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 .
Response to Arguments
Applicant’s cancellation of claim 2 and addition of claim 21 is acknowledged.
Applicant’s arguments, see page 7, filed 2 January 2026, with respect to the objection to claims 18-20 have been fully considered and are persuasive. The objection to claims 18-20 has been withdrawn.
Applicant has amended claim 18 to correct the term “multilayer structures” to “multilayer structure” (plural to singular). Accordingly, the objection to claim 18 has been overcome and therefore the objection to claim 18 is withdrawn. The objection to claims 19 and 20, which was made due to their dependence from claim 18, is also withdrawn.
Applicant’s arguments, see pages 7-9, filed 2 January 2026, with respect to the rejection(s) of claim(s) 1-4, 6-10, and 18 under 35 U.S.C. 102(a)(1) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of US 20220252972 A1 (hereby referred to as Maeda).
Applicant has amended independent claims 1 and 18 to recite how the patterning of each of the layers of the mask blank is performed. Claims 1 and 18 have also been amended to recite that the intermediate layer includes at least one of Ta, Pd, Ir, Ni, Sn, Ru, and/or Au. Applicant argues that the previously cited prior art (Ohkubo) fails to disclose every limitation of claims 1 and 18, due to Ohkubo failing to teach or suggest extending the pattern including at least one opening into the hard mask layer and/or the phase shift material layer. As seen in Fig. 9A-9G of Ohkubo, a resist layer having a pattern is formed over the upper hard mask layer, and the pattern of the resist layer is transferred to the upper hard mask layer via dry etching (Ohkubo, paragraph 0152). The pattern is then transferred to the light shielding film, which is considered analogous to the claimed intermediate layer. However, Ohkubo does not continue to transfer said pattern into the underlying layers. Instead, an additional resist layer having a second pattern is formed and transferred to the underlying layers. Therefore, Applicant’s arguments are found to be persuasive and the previous rejection has been withdrawn. However, a new rejection is presented in view of US 20220252972 A1 (hereby referred to as Maeda), as explained below.
Regarding Applicant’s arguments for claim 11, Applicant argues that Olson fails to describe an intermediate layer having a composition as claimed. Olson is relied upon for the teaching of multiple intermediate layers. However, the light shielding layer of Ohkubo, which is considered to be analogous to the intermediate layer, is taught to be a tantalum-based or silicon-based material (Ohkubo, paragraph 0144). Thus, the previously cited art renders the composition of the intermediate layers prima facie obvious. Claim 11 is now rejected in view of Ohkubo in view of the newly cited Maeda and the previously cited Olson.
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.
Claim(s) 1, 3-4, 6-10, 18, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220043335 A1 (hereby referred to as Ohkubo) in view of US 20220252972 A1 (hereby referred to as Maeda).
Regarding Claims 1 and 18, Ohkubo discloses a mask blank, a transfer mask, and a semiconductor device manufacturing method. The transfer mask is manufactured by patterning a mask blank (Ohkubo, paragraph 0150). The mask blank (120) comprises a transparent substrate (1), an etching stopper film (2), a phase shift film (3), a hard mask film (11), and a light-shielding film (4) (Ohkubo, paragraph 0217-0231; paragraph 0144, and Fig. 7). A second hard mask (12) is disposed over the light-shielding film (see paragraph 0144 and Fig. 7 of Ohkubo). The light-shielding film (4) is considered analogous to the claimed “intermediate” film. The above-described mask blank thus comprises a multilayer structure including N-pairs of a hard mask layer and an intermediate layer on the hard mask layer, wherein N is 1 (and thus a natural number up to five). To produce the transfer mask, a resist film is formed over the mask blank, and a pattern to be formed in the light-shielding film (4) is written on the resist film with an electron beam, thus forming a resist pattern (Ohkubo, paragraph 0152 and Fig. 9A). Dry etching is carried out using a mixed gas with the resist pattern acting as an etching mask, thus forming a pattern in the second hard mask (12) (Ohkubo, paragraph 0152). The patterned second hark mask is used as an etching mask to pattern the light-shielding film (4) (Ohkubo, paragraph 0153). Additional etching is performed for the first hard mask layer (11) and the phase shift layer (3), using the patterned layer disposed over each of these layers as an etching mask (Ohkubo, paragraph 0154-0156 and Fig. 9A-9G). It is preferred that the light-shielding film (4), which is analogous to the intermediate layer of the instant application, is formed of a material containing silicon or tantalum (Ohkubo, paragraph 0144). The hard mask preferably contains chromium (Ohkubo, paragraph 0144), and therefore the light-shielding film and the hard mask are made of different materials.
However, Ohkubo fails to teach the extension of the pattern formed in the resist layer into the hard mask layer and the phase shift layer. Maeda teaches a mask blank and a phase shift mask. The mask blank comprises a substrate having a phase shift film, a light shielding film, and a hard mask formed upon it (Maeda, paragraph 0066 and Fig. 1). To convert the mask blank into a phase shift mask, a resist film is formed over the mask blank and patterned (Maeda, paragraph 0069). The pattern formed on the resist film is intended to be transfer to the phase shift film (Maeda, paragraph 0069). The pattern is transferred from the resist film to the phase shift film by etching each of the underlying layers using a dry etching technique (Maeda, paragraph 0069-0070 and Fig. 2A-2D). An additional pattern may be formed afterwards (Maeda, paragraph 0071).
Ohkubo and Maeda are analogous art because both references pertain to phase shift masks and their manufacture. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to extend a pattern formed in the resist layer all the way to the underlying phase shift layer, as taught by Maeda, using the mask blank taught by Ohkubo because such a patterning technique is commonly utilized in the art to pattern a phase shift layer (Maeda, paragraph 0004). Furthermore, the mask blank taught by Ohkubo can produce a phase shift mask that can reduce temperature rise caused by heat of the phase shift film that generated during exposure (Ohkubo, paragraph 0090). Thus, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to apply the known patterning technique taught by Maeda to the improved mask blank taught by Ohkubo to achieve a patterned phase shift film possessing the benefits of Ohkubo’s mask blank.
Regarding Claim 3, Ohkubo discloses that the light-shielding film (4) contains silicon or tantalum and can include a transition metal and/or metal elements other than a transition metal, such as molybdenum (Mo), tantalum (Ta), nickel (Ni), ruthenium (Ru), and palladium (Pd) (Ohkubo, paragraph 0095). A metal alloy of one or more of the above elements may also be used (Ohkubo, paragraph 0095). In some preferred embodiments, the light-shielding film contains at least one or more elements selected from silicon and tantalum (Ohkubo, paragraph 0149).
Regarding Claim 4, Ohkubo discloses an embodiment wherein the light-shielding film, which is analogous to the claimed intermediate film, is formed of silicon nitride (SiN) (Ohkubo, paragraph 0174).
Regarding Claim 6, Ohkubo discloses an embodiment wherein the hard mask layer(s) is formed of chromium nitride (CrN) (Ohkubo, paragraph 0173).
Regarding Claim 7, Ohkubo discloses that the etching stopper film (2) is formed of a material containing hafnium (Hf), aluminum (Al), and oxygen (O) (Ohkubo, paragraph 0057).
Regarding Claim 8, Ohkubo discloses that in some embodiments, the transmittance of the etching stopper film at a wavelength of 193 nm (provided by an ArF excimer laser) was 96.4% (Ohkubo, paragraph 0194), which is in the range of 95% or more.
Regarding Claim 9, Ohkubo discloses in an exemplary embodiment of the invention that the light-shielding film has a thickness of 48 nm (Ohkubo, paragraph 0174).
Regarding Claim 10, Ohkubo discloses that the phase shift film can be formed of a material containing a transition metal, silicon, and nitrogen; wherein the transition metal may be molybdenum (Mo) (Ohkubo, paragraph 0086).
Regarding Claim 21, Ohkubo teaches that the phase shift material layer is formed of a material containing a transition metal, silicon, and nitrogen (Ohkubo, paragraph 0086). The transition metal may include molybdenum (Mo) (Ohkubo, paragraph 0086). Thus, the phase shift material layer of Ohkubo’s phase shift mask may include Mo and Si.
Claim(s) 5 is rejected under 35 U.S.C. 103 as being unpatentable over US 20220043335 A1 (hereby referred to as Ohkubo) in view of US 20220252972 A1 (hereby referred to as Maeda) as applied to claim 1 above, and further in view of KR 20090004628 A (hereby referred to as KR ‘628).
Regarding Claim 5, the combination of Ohkubo and Maeda renders obvious the method of manufacturing a phase shift mask according to instant claim 1. However, Ohkubo and Maeda are silent in regards to the light-shielding layer (which is analogous to the claimed intermediate layer) comprising an organic polymer containing Si or metal particles.
KR ‘628 teaches a photomask and method of manufacturing the same. The photomask taught by KR ‘628 comprises a light-blocking member (KR ‘628, page 5 lines 5-6 of the English translation). KR ‘628 further teaches that the light-blocking member (which is considered analogous to the light-shielding layer of Ohkubo and the intermediate layer of the instant application) comprises a metal particle-containing film (KR ‘628, page 3 lines 4-8 of the English translation). Specifically, the metal particle-containing film is formed by polymerizing a radically-polymerizable compound and providing metal ions or metal salts to the polymer layer (KR ‘628, page 5 lines 15- 21). Thus, the light-shielding film obtained is a polymeric material containing metal particles.
Ohkubo, Maeda, and KR ‘628 are analogous art because each reference pertains to masks and their manufacture. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use an organic polymer containing metal particles, as taught by KR ‘628, as the light-shielding layer in the mask blank used in the method of manufacturing the photomask obtained by combining the teachings of Ohkubo and Maeda because a light-shielding film including an organic polymer containing metal particles exhibits excellent adhesion and light-shielding properties (KR ‘628, page 40 lines 3-7 of the English translation), thus making it desirable for use as a light-shielding layer.
Claim(s) 11-14, 16-17, and 19 are rejected under 35 U.S.C. 103 as being unpatentable over US 20220043335 A1 (hereby referred to as Ohkubo) in view of US 20220252972 A1 (hereby referred to as Maeda) and US 20110159411 A1 (hereby referred to as Olson).
Regarding Claims 11 and 19, Ohkubo discloses a mask blank, a transfer mask, and a semiconductor device manufacturing method. The transfer mask is manufactured by patterning a mask blank (Ohkubo, paragraph 0150). The mask blank (120) comprises a transparent substrate (1), an etching stopper film (2), a phase shift film (3), a hard mask film (11), and a light-shielding film (4) (Ohkubo, paragraph 0217-0231; paragraph 0144, and Fig. 7). A second hard mask (12) is disposed over the light-shielding film (see paragraph 0144 and Fig. 7 of Ohkubo). The light-shielding film (4) is considered analogous to the claimed “intermediate” film. The above-described mask blank thus comprises a multilayer structure including N-pairs of a hard mask layer and an intermediate layer on the hard mask layer, wherein N is 1 (and thus a natural number up to five). To produce the transfer mask, a resist film is formed over the mask blank, and a pattern to be formed in the light-shielding film (4) is written on the resist film with an electron beam, thus forming a resist pattern (Ohkubo, paragraph 0152 and Fig. 9A). Dry etching is carried out using a mixed gas with the resist pattern acting as an etching mask, thus forming a pattern in the second hard mask (12) (Ohkubo, paragraph 0152). The patterned second hark mask is used as an etching mask to pattern the light-shielding film (4) (Ohkubo, paragraph 0153). Additional etching is performed for the first hard mask layer (11) and the phase shift layer (3), using the patterned layer disposed over each of these layers as an etching mask (Ohkubo, paragraph 0154-0156 and Fig. 9A-9G). It is preferred that the light-shielding film (4), which is analogous to the intermediate layer of the instant application, is formed of a material containing silicon or tantalum (Ohkubo, paragraph 0144). The hard mask preferably contains chromium (Ohkubo, paragraph 0144), and therefore the light-shielding film and the hard mask are made of different materials.
However, Ohkubo fails to teach the extension of the pattern formed in the resist layer into the hard mask layer and the phase shift layer. Maeda teaches a mask blank and a phase shift mask. The mask blank comprises a substrate having a phase shift film, a light shielding film, and a hard mask formed upon it (Maeda, paragraph 0066 and Fig. 1). To convert the mask blank into a phase shift mask, a resist film is formed over the mask blank and patterned (Maeda, paragraph 0069). The pattern formed on the resist film is intended to be transfer to the phase shift film (Maeda, paragraph 0069). The pattern is transferred from the resist film to the phase shift film by etching each of the underlying layers using a dry etching technique (Maeda, paragraph 0069-0070 and Fig. 2A-2D). An additional pattern may be formed afterwards (Maeda, paragraph 0071).
However, Ohkubo and Maeda are silent in regards to multiple sets of hard masks and light-shielding layers. Olson teaches phase shift photomasks and patterning methods. The phase shift photomask blank includes multiple hard mask regions (Olson, paragraph 0023). The hard mask regions are separated by intermediate layers (Olson, paragraph 0023 and Fig. 2-3). Olson teaches that the inclusion of multiple hard mask regions allows for separate patterning of the underlying regions (Olson, paragraph 0023). Further, Olson teaches that patterning using multiple hard mask regions allows for patterns with smaller feature sizes to be produced, compared to if a singular hard mask structure was utilized (Olson, paragraph 0009 and 0023).
Ohkubo, Maeda, and Olson are analogous art because each reference pertains to photomask manufacturing. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to extend a pattern formed in the resist layer all the way to the underlying phase shift layer, as taught by Maeda, using the mask blank taught by Ohkubo because such a patterning technique is commonly utilized in the art to pattern a phase shift layer (Maeda, paragraph 0004). Furthermore, the mask blank taught by Ohkubo can produce a phase shift mask that can reduce temperature rise caused by heat of the phase shift film that generated during exposure (Ohkubo, paragraph 0090). Thus, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to apply the known patterning technique taught by Maeda to the improved mask blank taught by Ohkubo to achieve a patterned phase shift film possessing the benefits of Ohkubo’s mask blank. Additionally, it would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use multiple hard mask structures, as taught by Olson, using the hard mask structure comprising a hard mask with a light-shielding layer disposed above the hard mask, as taught by Ohkubo, because the inclusion of multiple hard mask structures allows for separate patterning to be performed (Olson, paragraph 0023) and yields smaller feature sizes (and thus finer resolution) than using a singular hard mask structure (Olson, paragraph 0009 and 0023). The proposed combination would yield the invention according to instant claim 11 and an embodiment of instant claim 18 wherein N is 3 or more.
Regarding Claim 12, Ohkubo discloses an embodiment wherein the hard mask layer(s) is formed of chromium nitride (CrN) (Ohkubo, paragraph 0173).
Regarding Claim 13, Ohkubo discloses that the light-shielding film (4) contains silicon and can include a transition metal and/or metal elements other than a transition metal, such as molybdenum (Mo), tantalum (Ta), nickel (Ni), ruthenium (Ru), and palladium (Pd) (Ohkubo, paragraph 0095). A metal alloy of one or more of the above elements may also be used (Ohkubo, paragraph 0095). In some preferred embodiments, the light-shielding film contains at least one or more elements selected from silicon and tantalum (Ohkubo, paragraph 0149).
Regarding Claim 14, Ohkubo discloses an embodiment wherein the light-shielding film, which is analogous to the claimed intermediate film, is formed of silicon nitride (SiN) (Ohkubo, paragraph 0174).
Regarding Claim 16, Ohkubo discloses that the etching stopper film (2) is formed of a material containing hafnium (Hf), aluminum (Al), and oxygen (O) (Ohkubo, paragraph 0057).
Regarding Claim 17, Ohkubo discloses that the phase shift film can be formed of a material containing a transition metal, silicon, and nitrogen; wherein the transition metal may be molybdenum (Mo) (Ohkubo, paragraph 0086).
Claim(s) 15 is rejected under 35 U.S.C. 103 as being unpatentable over US 20220043335 A1 (hereby referred to as Ohkubo) in view of US 20220252972 A1 (hereby referred to as Maeda) and US 20110159411 A1 (hereby referred to as Olson) as applied to claim 12 above, and further in view of KR 20090004628 A (hereby referred to as KR ‘628).
Regarding Claim 15, the combination of Ohkubo, Maeda, and Olson renders obvious the method of manufacturing a phase shift mask according to instant claim 11. Ohkubo further discloses that the hard mask layers are made of chromium nitride (CrN) (Ohkubo, paragraph 0173).
However, Ohkubo, Maeda, and Olson are silent in regards to the light-shielding layer (which is analogous to the claimed intermediate layer) comprising an organic polymer containing Si or metal particles. KR ‘628 teaches a photomask and method of manufacturing the same. The photomask taught by KR ‘628 comprises a light-blocking member (KR ‘628, page 5 lines 5-6 of the English translation). KR ‘628 further teaches that the light-blocking member (which is considered analogous to the light-shielding layer of Ohkubo and the intermediate layer of the instant application) comprises a metal particle-containing film (KR ‘628, page 3 lines 4-8 of the English translation). Specifically, the metal particle-containing film is formed by polymerizing a radically-polymerizable compound and providing metal ions or metal salts to the polymer layer (KR ‘628, page 5 lines 15- 21). Thus, the light-shielding film obtained is a polymeric material containing metal particles.
Ohkubo, Maeda, Olson, and KR ‘628 are analogous art because each reference pertains to photomasks and their manufacture. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use an organic polymer containing metal particles, as taught by KR ‘628, as the light-shielding layer in the mask blank used in the method of manufacturing the photomask obtained by combining Ohkubo, Maeda, and Olson because a light-shielding film including an organic polymer containing metal particles exhibits excellent adhesion and light-shielding properties (KR ‘628, page 40 lines 3-7 of the English translation), thus making it desirable for use as a light-shielding layer.
Claim(s) 20 is rejected under 35 U.S.C. 103 as being unpatentable over US 20220043335 A1 (hereby referred to as Ohkubo) in view of US 20220252972 A1 (hereby referred to as Maeda) as applied to claim 18 above, and further in view of US 20020068229 A1 (hereby referred to as Westerman).
Regarding Claim 20, the combination of Ohkubo and Maeda renders obvious a method of manufacturing a phase shift photomask according to instant claim 18. The phase shift photomask includes an etching stopper layer disposed on the transparent substrate (Ohkubo, paragraph 0217-0231; paragraph 0144, and Fig. 7). However, Ohkubo and Maeda are silent in regards to the etching stopper layer being patterned.
Westerman teaches attenuated phase shift masks and their manufacture. The phase shift mask taught by Westerman comprises a transparent substrate containing an etch stop layer disposed over the substrate (Westerman, paragraph 0028-0029). A phase shift layer is disposed over the etch stop layer (Westerman, paragraph 0029 and Fig. 2). It is apparent that this layout is analogous to that of Ohkubo and the instant application. Westerman further teaches that the etch stop layer can comprise substantially transparent materials such as Al2O3 (Westerman, paragraph 0038). In an optional step, the etch stop layer is etched in a patternwise manner (Westerman, paragraph 0050 and Fig. 5C). In some embodiments, such as when the transmission of the etch stop layer is acceptable, the patterning of the etch stop layer is omitted (Westerman, paragraph 0051).
Ohkubo, Maeda, and Westerman are analogous art because each reference pertains to phase shift masks and their manufacture. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to pattern the etching stopper layer, as taught by Westerman, in the method of manufacturing a phase shift mask obtained by combining the teachings of Ohkubo and Maeda because the patterning of the etching stopper layer improves the light transmission of the phase shift mask when the etching stopper film is not produced of a highly optically transparent material having low thickness (Westerman, paragraph 0051-0052).
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/JAYSON D COSGROVE/Examiner, Art Unit 1737
/JONATHAN JOHNSON/Supervisory Patent Examiner, Art Unit 1734
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