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 arguments, see pages 5-6, filed 26 May 2026, with respect to the rejections of claims 1 and 9 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejections of claims 1 and 9 under 35 U.S.C. 103 have been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of US 20040033699 A1 (hereby referred to as Hector) and US 20180031965 A1 (hereby referred to as Jindal).
Applicant has amended independent claim 1 to recite that the coating film is formed of a compound including at least one of silicon dioxide, aluminum oxide, or titanium oxide. Independent claim 9 has been amended to recite that the absorption portion is formed of a compound including tin oxide. Claims 1 and 9 also have been amended to recite that the coating film is an atomic layer that is uniformly formed with the thickness of the coating film being within ±2 nm of the average thickness of the coating film. The amendments made to the claims reflect Option B-2 as presented to the Examiner during the telephonic interview conducted with Applicant’s representative on 14 May 2026. As noted in the interview summary filed 19 May 2026, the amendments overcome the current prior art rejections (e.g. rejection of claim 1 in view of Yu and Okamura and rejection of claim 9 in view of Yu and Shoki), due to the cited art failing to teach or disclose each of the features recited by the claims, as amended. However, a new rejection of claim 1 is presented in view of US 20040033699 A1 (hereby referred to as Hector) and a new rejection of claim 9 is presented in view of US 20040033699 A1 (hereby referred to as Hector) and US 20180031965 A1 (hereby referred to as Jindal), as explained below.
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, and 8 are rejected under 35 U.S.C. 103 as being unpatentable over US 20170351169 A1 (hereby referred to as Yu) in view of US 20040033699 A1 (hereby referred to as Hector).
Regarding Claims 1, 4, and 8, Yu discloses a high durability extreme ultraviolet photomask. One embodiment of Yu’s invention is demonstrated by Fig. 4 of Yu (Yu, paragraph 0033). The reflective mask disclosed by Yu comprises a substrate (102), a reflective multilayer (RML, 104), and an absorber layer (108), wherein the absorber layer does not fully cover the reflective multilayer (Yu, paragraph 0033). Over the absorber layer and the reflective multilayer is a capping layer (162) (Yu, paragraph 0033). The capping layer is analogous to the coating film recited by instant claim 1. The capping layer is formed over the absorber layer, but may also be deposited on the sidewalls of the absorber layer (Yu, paragraph 0034). The capping layer may be an alloy containing ruthenium, or may be a titanium, silicon, or zirconium doped by one of oxygen and nitrogen (Yu, paragraph 0034). For instance, the capping layer may be silicon dioxide (SiO2) or titanium oxide (TiO2) (Yu, paragraph 0046). The capping layer (162) is stated to be equivalent to the capping layer (106) used in other embodiments (Yu, paragraphs 0034). Yu further discloses that the capping layer (106) has a thickness that is designed to provide anti-oxidation and etching resistance without degrading the EUV reflectivity of the mask (Yu, paragraph 0027). The thickness of the capping layer ranges between 2.5 nm and 4 nm (Yu, paragraph 0053), which overlaps with the thickness recited by instant claim 1.
However, Yu is silent in regards to the protective capping layer being formed by atomic layer deposition (ALD). Hector teaches a method of making an integrated circuit using an EUV mask formed by atomic layer deposition. The mask used in the method taught by Hector is a reflective EUV mask (Hector, paragraph 0011). The mask comprises a substrate and a reflective multilayer stack (Hector, paragraph 0012). An absorption pattern is formed on the reflective layer (Hector, paragraph 0022). Hector further teaches that the layers of the reflective EUV mask are formed using ALD (Hector, paragraph 0011, 0016, and 0021). By using ALD to form the layers, the thickness of each layer is very accurate and a high degree of thickness uniformity may be obtained (Hector, paragraph 0021).
Yu and Hector are analogous art because both references pertain to reflective masks. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to form the capping layer using ALD, as taught by Hector, to make the mask disclosed by Yu because ALD yields a high degree of thickness uniformity (Hector, paragraph 0021), and thus the optical properties of the capping layer and the effectiveness of the capping layer to protect the underlying layers from damage do not fluctuate greatly in the layer. Furthermore, whilst Yu and Hector do not explicitly disclose an extinction coefficient of the capping layer, it would be expected by those having ordinary skill in the art that the silicon dioxide or titanium oxide capping layer disclosed by Yu would have an extinction coefficient of 0.04 or less because, per paragraph 0024 of the instant application’s specification, materials such as silicon dioxide and oxides of titanium exhibit an extinction coefficient of 0.04 or less.
Regarding Claim 3, Yu discloses that the absorber layer includes at least one of chromium (Cr), chromium oxide (CrO), titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), titanium (Ti), or aluminum-copper (Al—Cu), palladium, tantalum boron nitride (TaBN), aluminum oxide (AlO), molybdenum (Mo), and other suitable materials (Yu, paragraph 0029). Tantalum is utilized as the absorber layer material in a preferred embodiment (Yu, paragraph 0029).
Claim(s) 5 is rejected under 35 U.S.C. 103 as being unpatentable over US 20170351169 A1 (hereby referred to as Yu) in view of US 20040033699 A1 (hereby referred to as Hector) as applied to claim 1 above, and further in view of US 20120164846 A1 (hereby referred to as HA).
Regarding Claim 5, the combination of Yu and Hector renders obvious a reflective mask comprising a substrate, a reflective portion, an absorption portion, and a coating film, as discussed above. Hector teaches the formation of reflective mask layers using atomic layer deposition (ALD) and further teaches that ALD provides a high degree of layer thickness uniformity (Hector, paragraph 0021).
However, Yu and Hector are silent in regards to an atomic layer deposition process that uses a metal hydride, metal halide, or organometallic compound as the material gas in an ALD process. HA teaches a method of forming a metal oxide hardmask. In the method, HA provides a mask template, which is a substrate with layers formed upon it, and deposits, using atomic layer deposition (ALD), a metal oxide hardmask on the template (HA, paragraph 0020). In the ALD process, a precursor to the metal oxide is provided along with a reactant gas (HA, paragraph 0055). In the example provided by HA, the metal oxide hardmask is a titanium oxide (TiO2), and the precursor chosen is a titanium alkoxide or an alkylamino titanium (HA, paragraph 0055). The precursor, which is a material gas, is an organometallic compound.
Yu, Hector, and HA are analogous art because each reference pertains to mask manufacturing. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use an organometallic material gas in an ALD process, as taught by HA, to produce the mask obtained by combining Yu and Hector because ALD is a form of chemical vapor deposition that provides films having better mechanical strength properties and chemical resistance (HA, paragraph 0041-0042) and because the use of an organometallic compound can provide a higher film growth rate and a lower steric hindrance, resulting in more adsorption sites for the precursor and thus improving the effectiveness of the ALD process (see HA, paragraph 0055).
Claim(s) 9-11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over US 20170351169 A1 (hereby referred to as Yu) in view of US 20040033699 A1 (hereby referred to as Hector) and US 20180031965 A1 (hereby referred to as Jindal).
Regarding Claims 9-11 and 13, Yu discloses a high durability extreme ultraviolet photomask. One embodiment of Yu’s invention is demonstrated by Fig. 4 of Yu (Yu, paragraph 0033). The reflective mask disclosed by Yu comprises a substrate (102), a reflective multilayer (RML, 104), and an absorber layer (108), wherein the absorber layer does not fully cover the reflective multilayer (Yu, paragraph 0033). Over the absorber layer and the reflective multilayer is a capping layer (162) (Yu, paragraph 0033). The capping layer is analogous to the coating film recited by instant claim 1. The capping layer is formed over the absorber layer, but may also be deposited on the sidewalls of the absorber layer (Yu, paragraph 0034). Yu discloses that the absorber layer includes at least one of chromium (Cr), chromium oxide (CrO), titanium nitride (TiN), tantalum nitride (TaN), tantalum (Ta), titanium (Ti), or aluminum-copper (Al—Cu), palladium, tantalum boron nitride (TaBN), aluminum oxide (AlO), molybdenum (Mo), and other suitable materials (Yu, paragraph 0029). Tantalum is utilized as the absorber layer material in a preferred embodiment (Yu, paragraph 0029). The capping layer may be an alloy containing ruthenium, or may be a titanium, silicon, or zirconium doped by one of oxygen and nitrogen (Yu, paragraph 0034). For instance, the capping layer may be silicon dioxide (SiO2) or titanium oxide (TiO2) (Yu, paragraph 0046). The capping layer (162) is stated to be equivalent to the capping layer (106) used in other embodiments (Yu, paragraphs 0034). Yu further discloses that the capping layer (106) has a thickness that is designed to provide anti-oxidation and etching resistance without degrading the EUV reflectivity of the mask (Yu, paragraph 0027). The thickness of the capping layer ranges between 2.5 nm and 4 nm (Yu, paragraph 0053), which overlaps with the thickness recited by instant claim 9.
However, Yu is silent in regards to the protective capping layer being formed by atomic layer deposition (ALD). Hector teaches a method of making an integrated circuit using an EUV mask formed by atomic layer deposition. The mask used in the method taught by Hector is a reflective EUV mask (Hector, paragraph 0011). The mask comprises a substrate and a reflective multilayer stack (Hector, paragraph 0012). An absorption pattern is formed on the reflective layer (Hector, paragraph 0022). Hector further teaches that the layers of the reflective EUV mask are formed using ALD (Hector, paragraph 0011, 0016, and 0021). By using ALD to form the layers, the thickness of each layer is very accurate and a high degree of thickness uniformity may be obtained (Hector, paragraph 0021).
However, Yu and Hector are silent in regards to the absorption layer including tin oxide. Jindal teaches extreme ultraviolet mask blanks with an alloy absorber. The mask taught by Jindal is a reflective EUV mask comprising a substrate, a reflective multilayer stack, an absorber layer, and a capping layer (Jindal, paragraph 0048). The absorber layer is formed of two absorber materials (Jindal, paragraph 0071). Suitable materials for the absorber layer include tin dioxide (SnO2), tin oxide (SnO), chromium (Cr), tantalum (Ta), tantalum nitride (TaN), and the like (Jindal, paragraph 0071). The Examiner notes that chromium, tantalum, and tantalum nitride are disclosed by Yu to be suitable absorption layer materials (Yu, paragraph 0047).
Yu, Hector, and Jindal are analogous art because each reference pertains to reflective masks. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to form the capping layer using ALD, as taught by Hector, to make the mask disclosed by Yu because ALD yields a high degree of thickness uniformity (Hector, paragraph 0021), and thus the optical properties of the capping layer and the effectiveness of the capping layer to protect the underlying layers from damage do not fluctuate greatly in the layer. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use tin oxide, as taught by Jindal, in the absorber layer disclosed by Yu because tin oxide is taught to be a functional equivalent to tantalum-based compounds for use in light absorbing layers for reflective photomasks (Jindal, paragraph 0071). Yu utilizes tantalum-based absorber layers (see Yu, paragraph 0029 and 0047), and thus per MPEP 2144.06 II., a prima facie case of obviousness exists. Furthermore, whilst Yu, Hector, and Jindal do not explicitly disclose an extinction coefficient of the capping layer, it would be expected by those having ordinary skill in the art that the silicon dioxide or titanium oxide capping layer disclosed by Yu would have an extinction coefficient of 0.04 or less because, per paragraph 0024 of the instant application’s specification, materials such as silicon dioxide and oxides of titanium exhibit an extinction coefficient of 0.04 or less.
Claim(s) 12 is rejected under 35 U.S.C. 103 as being unpatentable over US 20170351169 A1 (hereby referred to as Yu) in view of US 20040033699 A1 (hereby referred to as Hector) and US 20180031965 A1 (hereby referred to as Jindal) as applied to claim 11 above, and further in view of US 20120164846 A1 (hereby referred to as HA).
Regarding Claim 12, the combination of Yu, Hector, and Jindal renders obvious a reflective mask comprising a substrate, a reflective portion, an absorption portion, and a coating film, as discussed above. Hector teaches the formation of reflective mask layers using atomic layer deposition (ALD) and further teaches that ALD provides a high degree of layer thickness uniformity (Hector, paragraph 0021).
However, Yu, Hector, and Jindal are silent in regards to an atomic layer deposition process that uses a metal hydride, metal halide, or organometallic compound as the material gas in an ALD process. HA teaches a method of forming a metal oxide hardmask. In the method, HA provides a mask template, which is a substrate with layers formed upon it, and deposits, using atomic layer deposition (ALD), a metal oxide hardmask on the template (HA, paragraph 0020). In the ALD process, a precursor to the metal oxide is provided along with a reactant gas (HA, paragraph 0055). In the example provided by HA, the metal oxide hardmask is a titanium oxide (TiO2), and the precursor chosen is a titanium alkoxide or an alkylamino titanium (HA, paragraph 0055). The precursor, which is a material gas, is an organometallic compound.
Yu, Hector, Jindal, and HA are analogous art because each reference pertains to mask manufacturing. It would have been obvious to one having ordinary skill in the art before the filing date of the instant application to use an organometallic material gas in an ALD process, as taught by HA, to produce the mask obtained by combining Yu, Hector, and Jindal because ALD is a form of chemical vapor deposition that provides films having better mechanical strength properties and chemical resistance (HA, paragraph 0041-0042) and because the use of an organometallic compound can provide a higher film growth rate and a lower steric hindrance, resulting in more adsorption sites for the precursor and thus improving the effectiveness of the ALD process (see HA, paragraph 0055).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 20170038671 A1 (hereby referred to as Takai) teaches a capping layer formed on an EUV reflective mask that has a uniform thickness (Takai, paragraph 0065). US 20070081229 A1 (hereby referred to as Shiraishi) teaches uniform thickness capping layers formed on EUV reflective mirrors. Takai and Shiraishi provide teaching that capping layers of uniform thickness (i.e. the thickness is within ±2 nm of the average thickness of the capping layer) are commonplace in the art of EUV reflective masks.
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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