Electrostatic chuck device and sleeve for electrostatic chuck device
An electrostatic chuck device containing a substrate, a stack stacked on an upper surface of the substrate in the thickness direction, and a ceramic layer stacked on an upper surface of the stack in the thickness direction. A sleeve formed from an insulating material is inserted into a through-hole that penetrates through the substrate and the stack in the thickness direction. The upper surface of the sleeve in the thickness direction has a two-level structure including a first upper surface positioned on the same plane as an upper surface of the substrate in the thickness direction, and a second upper surface positioned above the first upper surface in the thickness direction of the sleeve and disposed proximate to the ceramic layer. In a plan view, an edge portion of the stack is disposed on top of the first upper surface.
1. An electrostatic chuck device comprising:
a substrate,
a stack containing at least an internal electrode stacked on top of the substrate,
a ceramic layer stacked on an upper surface of the stack in a thickness direction,
a through-hole penetrating through the substrate and the stack in the thickness direction,
a sleeve formed from an insulating material and inserted in the through-hole, an upper surface of the sleeve in the thickness direction including a two-level structure having a first upper surface positioned coplanar with an upper surface of the substrate in the thickness direction, and a second upper surface positioned above the first upper surface in the thickness direction and disposed proximate to the ceramic layer, an edge portion of the stack in a plan view being disposed on top of the first upper surface,
wherein a space between an outside surface of the edge portion and an outside surface between the first upper surface and the second upper surface is either (i) filled with a filler or (ii) left as a void.
2. The electrostatic chuck device according to claim 1 , wherein the ceramic layer has a base layer, and a surface layer having unevenness formed on an upper surface of the base layer in a thickness direction.
3. The electrostatic chuck device according to claim 1 , wherein the edge portion defines a length in a horizontal direction between 10% and 90% of a distance from the outside surface between the first upper surface and the second upper surface to an outside edge of the first upper surface.
4. The electrostatic chuck device according to claim 1 , wherein the edge portion defines a length in a horizontal direction between 35% and 75% of a distance from the outside surface between the first upper surface and the second upper surface to an outside edge of the first upper surface.