Electrostatic chuck
An insulating substrate has a sample holding surface. A support is bonded to the insulating substrate. A first through-hole in the insulating substrate and a second through-hole in the support are continuous with each other to serve as a gas inlet. A porous member is located in the second through-hole. The second through-hole has, at its opening adjacent to the insulating substrate (opening adjacent to the substrate), a larger diameter than the first through-hole. The opening of the second through-hole and an electrostatic attraction electrode are at different positions in a direction parallel to the sample holding surface. The electrostatic attraction electrode and the second through-hole avoid overlapping each other as viewed from above.
1. An electrostatic chuck, comprising:
a substrate comprising:
a first surface for holding a sample, the first surface comprising a first opening;
a second surface opposite to the first surface, the second surface comprising a second opening; and
a first through-hole from the first opening to the second opening, the first through-hole has a first diameter;
an electrode located inside the substrate, and comprising a first part and a second part next to the first part in a cross-sectional view;
a support comprising:
a third surface comprising a third opening;
a fourth surface opposite to the third surface, the fourth surface comprising a fourth opening; and
a second through-hole from the third opening to the fourth opening, the second through-hole has a second diameter at the third opening being larger than the first diameter,
wherein the second through-hole is between the first part and the second part in the cross-sectional view; and
a porous member is located in the second through-hole.
2. The electrostatic chuck according to claim 1 , further comprising:
a bond material located between the second surface and the third surface.
3. The electrostatic chuck according to claim 2 ,
wherein an upper end of the porous member is located above an upper end of the bonding material.
4. The electrostatic chuck according to claim 1 ,
wherein the second diameter at the third opening is larger than the second diameter at the fourth opening.
5. The electrostatic chuck according to claim 1 , further comprising:
a first area located between the support and the porous member in the cross-sectional view,
wherein the first area is gap.
6. The electrostatic chuck according to claim 1 ,
wherein the porous member is in contact with the support.
7. The electrostatic chuck according to claim 1 , further comprising:
a tubular member located in the second through-hole and surrounding the porous member.
8. The electrostatic chuck according to claim 1 ,
wherein the substrate has a recess on the second surface, and the porous member is fixed in the recess.
9. The electrostatic chuck according to claim 8 , further comprising:
a tubular member located in the second through-hole and surrounding the porous member,
wherein the tubular member is located in the recess.
10. The electrostatic chuck according to claim 9 ,
wherein the recess has a wall, and
the tubular member is contact with the wall.
11. The electrostatic chuck according to claim 8 , further comprising:
a bond material located between the second surface and the third surface,
wherein the porous member is fixed in the recess with an adhesive, and
a thermal conductivity of the adhesive is higher than a thermal conductivity of the substrate.
12. The electrostatic chuck according to claim 8 , wherein
the recess is between the first part and the second part in the cross-sectional view.
13. The electrostatic chuck according to claim 8 ,
wherein the recess has a wall, and the electrostatic chuck comprises a plasma-resistant member on the wall.
14. An electrostatic chuck, comprising:
a substrate comprising:
a first surface for holding a sample, the first surface comprising a first opening;
a second surface opposite to the first surface, the second surface comprising a second opening; and
a first through-hole from the first opening to the second opening, the first through-hole has a first diameter;
an electrode located inside the substrate, and comprising a first part and a second part next to the first part in a cross-sectional view;
a support comprising:
a third surface comprising a third opening;
a fourth surface opposite to the third surface, the fourth surface comprising a fourth opening; and
a second through-hole from the third opening to the fourth opening, the second through-hole has a second diameter at the third opening being larger than the first diameter,
a porous member located in the second through-hole,
wherein the porous member is between the first part and the second part in the cross-sectional view.
15. An electrostatic chuck, comprising:
a substrate having:
a first surface for holding a sample,
a second surface opposite to the first surface; and
a first through-hole from the first surface to the second surface; and
an electrode between the first and second surfaces, and comprising a first part and a second part next to the first part in a cross-sectional view;
a support comprising:
a third surface;
a fourth surface opposite to the third surface; and
a second through-hole from the third surface to the fourth surface, below the first through hole, the second through-hole including a porous member.
16. The electrostatic chuck of claim 15 , wherein the porous member is located between the first part and the second part in the cross-sectional view.
17. The electrostatic chuck of claim 15 , wherein the first through-hole has a first diameter, and the second through-hole has a second diameter, which is different from the first diameter.
18. The electrostatic chuck of claim 17 , wherein the first diameter changes between the first surface and the second surface.
19. The electrostatic chuck of claim 17 , wherein the second diameter changes between the third surface and the fourth surface.
20. The electrostatic chuck of claim 15 , further comprising a bond material located between the second surface and the third surface.