Substrate heater and fabrication method for the same

1. A substrate heater comprising:

a plate-shaped ceramic base having a first side defining a convex heating surface on at least a portion of which a substrate is placed;

a resistance-heating element embedded in the ceramic base; and

a tubular member joined to a central portion on an opposed second side of the ceramic base;

wherein a height of the heating surface decreases from a central portion of the heating surface to a peripheral portion thereof.

2. The substrate heater of claim 1 , wherein the ceramic base comprises a planar electrode embedded therein between the heating surface and the resistance-heating element.

3. The substrate heater of claim 2 , wherein the planar electrode comprises one of a mesh-shaped electrode of a metal bulk body and a plate-shaped electrode with open holes.

4. The substrate heater of claim 1 , further comprising a vacuum chuck hole on the heating surface configured to adsorb and fix the substrate on the heating surface.

5. The substrate heater of claim 1 , wherein a difference ΔH between a height Hc at the central portion of the heating surface and a height He at the peripheral portion of the heating surface is 50 μm or less.

6. The substrate heater of claim 5 , wherein the difference ΔH is at least 10 μm.

7. The substrate heater of claim 1 , wherein the ceramic base comprises a main component including one of a non-oxide ceramic and a composite of at least two non-oxide ceramics selected from the group consisting of aluminum nitride, silicon nitride, silicon carbide and sialon.

8. The substrate heater of claim 1 , wherein a main component of the tubular member is identical to that of the ceramic base.

9. A method for fabricating a substrate heater, comprising the steps of:

embedding a resistance-heating element in a plate-shaped ceramic base;

grinding a first surface of the ceramic base to form a convex heating surface having a height that decreases from a central portion of the heating surface to a peripheral portion thereof; and

joining a tubular member to a central portion of an opposed second surface of the ceramic base.

10. The method of claim 9 , wherein the embedding step further comprises embedding a planar electrode in the ceramic base.

11. The method of claim 9 , wherein the grinding step further comprises the step of adjusting a difference ΔH between a height Hc at the central portion of the heating surface and a height He at the peripheral portion of the heating surface to be 50 μm or less.

12. The method of claim 11 , wherein the difference ΔH is adjusted to at least 10 μm.