Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
73 words
A sputtering target formed of refractory metallic silicide having a composition MSi x , said MSi x comprising: an MSi₂ phase in the form of particles where M is at least one refractory metal selected from a group consisting of tungsten, molybdenum, titanium, zirconium, hafnium, niobium and tantalum; and an Si phase provided as a matrix phase, wherein interface layers having a predetermined thickness exist between the MSi₂ phase and the Si phase.
Claim 2
Dependent Claim
73 words
A sputtering target formed of refractory metallic silicide having a composition MSi x , said MSi x comprising: an MSi₂ phase in the form of particles where M is at least one refractory metal selected from a group consisting of tungsten, molybdenum, titanium, zirconium, hafnium, niobium and tantalum; and an Si phase provided as a matrix phase, wherein interface layers having a predetermined thickness exist between the MSi₂ phase and the Si phase.
Claim 3
Dependent Claim
22 words
A sputtering target according to claim 1, wherein a value X of the composition formula MSi x ranges from 2.0 to 4.0.
Claim 4
Dependent Claim
38 words
A sputtering target according to claim 1 or 2, wherein a thickness of the interface layers formed at the interfaces between the MSi₂ phase and the Si phase ranges from 100 to 5000 Å (10 to 500 nm).
Claim 5
Dependent Claim
47 words
A sputtering target according to any of claims 1 to 3, wherein a spatial dispersion of the composition formula MSi x is within a range of ±0.05 in terms of Si/M atomic ratio, and a density ratio of the target is equal to or larger than 99%.
Claim 6
Dependent Claim
41 words
A sputtering target according to any of claims 1 to 4, wherein the Si phase contains at least one element selected from a group consisting of B, P, Sb and As, and has an electrical resistivity of 0.01 to 1 Ωcm.
Claim 7
Dependent Claim
36 words
A sputtering target according to any of claims 1 to 5, wherein a roughness of a surface portion of the sputtering target expressed as center line roughness (Ra) is equal to or less than 0.05 µm.
Claim 8
Dependent Claim
34 words
A sputtering target according to any of claims 1 to 6, wherein a residual compressive stress in a surface portion of said target is equal to or less than 5 kg/mm² (≈ 5 daN/mm²).
Claim 9
Dependent Claim
61 words
A sputtering target according to any of claims 1 to 7, wherein said target is in the form of a plate and is formed of refractory metallic silicide expressed by a composition formula MSi x , said target having a composition distribution such that a value X increases from a peripheral portion of the target toward a center of the same.
Claim 10
Dependent Claim
39 words
A sputtering target according to any of claims 1 to 8, wherein the composition is set in such a manner that a value X of the composition formula MSi x continuously changes within a range of 2.0 to 4.0.
Claim 11
Dependent Claim
62 words
A sputtering target according to any of claims 1 to 9, wherein the target is formed of refractory metallic silicide expressed by a composition formula MSi x , said target having a composition distribution such that a value X ranges from 2.0 to 4.0 and continuously decreases from a portion of a region eroded by sputtering toward a periphery of the same.
Claim 12
Independent Claim
166 words
A method of manufacturing sputtering target formed of refractory metallic silicide having a composition in which an MSi₂ phase in the form of particles where M is at least one refractory metal selected from a group consisting of W, Mo, Ti, Zr, Hf, Nb and Ta is dispersed in an Si ma trix phase and in which interface layers are formed at the interfaces between the MSi₂ phase and the Si phase, said method comprising the steps of: (1) preparing a mixed powder by mixing an M powder and an Si powder at an Si/M atomic ratio of 2.0 to 4.0; (2) packing the mixed powder in a mold and rapidly heating up the mixed powder in a high vacuum under a high pressing pressure to form a pressed compact in which an MSi₂ phase is synthesized; and (3) sintering the pressed compact by heating at a temperature immediately below the eutectic temperature in a low vacuum or inert gas atmosphere under a high pressing pressure.
Claim 13
Independent Claim
166 words
A method of manufacturing sputtering target formed of refractory metallic silicide having a composition in which an MSi₂ phase in the form of particles where M is at least one refractory metal selected from a group consisting of W, Mo, Ti, Zr, Hf, Nb and Ta is dispersed in an Si ma trix phase and in which interface layers are formed at the interfaces between the MSi₂ phase and the Si phase, said method comprising the steps of: (1) preparing a mixed powder by mixing an M powder and an Si powder at an Si/M atomic ratio of 2.0 to 4.0; (2) packing the mixed powder in a mold and rapidly heating up the mixed powder in a high vacuum under a high pressing pressure to form a pressed compact in which an MSi₂ phase is synthesized; and (3) sintering the pressed compact by heating at a temperature immediately below the eutectic temperature in a low vacuum or inert gas atmosphere under a high pressing pressure.
Claim 14
Dependent Claim
47 words
A method of manufacturing a sputtering target according to claim 11, wherein a spatial dispersion of the composition formula MSi x is within a range of ±0.05 in terms of Si/M atomic ratio, and a density ratio of the target is equal to or larger than 99%.
Claim 15
Dependent Claim
32 words
A method of manufacturing a sputtering target wherein, in the step (2) set forth in claim 11, a central portion of the mixed powder packed in the mold is rapidly heated up.
Claim 16
Dependent Claim
75 words
A method of manufacturing a sputtering target wherein , in the step (2) set forth in claim 11, the refractory metal M powder and the Si powder are mixed to prepare at least two mixed powders of different mixing ratios, the mixed powder having a larger Si content being packed in a central portion of the mold while the mixed powder having a smaller Si content being packed at a peripheral portion of the mold.