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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 09/25/2025 has been entered.
Response to Arguments
Applicant’s arguments with respect to claims 1-10 and 11-20 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Objections
Amendments made in Applicant Arguments/Remarks Made in an Amendment of 09/25/2025 overcome the previous objection of claim 8 made in the Final Rejection Office Action mailed on 07/25/2025, therefore the objection of claim 8 made in the Final Rejection Office Action mailed on 07/25/2025 is withdrawn.
Claim Rejections - 35 USC § 112
Amendments made in Applicant Arguments/Remarks Made in an Amendment of 09/25/2025 overcome the previous 35 USC § 112 rejections of claims 1,10,12-13 and 20 made in the Final Rejection Office Action mailed on 07/25/2025, therefore 35 USC § 112 rejections of claims 1,10,12-13 and 20 in the Final Rejection Office Action mailed on 07/25/2025 are withdrawn.
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.
Claim 12 is 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. Regarding Claim 12, claim 12 recites the limitation, “wherein the material can be modified to provide a second etch selectivity relative to the bottom layer”. The limitation of “can be” makes it unclear if the layer is or is not modified in the final structure of the invention. Further, the phrase “can be modified to…” seems to recite the device embodiment at different process steps: one process step where the material has one etch selectivity and a second process step where the material has a second selectivity, making it unclear how to interpret the claim language. For purposes of examination Examiner has interpreted the claim as “wherein the material has a second etch selectivity relative to the bottom layer”.
Claim Rejections - 35 USC § 103
The following is a quotation of pre-AIA 35 U.S.C. 103(a) which forms the basis for all obviousness rejections set forth in this Office action:
(a) A patent may not be obtained though the invention is not identically disclosed or described as set forth in section 102, if the differences between the subject matter sought to be patented and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-2, 4-9 and 12 are rejected under pre-AIA 35 U.S.C. 103(a) as being unpatentable over Yu et al (US 2010/0279234 A1, hereinafter Yu ‘234), in view of Chen et al. (US 2017/0256711 A1, hereinafter Chen ‘711), in view of Ben-Tzur et al. (US 6,774,033 B1, hereinafter Ben-Tzur ‘033), in view of Mignot et al. (US 2016/0372334 A1, hereinafter Mignot ‘334), in view of the following arguments.
With respect to Claim 1 Yu ‘234 discloses a film stack for EUV patterning (Fig 1-10), the film stack comprising:
a dielectric (10, Fig 1, Para [0009] discloses substrate 10 includes dielectric features);
a hard mask (15, Fig 1, Para [0010]) directly disposed (disclosed in Fig 1 and Para [0010]) on the dielectric (10), the hard mask (15);
a silicon oxide layer (20, Fig 1, Para [0011]) optionally directly disposed (disclosed in Fig 1 and Para [0011]) on the hard mask (15);
a bottom layer (30, Fig 1, Para [0013]) directly disposed on the hard mask, or if the silicon oxide layer (20) is directly disposed on the hard mask (15) then the bottom layer (30) directly disposed (Para [0012] discloses layer 25, shown in Fig 1, as optional so not applying that layer results in 30 directly disposed on 20) on the silicon oxide layer (20), the bottom layer (30);
a middle layer (35, Fig 1, Para [0014]) directly disposed (disclosed in Fig 1 and Para [0014]) on the bottom layer (30), the middle layer (35), the middle layer (35) comprising one or more of a bottom anti-reflective coating (BARC), a dielectric anti-reflective coating (DARC), a doped silicon, silicon boron, or a doped boron (Para [0014] discloses 35 as developable BARC layer); and
a patterned photoresist (40, Fig 1, Para [0015]) directly disposed on the middle layer (35), the patterned photoresist (40) comprising an organic resist (Para [0015] discloses 40 as chemical amplified resist) or a metal oxide photoresist with a thickness less than or equal to about 130 Å.
But Yu ‘234 fails to explicitly disclose the dielectric (10) is a low-k dielectric.
Nevertheless, in a related endeavor, (Fig 1A of Chen ‘711), Chen ‘711 teaches a substrate (101, Fig 1A of Chen ‘711, Para [0019]) containing a low-k dielectric (103, Fig 1A of Chen ‘711, Para [0019]).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chen ‘711’s teaching of a substrate containing a low-k dielectric into Yu ‘234’s device. Yu ‘234 teaches a silicon carbide substrate containing dielectric structures but is silent on the composition of the dielectric structures. Chen ‘711 teaches a silicon carbide substrate containing a dielectric structure and further teaches the dielectric is a low-k dielectric. The ordinary artisan would have been motivated then, to modify Yu ‘234 in the manner set forth above, at least, because using a low-k dielectric would provide good protection against parasitic capacitance in the device.
As incorporated, the substrate (102) containing a low-k dielectric (103) as taught by Chen ‘711 would be used as the dielectric (10) of Yu ‘234.
Yu ‘234 as modified by Chen ‘711 fails to explicitly disclose the hard mask comprising one or more of titanium nitride (TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A.
Nevertheless, in a related endeavor (Fig 1-6 of Ben-Tzur ‘033), Ben-Tzur ‘033 teaches the hard mask (103, Fig 1 of Ben-Tzur ‘033, Col 4, Lines 5-6) comprising one or more of titanium nitride (TiN) (Col 4, Lines 5-6 of Ben-Tzur ‘033 disclose 103 as TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A (Col 3, Lines 1-3 of Ben-Tzur ‘033 discloses the thickness of TiN layer 103 as 200Å to 300Å).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Ben-Tzur ‘033’s teaching of a hard mask comprising one or more of titanium nitride (TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A into Yu ‘234 as modified by Chen ‘711’s device. Yu ‘234 as modified by Chen ‘711 teaches an etch stop layer in the euv stack. Ben-Tzur ‘033 also teaches and etch stop layer in an euv stack and teaches that TiN used in that material provides good resistance to common etchants and advantageously helps protect lower oxide layers. Further Ben-Tzur ‘033 teaches a thickness of TiN layer 103 as 200Å to 300Å. MPEP 2144.05 I states “in cases where the claimed ranges “overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists”. Therefore, the ordinary artisan would have been motivated, to modify Yu ‘234 as modified by Chen ‘711 in the manner set forth above, at least, because using the TiN would provide the advantage taught by Ben-Tzur ‘033 to protect lower layers of the stack against common etchants.
As incorporated, the TiN (103) taught by Ben-Tzur ‘033 would be used as the hard mask (15) of Yu ‘234 as modified by Chen ‘711.
But Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 fails to explicitly disclose a silicon oxide layer having a thickness less than or equal to about 200 Å.
Nevertheless, Yu ‘234 teaches a silicon oxide layer having a thickness ranging between about 600 angstroms and about 2,000 angstroms (Para [0011] of Yu ‘234). Yu ‘234 also teaches in Para [0011], “It is understood by those skilled in the art that the thickness of dielectric layer 20 is dependent upon the process node”. Therefore, because thicknesses are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired characteristics of the formed device with a silicon oxide layer having a thickness less than or equal to about 200 Å.
As incorporated, the thickness of silicon oxide layer (20) of less than or equal to 200Å would be used as the silicon oxide layer (20) of Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033.
But Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 fails to explicitly disclose the bottom layer comprising diamond-like carbon and having a thickness less than or equal to about 300 Å.
Nevertheless, in a related endeavor (Figs 1-2 of Mignot ‘334), Mignot ‘334 teaches the bottom layer (72L, Fig 1 of Mignot ‘334, Para [0033]) comprising diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and having a thickness less than or equal to about 300 A (Para [0033] discloses 72L as 100 angstrom).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Mignot ‘334’s teaching of the bottom layer comprising diamond-like carbon and having a thickness less than or equal to about 300 Å into Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033’s device. Yu ‘234 teaches the function of layer 30 is to act as a hard mask in the patterning of lower layers and that one skilled in the art would understand the thickness of that layer would be a thickness suitable to allow 30 to perform (Para [0013]). Mignot ‘033 teaches diamond like carbon with a thickness of 100Å as a known material for a hard mask in an euv stack. Therefore, the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 in the manner set forth above, at least, because diamond like carbon provides a well-known material for achieving the well-known advantage of being a good material for patterning lower layers of an euv stack.
As incorporated, the diamond like carbon and thickness of the diamond like carbon taught by Mignot ‘334 would be used as the bottom layer (30) and the thickness of (30) of Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033.
But Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly teach the middle layer having a thickness less than or equal to about 200 Å.
Nevertheless, Yu ‘234 teaches the middle layer (35) having a thickness “ranging from about 300 angstroms to about 900 angstroms” (Para [0014] of Yu ‘234). And Yu ‘234 further teaches, “the thickness of the second liner layer 35 varies according to the process node in which the semiconductor device 5 is being manufactured”. Therefore, because layer thicknesses are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired characteristics of the formed semiconductor device with the middle layer having a thickness less than or equal to about 200 Å.
As incorporated, the thickness of middle layer (35) of less than or equal to 200Å would be used as the middle layer thickness (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334.
But Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly disclose an organic resist (Para [0015] discloses 40 as chemical amplified resist) having a thickness less than or equal to about 280 Å.
Nevertheless, Yu ‘234 teaches the organic resist (40) having a thickness “a thickness ranging between about 700 angstroms to about 1,200 angstroms” (Para [0015] of Yu ‘234). Therefore, because the specific composition and thicknesses of photoresists are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired lithography characteristics of the patterned photoresist layer having a thickness less than or equal to about 280 Å.
As incorporated, the thickness of the organic patterned photoresist (40) of less than or equal to 280Å would be used as the patterned photoresist thickness (40) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334.
With respect to Claim 2 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, and Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 further discloses wherein the photoresist (40) comprises an organic resist (Para [0015] of Yu ‘334 discloses 40 as chemical amplified resist) having a thickness less than or equal to about 280 Å (as described above, the incorporated resulting thickness of photoresist layer 40 would be less than or equal to about 280Å).
With respect to Claim 4 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, and Mignot ‘334 further discloses diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and Mignot ‘334 also teaches wherein the diamond-like carbon has a density greater than 1.8 g/cc, a modulus greater than 150 GPa, and a stress less than -500 MPa. (Examiner Note: “the diamond-like carbon has a density greater than 1.8 g/cc, a modulus greater than 150 GPa, and a stress less than -500 MPa” is a functional property of the diamond-like-carbon.) (Para [0033] of Mignot ‘334 discloses diamond-like carbon which is the same material disclosed in the instant application in Para [0008] of the specification. Therefore the diamond-like carbon of Mignot ‘334 must behave the same as the diamond-like carbon of the instant application).
With respect to Claim 5 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, and Mignot ‘334 further discloses the diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and Mignot ‘334 also teaches wherein the diamond-like carbon has an sp3 carbon content in a range of from 50 percent to 90 percent. (Examiner Note: “the diamond-like carbon has an sp3 carbon content in a range of from 50 percent to 90 percent” is a functional property of the diamond-like-carbon.) (Paragraph [0033] of Mignot ‘334 discloses diamond-like carbon which is the same material disclosed in the instant application in Para [0008] of the specification. Therefore the diamond-like carbon of Mignot ‘334 must behave the same as the diamond-like carbon of the instant application).
With respect to Claim 6 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, and Mignot ‘334 further teaches wherein the low-k dielectric (30L, Fig 1 of Mignot’334, Para [0026]) comprises SiCOH (Para [0028] of Mignot’334 discloses 30L as SiCOH).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Mignot ‘334’s teaching of the low-k dielectric comprises SiCOH into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device. Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 teaches the use of a low-k dielectric, as described above, but Chen ‘711 is not specific on the material of the low-k dielectric (Para [0019] of Chen ‘711. Mignot ‘334 teaches (Para [0028]) SiCOH as a low-k dielectric. Therefore the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 with the further teaching of Mignot ‘334, at least, because the use of SiCOH provides a well-known low-k dielectric (taught by Mignot ‘334 in Para [0028]) for the use in an euv stack. Therefore the teaching of the use of SiCOH as the low-k dielectric will save the person of ordinary skill in the art R&D time to determine an appropriate low-k material and will provide good dielectric properties to the final device.
As incorporated, the use of SiCOH as the low-k dielectric layer as taught by Mignot ‘334 would be used as the low-k dielectric (10) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device.
With respect to Claim 7 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, and Yu ‘234 further teaches wherein the silicon oxide layer (20) is not optional (Yu ‘234 does not cite the layer 20 as optional) and is directly disposed (disclosed in Fig 1 and Para [0011]) on the hard mask (15), and the bottom layer (30) is directly disposed on the silicon oxide layer (20) (Para [0012] discloses layer 25, shown in Fig 1, as optional so not applying that layer results in 30 directly disposed on 20).
With respect to Claim 8 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly discloses wherein the middle layer (35) has a thickness of less than or equal to about 160 Å.
Nevertheless, Yu ‘234 teaches the middle layer (35) having a thickness “ranging from about 300 angstroms to about 900 angstroms” (Para [0014] of Yu ‘234). And Yu ‘234 further teaches, “the thickness of the second liner layer 35 varies according to the process node in which the semiconductor device 5 is being manufactured”. Therefore, because layer thicknesses are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired characteristics of the formed semiconductor device wherein the middle layer has a thickness of less than or equal to about 160 Å.
As incorporated, the thickness of middle layer (35) of less than or equal to 160Å would be used as the middle layer thickness (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334.
With respect to Claim 9 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, wherein the doped silicon comprises phosphorus doped silicon. (Claim 1 allows a selection of multiple coatings, for this examination a DARC has been selected. Therefore since Claim 9 depends to a selection in claim 1, Claim 9 is automatically satisfied as we have selected a DARC in Claim 1).
With respect to Claim 12 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1,
but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly disclose wherein the middle layer, comprises a material that has a higher etch selectivity relative to the patterned photoresist and has a first etch selectivity relative to the bottom layer, and wherein the material can be modified to provide a second etch selectivity relative to the bottom layer (Reference examiner’s interpretation of “wherein the material can be modified to provide a second etch selectivity relative to the bottom layer” as “wherein the material has a second etch selectivity relative to the bottom layer”, the second etch selectivity being greater than the first etch selectivity.
However, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, in setting up a material stack for photolithography have lower materials in the stack to have a higher etch selectivity relative to upper layers. Having lower layers with higher etch selectivity than upper layers will achieve the well-known result of forming patterns in the lower layers using the pattern of the upper layer as a mask. Further, it would be obvious to a person with skill in the art that process conditions (etchant type, temperature, etc) can be changed to manipulate the process so that the desired etched pattern can be achieved. Therefore, it would be obvious to one of ordinary skill in the art to select materials for the euv stack with relative etch selectivity’s to achieve the desired etch pattern. Further it would be obvious to one of ordinary skill in the art to adjust process conditions so that layers are etched relative to one another to achieve the desired etch patterns.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Yu ‘234 in view of Chen ‘711 in view of Ben-Tzur ‘033, in view of Mignot ‘334 and in further view of Chang et al. (US 7,482,280 B2, hereinafter Chang ‘280) in view of the following arguments.
With respect to Claim 3 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly disclose wherein the photoresist is a metal oxide photoresist with a thickness less than or equal to about 130 Å.
Nevertheless, in a related endeavor (Fig 4 of Chang ‘280), Chang ‘280 teaches wherein the photoresist (140, Fig 4 of Chang ‘280, Col 4, Lines 20-22) is a metal oxide photoresist (disclosed in Col 4, Lines 20-22 of Chang ‘280) with a thickness less than or equal to about 130 Å (Col 3, Lines 39-41 of Chang ‘280 discloses layer 140 as 5-100Å).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chang ‘280’s photoresist is a metal oxide photoresist with a thickness less than or equal to about 130 Å into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s film stack. The ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 in the manner set forth above, at least, because this metal oxide photoresist layer provides etching resistance as taught by Chang ‘280 in Col 4, Lines 34-35.
As incorporated, the metal oxide photoresist layer (140) of Chang ‘280 would be used in the patterned photoresist (40) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Yu ‘234 in view of Chen ‘711 in view of Ben-Tzur ‘033, in view of Mignot ‘334 and in further view of Briggs et al. (US 2019/0198325 A1, hereinafter Briggs ‘325), in view of the following arguments.
With respect to Claim 10 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 discloses all limitations of the film stack of claim 1, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly disclose wherein the middle layer (35) consists essentially of amorphous silicon.
Nevertheless, in a related endeavor (Fig 1-5 of Briggs ‘325), Briggs ’325 teaches the middle layer (160, Fig 1 of Briggs ‘325, Para [0020]) consists essentially of amorphous silicon (disclosed in Para [0020] of Briggs ‘325).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Briggs ‘325’s teaching of the middle layer consists essentially of amorphous silicon into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device. Yu ‘234 teaches a middle layer comprising an anti-reflective coating (Para [0014] of Yu ‘234) in an euv stack. Briggs ‘325 teaches an amorphous silicon as an antireflective material in an euv stack. Therefore, the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 in the manner set forth above, at least, because this amorphous silicon layer provides a well-known hard mask material in etch processes.
As incorporated, the teaching of using an amorphous silicon of Briggs ‘325 would be used in the middle layer (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device.
Claims 13-14 and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yu ‘234 in view of Chen ‘711 in view of Ben-Tzur ‘033 in view of Mignot ‘334 and in further view of Briggs ‘325, in view of the following arguments.
With respect to Claim 13 Yu ‘234 discloses a film stack for EUV patterning (Fig 1-10), the film stack comprising:
a dielectric (10, Fig 1, Para [0009] discloses substrate 10 includes dielectric features);
a hard mask (15, Fig 1, Para [0010]) directly disposed (disclosed in Fig 1 and Para [0010]) on the dielectric (10), the hard mask (15);
a silicon oxide layer (20, Fig 1, Para [0011]) optionally directly disposed (disclosed in Fig 1 and Para [0011]) on the hard mask (15);
a bottom layer (30, Fig 1, Para [0013]) directly disposed on the hard mask, or if the silicon oxide layer (20) is directly disposed on the hard mask (15) then the bottom layer (30) directly disposed (Para [0012] discloses layer 25, shown in Fig 1, as optional so not applying that layer results in 30 directly disposed on 20) on the silicon oxide layer (20), the bottom layer (30);
a middle layer (35, Fig 1, Para [0014]) directly disposed (disclosed in Fig 1 and Para [0014]) on the bottom layer (30), the middle layer (35), the middle layer (35); and
a patterned photoresist (40, Fig 1, Para [0015]) directly disposed on the middle layer (35), the patterned photoresist (40) comprising an organic resist (Para [0015] discloses 40 as chemical amplified resist) or a metal oxide photoresist with a thickness less than or equal to about 130 Å.
But Yu ‘234 fails to explicitly disclose the dielectric (10) is a low-k dielectric.
Nevertheless, in a related endeavor, (Fig 1A of Chen ‘711), Chen ‘711 teaches a substrate (101, Fig 1A of Chen ‘711, Para [0019]) containing a low-k dielectric (103, Fig 1A of Chen ‘711, Para [0019]).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chen ‘711’s teaching of a substrate containing a low-k dielectric into Yu ‘234’s device. Yu ‘234 teaches a silicon carbide substrate containing dielectric structures but is silent on the composition of the dielectric structures. Chen ‘711 teaches a silicon carbide substrate containing a dielectric structure and further teaches the dielectric is a low-k dielectric. The ordinary artisan would have been motivated then, to modify Yu ‘234 in the manner set forth above, at least, because using a low-k dielectric would provide good protection against parasitic capacitance in the device.
As incorporated, the substrate (102) containing a low-k dielectric (103) as taught by Chen ‘711 would be used as the dielectric (10) of Yu ‘234.
Yu ‘234 as modified by Chen ‘711 fails to explicitly disclose the hard mask comprising one or more of titanium nitride (TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A.
Nevertheless, in a related endeavor (Fig 1-6 of Ben-Tzur ‘033), Ben-Tzur ‘033 teaches the hard mask (103, Fig 1 of Ben-Tzur ‘033, Col 4, Lines 5-6) comprising one or more of titanium nitride (TiN) (Col 4, Lines 5-6 of Ben-Tzur disclose 103 as TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A (Col 3, Lines 1-3 of Ben-Tzur ‘033 discloses the thickness of TiN layer 103 as 200Å to 300Å).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Ben-Tzur ‘033’s teaching of a hard mask comprising one or more of titanium nitride (TiN) or tungsten carbide (WC) and having a thickness less than or equal to about 200 A into Yu ‘234 as modified by Chen ‘711’s device. Yu ‘234 as modified by Chen ‘711 teaches an etch stop layer in the euv stack. Ben-Tzur ‘033 also teaches and etch stop layer in an euv stack and teaches that TiN used in that material provides good resistance to common etchants and advantageously helps protect lower oxide layers. Further Ben-Tzur ‘033 teaches a thickness of TiN layer 103 as 200Å to 300Å. MPEP 2144.05 I states “in cases where the claimed ranges “overlap or lie inside ranges disclosed by the prior art a prima facie case of obviousness exists”. Therefore, the ordinary artisan would have been motivated, to modify Yu ‘234 as modified by Chen ‘711 in the manner set forth above, at least, because using the TiN would provide the advantage taught by Ben-Tzur ‘033 to protect lower layers of the stack against common etchants.
As incorporated, the TiN (103) taught by Ben-Tzur ‘033 would be used as the hard mask (15) of Yu ‘234 as modified by Chen ‘711.
But Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 fails to explicitly disclose a silicon oxide layer having a thickness less than or equal to about 200 Å.
Nevertheless, Yu ‘234 teaches a silicon oxide layer having a thickness ranging between about 600 angstroms and about 2,000 angstroms (Para [0011] of Yu ‘234). Yu ‘234 also teaches in Para [0011], “It is understood by those skilled in the art that the thickness of dielectric layer 20 is dependent upon the process node”. Therefore, because thicknesses are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired characteristics of the formed device with a silicon oxide layer having a thickness less than or equal to about 200 Å.
As incorporated, the thickness of silicon oxide layer (20) of less than or equal to 200Å would be used as the silicon oxide layer (20) of Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033.
But Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 fails to explicitly disclose the bottom layer comprising diamond-like carbon and having a thickness less than or equal to about 300 Å.
Nevertheless, in a related endeavor (Figs 1-2 of Mignot ‘334), Mignot ‘334 teaches the bottom layer (72L, Fig 1 of Mignot ‘334, Para [0033]) comprising diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and having a thickness less than or equal to about 300 A (Para [0033] of Mignot ‘334 discloses 72L as 100 angstrom).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Mignot ‘334’s teaching of the bottom layer comprising diamond-like carbon and having a thickness less than or equal to about 300 Å into Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033’s device. Yu ‘234 teaches the function of layer 30 is to act as a hard mask in the patterning of lower layers and that one skilled in the art would understand the thickness of that layer would be a thickness suitable to allow 30 to perform (Para [0013]). Mignot ‘033 teaches diamond like carbon with a thickness of 100Å as a known material for a hard mask in an euv stack. Therefore, the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033 in the manner set forth above, at least, because diamond like carbon provides a well-known material for achieving the well-known advantage of being a good material for patterning lower layers of an euv stack.
As incorporated, the diamond like carbon and thickness of the diamond like carbon taught by Mignot ‘334 would be used as the bottom layer (30) and the thickness of (30) of Yu ‘234 as modified by Chen ‘711 and further modified by Ben-Tzur ‘033.
But Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 fails to explicitly disclose the middle layer (35) comprising amorphous silicon.
Nevertheless, in a related endeavor (Fig 1-5 of Briggs ‘325), Briggs ’325 teaches the middle layer (160, Fig 1 of Briggs ‘325, Para [0020]) comprising amorphous silicon (disclosed in Para [0020] of Briggs ‘325).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Briggs ‘325’s teaching of the middle layer comprising amorphous silicon into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device. Yu ‘234 teaches a middle layer comprising an anti-reflective coating (Para [0014] of Yu ‘234) in an euv stack. Briggs ‘325 teaches an amorphous silicon as an antireflective material in an euv stack. Therefore, the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 in the manner set forth above, at least, because this amorphous silicon layer provides a well-known hard mask material in etch processes.
As incorporated, the teaching of using an amorphous silicon of Briggs ‘325 would be used in the middle layer (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334’s device.
But Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 fails to explicitly disclose an organic resist (Para [0015] discloses 40 as chemical amplified resist) having a thickness less than or equal to about 280 Å.
Nevertheless, Yu ‘234 teaches the organic resist (40) having a thickness “a thickness ranging between about 700 angstroms to about 1,200 angstroms” (Para [0015] of Yu ‘234). Therefore, because the specific composition and thicknesses of photoresists are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired lithography characteristics of the patterned photoresist layer having a thickness less than or equal to about 280 Å.
As incorporated, the thickness of the organic patterned photoresist (40) of less than or equal to 280Å would be used as the patterned photoresist thickness (40) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325.
With respect to Claim 14 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, and Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 further discloses wherein the photoresist (40) comprises an organic resist (Para [0015] of Yu ‘334 discloses 40 as chemical amplified resist) having a thickness less than or equal to about 280 Å (as described above, the incorporated resulting thickness of photoresist layer 40 would be less than or equal to about 280Å).
With respect to Claim 16 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, and Mignot ‘334 discloses diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and Mignot ‘334 also teaches wherein the diamond-like carbon has a density greater than 1.8 g/cc, a modulus greater than 150 GPa, and a stress less than -500 MPa. (Examiner Note: “the diamond-like carbon has a density greater than 1.8 g/cc, a modulus greater than 150 GPa, and a stress less than -500 MPa” is a functional property of the diamond-like-carbon.) (Para [0033] of Mignot ‘334 discloses diamond-like carbon which is the same material disclosed in the instant application in Para [0008] of the specification. Therefore the diamond-like carbon of Mignot ‘334 must behave the same as the diamond-like carbon of the instant application).
With respect to Claim 17 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, and Mignot ‘334 discloses the diamond-like carbon (Para [0033] of Mignot ‘334 discloses 72L as diamond-like-carbon) and Mignot ‘334 also teaches wherein the diamond-like carbon has an sp3 carbon content in a range of from 50 percent to 90 percent. (Examiner Note: “the diamond-like carbon has an sp3 carbon content in a range of from 50 percent to 90 percent” is a functional property of the diamond-like-carbon.) (Paragraph [0033] of Mignot ‘334 discloses diamond-like carbon which is the same material disclosed in the instant application in Para [0008] of the specification. Therefore the diamond-like carbon of Mignot ‘334 must behave the same as the diamond-like carbon of the instant application).
With respect to Claim 18 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, and Mignot ‘334 further teaches wherein the low-k dielectric (30L, Fig 1 of Mignot’334, Para [0026]) comprises SiCOH (Para [0028] of Mignot’334 discloses 30L as SiCOH).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Mignot ‘334’s teaching of the low-k dielectric comprises SiCOH into Y Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325’s device. Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 teaches the use of a low-k dielectric, as described above, but Chen ‘711 is not specific on the material of the low-k dielectric (Para [0019] of Chen ‘711. Mignot ‘334 teaches (Para [0028]) SiCOH as a low-k dielectric. Therefore the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 and further modified by Mignot ‘334 with the further teaching of Mignot ‘334, at least, because the use of SiCOH provides a well-known low-k dielectric (taught by Mignot ‘334 in Para [0028]) for the use in an euv stack. Therefore the teaching of the use of SiCOH as the low-k dielectric will save the person of ordinary skill in the art R&D time to determine an appropriate low-k material and will provide good dielectric properties to the final device.
As incorporated, the use of SiCOH as the low-k dielectric layer as taught by Mignot ‘334 would be used as the low-k dielectric (10) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325’s device.
With respect to Claim 19 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, and Yu ‘234 further teaches wherein the silicon oxide layer (20) is not optional (Yu ‘234 does not cite the layer 20 as optional) and is directly disposed (disclosed in Fig 1 and Para [0011]) on the hard mask (15), and the bottom layer (30) is directly disposed on the silicon oxide layer (20) (Para [0012] discloses layer 25, shown in Fig 1, as optional so not applying that layer results in 30 directly disposed on 20).
With respect to Claim 20 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 fails to explicitly teach the middle layer having a thickness less than or equal to about 200 Å.
Nevertheless, Yu ‘234 teaches the middle layer (35) having a thickness “ranging from about 300 angstroms to about 900 angstroms” (Para [0014] of Yu ‘234). And Yu ‘234 further teaches, “the thickness of the second liner layer 35 varies according to the process node in which the semiconductor device 5 is being manufactured”. Therefore, because layer thicknesses are known to affect photolithography results, one of ordinary skill in the art would have been led to the recited thicknesses through routine experimentation to achieve desired characteristics of the formed semiconductor device with the middle layer having a thickness less than or equal to about 200 Å.
As incorporated, the thickness of middle layer (35) of less than or equal to 200Å would be used as the middle layer thickness (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Yu ‘234 in view of Chen ‘711 in view of Ben-Tzur ‘033 in view of Mignot ‘334 in view of Briggs ‘325 and in further view of Chang ‘280, in view of the following arguments.
With respect to Claim 15 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 fails to explicitly disclose wherein the photoresist is a metal oxide photoresist with a thickness less than or equal to about 130 Å.
Nevertheless, in a related endeavor (Fig 4 of Chang ‘280), Chang ‘280 teaches wherein the photoresist (140, Fig 4 of Chang ‘280, Col 4, Lines 20-22) is a metal oxide photoresist (disclosed in Col 4, Lines 20-22 of Chang ‘280) with a thickness less than or equal to about 130 Å (Col 3, Lines 39-41 of Chang ‘280 discloses layer 140 as 5-100Å)
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Chang ‘280’s photoresist is a metal oxide photoresist with a thickness less than or equal to about 130 Å into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325’s film stack. The ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 in the manner set forth above, at least, because this metal oxide photoresist layer provides etching resistance as taught by Chang ‘280 in Col 4, Lines 34-35.
As incorporated, the metal oxide photoresist layer (140) of Chang ‘280 would be used in the patterned photoresist (40) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325.
Claim 21 is rejected under 35 U.S.C. 103 as being unpatentable over Yu ‘234 in view of Chen ‘711 in view of Ben-Tzur ‘033 in view of Mignot ‘334 in view of Briggs ‘325 and in further view of Bae et al. (US 2011/0117490 A1, hereinafter Bae ‘790), in view of the following arguments.
With respect to Claim 21 Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 discloses all limitations of the film stack of claim 13, but Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 fails to explicitly disclose wherein the middle layer comprises doped amorphous silicon.
Nevertheless, in a related endeavor (Fig 1 of Bae ‘490), Bae ‘490 teaches wherein the middle layer (103, Fig 1 of Bae ‘490, Para [0020]) comprises doped amorphous silicon. (Para [0019 and 0020] of Bae ‘490 disclose hard mask layer 103 as doped amorphous silicon).
Therefore, it would have been obvious to one with ordinary skill in the art, before the effective filing date of the claimed invention, to incorporate Bae ‘490’s teaching of wherein the middle layer comprises doped amorphous silicon into Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325’s device. Yu ‘234 teaches a middle layer comprising an anti-reflective coating (Para [0014] of Yu ‘234) in an euv stack. Bae ‘325 teaches a doped amorphous silicon as an antireflective material in an euv stack. Therefore, the ordinary artisan would have been motivated to modify Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325 in the manner set forth above, at least, because this doped amorphous silicon layer provides a well-known hard mask material in etch processes.
As incorporated, the teaching of using a doped amorphous silicon of Bae ‘490 would be used in the middle layer (35) of Yu ‘234 as modified by Chen ‘711 as modified by Ben-Tzur ‘033 as modified by Mignot ‘334 and further modified by Briggs ‘325’s device.
Conclusion
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/PAUL A BERRY/Examiner, Art Unit 2898 /JULIO J MALDONADO/Supervisory Patent Examiner, Art Unit 2898