| CPC H01L 21/6833 (2013.01) | 3 Claims |
|
1. An electrostatic chuck comprising:
a ceramic dielectric substrate having a first major surface for mounting a suction target and a second major surface on opposite side from the first major surface;
a base plate supporting the ceramic dielectric substrate and including a gas feed channel; and
a first porous part provided at a position between the base plate and the first major surface of the ceramic dielectric substrate, the position being opposed to the gas feed channel,
the ceramic dielectric substrate including a first hole part located between the first major surface and the first porous part,
the first porous part including:
a porous section including a plurality of pores; and
a first compact section being more compact than the porous section, and
the porous section including a plurality of sparse portions including a plurality of pores including a first pore and a second pore, and a dense portion having a higher density than the sparse portion,
each of the plurality of sparse portions extending in a first direction,
the dense portion is located between the plurality of sparse portions, and
in the second direction, dimension of the plurality of pores provided in each of the plurality of sparse portions is smaller than dimension of the dense portion.
|