Target of sintered compact, and method of producing the sintered compact
Provided is a target of sintered compact essentially consisting of an element of (A), an element of (B) and an element of (C) below, wherein the thermal conductivity is 2.5 W/mK or more and the oxygen concentration is 5000 ppm or more: (A) one or more chalcogenide elements selected from S, Se, and Te; (B) one or more Vb-group elements selected from Bi, Sb, As, P, and N; and (C) one or more IVb-group elements or IIIb-group elements selected from Ge, Si, C, Ga, and In. Also provided is a technology enabling stable DC sputtering, and stable and high-speed sputtering by applying high electric power, by improving heat accumulation and diffusion of volatile components due to the sputtering target having high thermal conductivity and low electric resistivity.
1. A target of sintered compact consisting of:
one or more chalcogenide elements (A) selected from the group consisting of S, Se, and Te,
one or more Vb-group elements (B) selected from the group consisting of Bi, Sb, As, P, and N,
one or more IVb-group elements or IIIb-group elements (C) selected from the group consisting of Ge, Si, C, Ga, and In, and
oxygen in an amount of 5000 wtppm or more,
wherein the target has a thermal conductivity of 2.5 W/mK or more and a structure including oxygen-deficient suboxide crystal phases of low resistance at grain boundaries within the target, and wherein the oxygen-deficient suboxide crystal phases are a suboxide of one or more elements of which the target is made.
2. The target of sintered compact according to claim 1 , wherein the amount of oxygen is 5000 wtppm or more and 30000 wtppm or less.
3. The target of sintered compact according to claim 1 , wherein the amount of oxygen is 5000 wtppm or more and 15000 wtppm or less.
4. The target of sintered compact according to claim 3 , wherein the chalcogenide element (A) is Te, the Vb-group element (B) is Sb, the IVb-group or IIIb-group element (C) is Ge, and wherein the target has a composition of elements excluding oxygen expressed as Ge 22.2 Sb 22.2 Te 55.6 (at %) and an electric resistivity of 0.30 mΩ·cm or less.
5. The target of sintered compact according to claim 4 , wherein the electric resistivity is 0.26 mΩ·cm or less.
6. The target of sintered compact according to claim 4 , wherein the electric resistivity is 0.24 mΩ·cm or less.
7. The target of sintered compact according to claim 4 , wherein the electric resistivity is 0.22 mΩ·cm or less.
8. The target of sintered compact according to claim 7 , wherein the thermal conductivity is 3.0 W/mK or more.
9. The target of sintered compact according to claim 7 , wherein the thermal conductivity is 3.2 W/mK or more.
10. The target of sintered compact according to claim 7 , wherein the thermal conductivity is 3.4 W/mK or more.
11. A deposition method to form a film on a substrate comprising the step of DC sputtering a target of a sintered compact consisting of one or more of S, Se, and Te, one or more of Bi, Sb, As, P, and N, one or more of Ge, Si, C, Ga, and In, and an oxygen concentration of 5000 wtppm or more, and wherein the target has a thermal conductivity of 2.5 W/mK or more and a structure including oxygen-deficient suboxide crystal phases of low resistance at grain boundaries within the target, and wherein the oxygen-deficient suboxide crystal phases are a suboxide of one or more elements of which the target is made.
12. The target of sintered compact according to claim 1 , wherein the chalcogenide element (A) is Te, the Vb-group element (B) is Sb, the IVb-group or IIIb-group element (C) is Ge, and wherein the target has a composition of elements, excluding oxygen, expressed as Ge 22.2 Sb 22.2 Te 55.6 (at %) and an electric resistivity of 0.30 mΩ·cm or less.
13. The target of sintered compact according to claim 12 , wherein the electric resistivity is 0.26 mΩ·cm or less.
14. The target of sintered compact according to claim 12 , wherein the electric resistivity is 0.24 mΩ·cm or less.
15. The target of sintered compact according to claim 12 , wherein the electric resistivity is 0.22 mΩ·cm or less.
16. The target of sintered compact according to claim 1 , wherein the thermal conductivity is 3.0 W/mK or more.
17. The target of sintered compact according to claim 1 , wherein the thermal conductivity is 3.2 W/mK or more.
18. The target of sintered compact according to claim 1 , wherein the thermal conductivity is 3.4 W/mK or more.
19. A sintered compact target having a composition consisting of Te, Sb, Ge, and 5000 wtppm or more of oxygen, wherein the composition excluding oxygen is expressed as Ge 22.2 Sb 22.2 Te 55.6 (at %), and wherein the target has an electric resistivity of 0.30 mΩ·cm or less, a thermal conductivity of 2.5 W/mK or more, and a structure having an average grain size of 1 to 100 μm and including oxygen-deficient GeO x suboxide crystal phases of low resistance at grain boundaries.