constant ([0034], includes the claimed “a power of the HF component is constant during deposition, and a power of the LF component is pulsed”).
Claims 3-5: An AHM was deposited on a dielectric film on a substrate using C2H2 as a precursor and N2 and He as carrier gases ([0052], includes the claimed “wherein the hydrocarbon precursor gas comprises compounds having a molecular weight of at most about 50 g/mol” of claim 3, “wherein the hydrocarbon precursor gas comprises compounds having a C:H ratio of at least 0.5” of claim 4, and “wherein the hydrocarbon precursor gas comprises acetylene (C2H2)” of claim 5).
Claim 7: Low frequency RF power refers to an RF power having a frequency between about 100 kHz and about 2 MHz ([0033], 3rd sentence, includes the claimed “wherein the LF power is provided at a frequency of less than or equal to about 2 MHz”).
Claims 9-10: In some embodiments, the LF power is pulsed at a frequency of at least about 10 Hz, or at least about 20 Hz, or at least about 100 Hz, or at least about 200 Hz ([0035], last sentence, includes the claimed “wherein the LF power is pulsed at a frequency of at least about 100 Hz” of claim 9 and “wherein the LF power is pulsed at a frequency between about 100 Hz and about 1000 Hz” of claim 10).
Claim 14: The various embodiments may be implemented on a multi-station or single station tool ([0044], 4th sentence, includes the claimed “wherein the method is performed in a multi-station reactor”).
Claim 15: In some embodiments, the deposited AHM has a modulus to stress ratio of 1:1. In some embodiments, the modulus of the deposited AHM is about 70 GPa and a stress is about -80 MPa ([0041], includes the claimed “wherein an internal stress of the AHM film is at most about −1400 MPa”).
Claim 18: the deposited AHMs have a hydrogen content of about 18%. In some embodiments, the deposited AHMs have a hydrogen content less than about 15%, less than about 10%, or less than about 5% ([0040], last sentence, includes the claimed “wherein a hydrogen concentration of the AHM film is at most about 25 atomic percent”).
Claim 20: Examples of flow rates used for four 300 mm substrates are between about 200 sccm and about 4,000 sccm of acetylene, between about 1,000 sccm and about 20,000 sccm of hydrogen, and between about 1000 sccm and about 20,000 sccm of helium ([0030], last sentence, including the claimed “wherein the inert gas is helium, substantially without any other inert gas”).
Claim 21: In operation 104, a photoresist layer is deposited, exposed, and developed in accordance with the desired etch pattern (Fig. 1, [0020]), In operation 106, the AHM is opened by etching the exposed portions of the AHM ([0021]), Next, in operation 108, the substrate layer is selectively etched to transfer the pattern to the substrate layer ([0022], includes the claimed “wherein the one or more processors and memories are further configured for patterning the AHM film and etching the patterned AHM film to define features of the AHM film in the substrate”).
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.
Claims 6, 11-12, and 16-17 are rejected under 35 U.S.C. 103 as being unpatentable over ‘908.
‘908 further teaches the limitations of:
Claim 6: Total pressure in the deposition chamber may range from between about 1 and about 20 Torr. In some embodiments, pressure is between about 5 Torr and about 10 Torr. In some embodiments, the hydrocarbon precursor is introduced at a low partial pressure, e.g., between about 0.01 Torr and about 4 Torr ([0029], includes the claimed “wherein the hydrocarbon precursor has a partial pressure between about 1-2% of the process gas”, overlapping in range, see MPEP 2144.05).
Claims 11-12: Duty cycle (the fraction of time during which the LF is on or at high power) for LF pulsing ranges from about 10% to about 70% ([0035], includes the claimed “wherein the LF power duty cycle is between about 10% and about 50%” of claim 11 and “wherein the LF power duty cycle is between about 60% and about 75%”, overlapping in range).
Claim 16: In some embodiments, the deposited AHM has a modulus to stress ratio of 1:1. In some embodiments, the modulus of the deposited AHM is about 70 GPa and a stress is about -80 MPa ([0041], includes the claimed “wherein a modulus of the AHM film is at least about 80 GPa” 1:1 ratio relative to 80 MPa is 80 Gpa).
Claim 17: Current methods to form AHMs use continuous wave RF power plasma in a PECVD process. Using continuous wave RF power results in continuous ion bombardment, which increases film density ([0025], obvious to increase the density of AHM to “wherein a density of the AHM film is at least about 1.5 g/cm3”).
Claims 8 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over ‘908, as being applied to claim 2 rejection above, in view of Subramonium et al. (US 8110493, from IDS, hereafter ‘493).
‘908 does not teach the limitations of:
Claim 8: wherein the LF power is between about 3500 W and about 6500 W per 300 mm wafer.
Claim 13: wherein the LF power has an on period for a duration of between about 200 microseconds and about 300 microseconds.
‘493 is an analogous art in the field of Pulsed PECVD Method For Modulating Hydrogen Content In Hard Mask (title), the plasma power is also pulse modulated (col. 2, line 15). ‘493 teaches that LF power of 0 to 5000 W (col. 9, line 18), The pulse characteristics can be varied by varying the pulse repetition frequency (frequency of turning the pulse ON and OFF) and duty cycle (fraction of time during which the precursor pulse is ON) (col. 4, lines 63-66), for the purpose of low hydrogen content (col. 1, lines 42-45).
Before the effective filing dates of the claimed invention, it would have been obvious to a person having ordinary skill in the art to have adopted LF power up to 5000 W and varying the pulse frequency and duty cycle, as taught by ‘493, to the method of ‘908, for the purpose of low hydrogen content, as taught by ‘493 (col. 1, lines 42-45).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over ‘908, as being applied to claim 2 rejection above, in view of Wu et al. (US 7781351, hereafter ‘351).
‘908 further teaches some limitations of:
Claim 19: wherein the process chamber has a pedestal and a showerhead, and a gap between the pedestal and the showerhead is less than about 20 mm while depositing the AHM film. ([0046]), a wafer support 418 holds a substrate 416 ([0047], includes the clamed “wherein the process chamber has a pedestal and a showerhead”).
‘908 is silent and does not teach the limitations of:
Claim 19: (wherein the process chamber has a pedestal and a showerhead), and a gap between the pedestal and the showerhead is less than about 20 mm while depositing the AHM film.
‘351 is an analogous art in the field of igniting and maintaining a plasma using dual frequency radio frequency (RF) power (col. 3, lines 3-4), including C2H2 (col. 3, line 39)ith various hydrocarbons (col. 1, lines 32-33). ‘777 teaches that he separation gap between the showerhead and the block is maintained at a distance of between about 5 mm and 100 mm (claim 13 of ‘351).
Before the effective filing dates of the claimed invention, it would have been obvious to a person having ordinary skill in the art to have a gap between the pedestal and the showerhead at 5 mm, as taught by ‘351, for its suitability with predictable results. The selection of something based on its known suitability for its intended use has been held to support a prima facie case of obviousness. MPEP 2144.07.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Applicants’ submitted IDS, US 7981777, is cited for “Methods Of Depositing Stable And Hermetic Ashable Hardmask Films” (title).
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/KEATH T CHEN/ Primary Examiner, Art Unit 1716