Substrate processing system having susceptorless substrate support with enhanced substrate heating control
Methods and apparatus for processing substrates are provided herein. In some embodiments, an apparatus includes a process kit, the process kit comprising a first ring to support a substrate proximate a peripheral edge of the substrate; a second ring disposed about the first ring; and a path formed between the first and second rings that allows the first ring to rotate with respect to the second ring, wherein the path substantially prevents light from travelling between a first volume disposed below the first and second rings and a second volume disposed above the first and second rings.
1. An apparatus for processing a substrate, comprising:
a processing chamber having a substrate support comprising a first ring to support a substrate proximate a peripheral edge of the substrate, a base disposed below the first ring, and one or more and a plurality of support members extending from the base in contact with and supporting the first ring above the base;
a second ring disposed about the substrate support, the second ring having an inner lip extending radially inward from an inner surface of the second ring;
a lamphead to provide energy to a substrate when disposed on the substrate support, wherein the base is formed of material that is substantially transparent to wavelengths of light provided by the lamphead;
a temperature sensor opposing the lamphead to measure energy radiated from the substrate; and
a path formed between the first and second rings that allows the first ring to rotate with respect to the second ring, wherein the path substantially prevents light from travelling between a first volume disposed below the first and second rings and a second volume disposed above the first and second rings.
2. The apparatus of claim 1 , wherein the path is formed by an overlap between a substrate-opposing end of the first ring and the inner lip.
3. The apparatus of claim 1 , wherein the path is formed between at least one first protrusion extending upward from a substrate-opposing end of the first ring and at least one second protrusion extending downward from the inner lip of the second ring.
4. The apparatus of claim 1 , wherein the first ring is disposed directly on the plurality of support members.
5. The apparatus of claim 4 , wherein the first ring includes at least one first annular rib extending downward from a bottom surface of the first ring that is configured to limit deformation of the first ring during substrate processing.
6. The apparatus of claim 5 , wherein the at least one first rib is disposed proximate the plurality of support members.
7. The apparatus of claim 1 , wherein the plurality of support members have a first cross section proximate the base that is wider than a second cross section proximate the first ring.
8. The apparatus of claim 1 , wherein the apparatus further comprises:
a cylindrical body disposed below the second ring; and
a third path formed between the cylindrical body and the second ring, wherein the third path reduces process gas flow between the second volume and a back side of a substrate when disposed on the first ring.
9. The apparatus of claim 8 , wherein the cylindrical body extends upward from a peripheral edge of the base to form the third path between the cylindrical body and the second ring.
10. The apparatus of claim 1 , wherein the peripheral edge of the base extends below the second ring.
11. The apparatus of claim 1 , wherein the lamphead provides a first energy that transmits through a substrate when disposed on the substrate support and a second energy that is absorbed by a substrate when disposed on the substrate support.
12. The apparatus of claim 11 , wherein the temperature sensor is configured to measure the second energy and not the first energy and wherein the base is transmissive to the first and second energies.