Ceramic mixture paste, porous body, electrostatic chuck, and substrate fixing device

1. A ceramic mixture paste comprising:

oxide ceramic particles;

burn-off particles that are burned off at a temperature lower than a firing temperature of the oxide ceramic particles; and

a firing aid that melts at a temperature lower than the firing temperature,

wherein the oxide ceramic particles, the burn-off particles, and the firing aid are mixed in paste form, and

a ratio of a volume of the burn-off particles to a volume of the oxide ceramic particles is more than 0% and less than or equal to 20%.

2. The ceramic mixture paste as claimed in claim 1 , wherein an average particle size of the burn-off particles is greater than an average particle size of the oxide ceramic particles.

3. The ceramic mixture paste as claimed in claim 1 , wherein

the oxide ceramic particles are aluminum oxide particles, and

the burn-off particles are polymethyl methacrylate particles.

4. A porous body comprising:

oxide ceramic particles; and

a firing aid binding the oxide ceramic particles,

wherein a porosity of the porous body is more than 30% and less than or equal to 43%.

5. An electrostatic chuck comprising:

a base including a through hole, the base being configured to attract and hold a substrate; and

a porous body in the through hole, the porous body including spherical oxide ceramic particles as a principal component, the porous body including pores that form a gas passage, the porous body having a porosity of more than 30% and less than or equal to 43%,

wherein an average size of the pores is greater than an average size of the spherical oxide ceramic particles.

6. A substrate fixing device comprising:

a baseplate; and

the electrostatic chuck as set forth in claim 5 , the electrostatic chuck being on the baseplate.