Aluminum nitride sintered body, member for semiconductor manufacturing device, and method of manufacturing aluminum nitride sintered body

Abstract

A conductive channel formed of an (Sm, Ce)Al11O18 is interconnected in the grain boundaries of aluminum nitride (AlN) particles, thereby reducing temperature dependency of volume resistivity of AlN sintered body; at the same time, the solid solution of the AlN particles is formed with at least one of C and Mg, to prevent the conductive channel from moving in AlN particles, thereby maintaining the volume resistivity within AlN particles at a high value even at a high temperature.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Exemplary embodiments of the invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the invention's scope, the exemplary embodiments of the invention will be described with additional specificity and detail through use of the accompanying drawings in which:

FIG. 1 is a schematic diagram showing a structure of an aluminum nitride sintered body according to the present invention;

FIG. 2 is a schematic diagram showing a structure of a crucible used in a heat treatment of an aluminum nitride sintered body;

FIG. 3 is a table showing evaluation results of aluminum nitride sintered bodies of Examples 1 to 18;

FIG. 4 is a table showing evaluation results of aluminum nitride sintered bodies of Comparative Examples 1 to 7;

FIG. 5 is a graph showing results of a change of volume resistivity along with a change of temperature, with respect to the aluminum nitride sintered bodies according to Examples 10 and Comparative Examples 1 to 7;

FIG. 6 is a SEM photograph of the surface of the aluminum nitride sintered body according to Comparative Example 6;

FIG. 7 is a SEM photograph of the surface of the aluminum nitride sintered body according to Example 12; and

FIG. 8 is a graph showing a change of volume resistivity of a (Sm, Ce)Al₁₁O₁₈ phase along with a change of a Sm/Ce ratio.

Claims

1. An aluminum nitride sintered body, wherein an conductive channel formed of (Sm, Ce)Al11O18 is interconnected in grain boundaries of aluminum nitride particles and aluminum nitride particles form solid solutions with at least one of C and Mg.

2. The aluminum nitride sintered body according to claim 1, wherein a molar ratio of Sm/Ce content falls within a range of more than 0.05 to less than 0.3.

3. The aluminum nitride sintered body according to claim 1, wherein a ratio of volume resistivity A at 100° C. to volume resistivity A′ at 300° C., that is, log(A/A′), desirably falls within a range of more than 1.5 to less than 2.2.

4. The aluminum nitride sintered body according to claim 1, wherein volume resistivity of the aluminum nitride sintered body at 300° C. desirably falls within the range of more than 1×109 Ω·cm to less than 2×1012 Ω·cm.

5. The aluminum nitride sintered body according to claim 1, wherein volume resistivity of the aluminum nitride sintered body at 500° C. desirably falls within the range of more than 1×108 Ω·cm to less than 1×1011 Ω·cm.

6. The aluminum nitride sintered body according to claim 1, wherein brightness according to JIS Z8721 is N4 or less.

7. The aluminum nitride sintered body according to claim 1, wherein at least one type of transition metal element selected from the group consisting of the IVA family, VA family, VIA family, VIIA family and VIIIA family of the periodical table is contained within the range of more than 0.01 wt % to less than 1.0 wt %.

8. A member for a semiconductor manufacturing device wherein at least one portion of the member is formed of the aluminum nitride sintered body according to claim 1.

9. A method of manufacturing an aluminum nitride sintered body, comprising: a step of blending at least either one of a B4C powder and a MgO powder, a (Sm, Ce)Al11O18 powder with an aluminum nitride powder to obtain a powder mixture and forming the powder mixture into a product; anda step of subjecting the formed product to hot press sintering in a nitrogen atmosphere of 1700° C. or more, thereby manufacturing the aluminum nitride sintered body.

10. A method of manufacturing an aluminum nitride sintered body, comprising: a step of raising the temperature of an aluminum nitride powder together with a metal oxide powder to a temperature of 2000° C. or more in a carbon-reducing atmosphere, thereby heat-treating the aluminum nitride powder;a step of blending at least an (Sm, Ce)Al11O18 powder with the heat-treated aluminum nitride powder to obtain a powder mixture and forming the powder mixture into a product; anda step of subjecting the formed product to hot press sintering in a nitrogen atmosphere of 1700° C. or more, thereby manufacturing the aluminum nitride sintered body.

11. A method of manufacturing an aluminum nitride sintered body, comprising: a step of raising the temperature of an aluminum nitride powder together with a metal oxide powder to a temperature of 2000° C. or more in a carbon-reducing atmosphere, thereby heat-treating the aluminum nitride powder;a step of blending at least a non-heat-treated aluminum nitride powder, a MgO powder and a (Sm, Ce)Al11O18powder with the heat-treated aluminum nitride powder to obtain a powder mixture and forming the powder mixture into a product; anda step of subjecting the formed product to hot press sintering in a nitrogen atmosphere of 1700° C. or more, thereby manufacturing the aluminum nitride sintered body.

12. A method of manufacturing an aluminum nitride sintered body, comprising: a step of raising the temperature of an aluminum nitride powder together with a metal oxide powder to a temperature of 2000° C. or more in a carbon-reducing atmosphere, thereby heat-treating the aluminum nitride powder;a step of blending at least a non-heat-treated aluminum nitride powder, a MgO powder, a Sm2O3 powder, a CeO2 powder and an Al2O3 powder with the heat-treated aluminum nitride powder to obtain a powder mixture and forming the powder mixture into a product; anda step of subjecting the formed product to hot press sintering in a nitrogen atmosphere of 1700° C. or more, thereby manufacturing the aluminum nitride sintered body.