Substrate support for substrate backside contamination control

1. A substrate support, comprising:

a first aluminum plate for supporting a substrate, the first aluminum plate having a plurality of heating elements embedded therein to provide a plurality of heating zones;

a second aluminum plate disposed beneath and supporting the first aluminum plate;

a third aluminum plate disposed beneath and supporting the second aluminum plate;

a non-metallic ring disposed atop the first aluminum plate, wherein the non-metallic ring is fabricated from aluminum nitride (AlN) or aluminum oxide (Al 2 O 3 );

a plurality of spacers having an upper portion disposed above a surface of the first aluminum plate, wherein the non-metallic ring and the plurality of spacers support the substrate above the first aluminum plate; and

a non-metallic disk disposed proximate a center of the first aluminum plate, the non-metallic disk having an upper portion disposed above a top surface of the first aluminum plate and a shaft coupled to a bottom of the non-metallic disk, wherein the non-metallic disk, non-metallic ring, and the plurality of spacers support the substrate above the first aluminum plate, and wherein the shaft is disposed within a through hole formed in the first aluminum late.

2. The substrate support of claim 1 , wherein the plurality of spacers are at least partially recessed into a top surface of the first aluminum plate.

3. The substrate support of claim 1 , wherein the plurality of spacers have a substantially spherical shape.

4. The substrate support of claim 1 , wherein the non-metallic ring and the plurality of spacers support the substrate about 0.002 to about 0.010 inches above the first aluminum plate.

5. The substrate support of claim 1 , wherein the plurality of spacers are fabricated from sapphire.

6. The substrate support of claim 1 , wherein the first aluminum plate further comprises a plurality of channels formed in a bottom surface of the first aluminum plate, wherein the heating elements are disposed within the plurality of channels, and wherein the heating elements are secured in the plurality of channels by the second aluminum plate.

7. The substrate support of claim 1 , further comprising:

a plurality of pins, each having a first end disposed in a feature of the first aluminum plate and a second end extending beyond a top surface of the first aluminum plate and configured to interface with a feature formed in a bottom surface of the non-metallic ring to maintain the non-metallic ring in a desired position.

8. The substrate support of claim 1 , wherein the non-metallic disk is at least partially recessed into the first aluminum plate.

9. The substrate support of claim 1 , wherein the non-metallic disk is fabricated from aluminum nitride (AlN) or aluminum oxide (Al 2 O 3 ).

10. The substrate support of claim 1 , wherein the plurality of heating elements comprise:

a first heater element configured to provide heat to an inner portion of the first aluminum plate; and

a second heater element configured to provide heat to an outer portion of the first aluminum plate.

11. The substrate support of claim 10 , wherein a portion of the first heater element comprises two or more curved sections disposed proximate a center of the first aluminum plate to provide heat to an area proximate the center of the first aluminum plate.

12. The substrate support of claim 1 , further comprising a support shaft disposed beneath the third aluminum plate to support the third aluminum plate, the support shaft comprising:

a body having a hollow portion formed within the body; and

one or more conduits formed in the body, wherein each of the one or more conduits are configured to provide a gas or apply a vacuum to an area above the first aluminum plate.

13. The substrate support of claim 12 , wherein the support shaft further comprises:

a thermocouple to provide a temperature of the first aluminum plate, the thermocouple disposed within the hollow portion of the support shaft; and

an aluminum tube surrounding the thermocouple.

14. The substrate support of claim 12 , wherein the support shaft is fabricated from aluminum.

15. A substrate support, comprising:

a first aluminum plate for supporting a substrate, the first aluminum plate having a plurality of heating elements embedded therein to provide a plurality of heating zones;

a second aluminum plate disposed beneath and supporting the first aluminum plate;

a third aluminum plate disposed beneath and supporting the second aluminum plate;

a non-metallic ring disposed atop the first aluminum plate;

a plurality of spacers having an upper portion disposed above a surface of the first aluminum plate, wherein the non-metallic ring and the plurality of spacers support the substrate above the first aluminum plate;

a purge ring disposed about a periphery of the first aluminum plate; and

a plurality of metal clips, wherein each of the plurality of metal clips comprise a first end coupled to the purge ring, a second end coupled to the first aluminum plate and a curved section coupling the first end to the second end, and wherein the plurality of metal clips electrically couple the purge ring to the first aluminum plate.

16. The substrate support of claim 15 , wherein the first end and second end of each of the plurality of metal clips comprise a through hole configured to allow the first end and second end to be coupled to the first aluminum plate and purge ring via one or more fasteners.

17. A process chamber, comprising:

a chamber body having an inner volume;

a substrate support disposed within the inner volume of the chamber body, the substrate support comprising:

a first aluminum plate for supporting a substrate, the first aluminum plate having a plurality of heating elements embedded therein to provide a plurality of heating zones;

a second aluminum plate disposed beneath and supporting the first aluminum plate;

a third aluminum plate disposed beneath and supporting the second aluminum plate;

a non-metallic ring disposed atop the first aluminum plate;

a plurality of spacers having an upper portion disposed above a surface of the first aluminum plate, wherein the non-metallic ring and the plurality of spacers support the substrate above the first aluminum plate;

a purge ring disposed about a periphery of the first aluminum plate; and

a plurality of metal strips, wherein each of the plurality of metal strips comprise a first end coupled to the purge ring, a second end coupled to the first aluminum plate and a curved section coupling the first end to the second end, and wherein the plurality of metal strips electrically couple the purge ring to the first aluminum plate.

18. The substrate support of claim 1 , wherein the non-metallic disk further comprises:

a through hole extending through the shaft and the non-metallic disk to prevent gas from being trapped between the non-metallic disk and the first aluminum plate.