Wafer processing hardware for epitaxial deposition with reduced backside deposition and defects

1. An apparatus for supporting a substrate, comprising:

a substrate support ring having a substrate holder structure attached thereto for supporting the substrate in a position for processing, the substrate holder structure configured to support the substrate along an edge defined by the backside of the substrate and a sidewall of the substrate or along a plurality of discrete points on or proximate to the edge; and

a spacer ring for positioning the substrate support ring above a susceptor plate to define a substrate gap region between the susceptor plate and the backside of the substrate, the spacer ring comprising a plurality of openings formed therethrough that facilitate passage of a gas into and out of the substrate gap region.

2. The apparatus of claim 1 , wherein the substrate holder structure comprises an angled ledge configured to support the substrate along the edge.

3. The apparatus of claim 1 , wherein the substrate holder structure comprises a plurality of tabs configured to support the substrate along a plurality of discrete points on or proximate the edge.

4. The apparatus of claim 3 , wherein the tabs are angled and configured to support the substrate along a plurality of discrete points on the edge.

5. The apparatus of claim 1 , wherein the substrate holder structure comprises a plurality of bumps configured to support the substrate along a plurality of discrete points proximate the edge.

6. The apparatus of claim 1 , wherein the substrate support ring, substrate holder structure, and spacer ring comprise one or more of silicon carbide, quartz, graphite, silicon nitride, or aluminum nitride.

7. The apparatus of claim 1 , wherein the thickness of the walls of the substrate support ring are between about 0.002 inches to about 0.3 inches.

8. The apparatus of claim 1 , wherein the spacer ring is sized to define a substrate gap region of between 0.1 inches to about 1.0 inches.

9. The apparatus of claim 1 , wherein the plurality of openings in the spacer ring define an open area that is between about 5 to about 60 percent open.

10. The apparatus of claim 1 , wherein the spacer ring and the plurality of openings formed therethrough are configured to allow auto-dopants to escape from the substrate gap region while restricting deposition on the backside of the substrate due to process gases introduced to a top side of the substrate during processing.

11. An apparatus for depositing an epitaxial layer on a substrate, comprising:

a processing chamber;

a susceptor plate within the processing chamber;

a substrate support ring having a substrate holder structure attached thereto for supporting the substrate in a position for processing, the substrate holder structure configured to support the substrate along an edge defined by the backside of the substrate and a sidewall of the substrate or along a plurality of discrete points proximate the edge;

a spacer ring to position the substrate support ring above the susceptor plate and define a substrate gap region between the susceptor plate and the backside of the substrate when the substrate is supported by the substrate holder structure, wherein the spacer ring comprises a plurality of openings formed therethrough that facilitate passage of a gas into and out of the substrate gap region;

an upper injection manifold for providing reactant gases onto the front side of the substrate;

a lower injection manifold for providing an inert gas into the processing chamber proximate to the substrate gap region; and

a lower exhaust port for removing exhaust gases containing autodopants from the processing chamber.

12. The apparatus of claim 11 , wherein the substrate holder structure comprises an angled ledge configured to support the substrate along the edge.

13. The apparatus of claim 11 , wherein the substrate holder structure comprises a plurality of tabs configured to support the substrate along a plurality of discrete points on or proximate the edge.

14. The apparatus of claim 13 , wherein the tabs are angled and configured to support the substrate along a plurality of discrete points on the edge.

15. The apparatus of claim 11 , wherein the substrate holder structure comprises a plurality of bumps configured to support the substrate along a plurality of discrete points proximate the edge.

16. The apparatus of claim 11 , wherein the spacer ring is sized to define a substrate gap region of between 0.1 inches to about 1.0 inches.

17. The apparatus of claim 11 , wherein the plurality of openings in the spacer ring define an open area that is between about 5 to about 60 percent open.

18. The apparatus of claim 11 , further comprising:

an upper exhaust port for removing reacted gases and residual reactant gases from a region over the front side of the substrate.

19. The apparatus of claim 11 , wherein the spacer ring and the susceptor plate are integrally formed.

20. An apparatus for supporting a substrate, comprising:

a substrate support ring having a substrate holder structure attached thereto to support the substrate in a position for processing, the substrate holder structure configured to support the substrate along an edge defined by the backside of the substrate and a sidewall of the substrate or along a plurality of discrete points on or proximate to the edge such that the substrate is supported only by the substrate holder structure; and

a spacer ring, separable from the substrate support ring, disposed under the substrate support ring and configured to be disposed atop a susceptor plate to position the substrate support ring above the susceptor plate to define a substrate gap region between the susceptor plate and the backside of the substrate, the spacer ring comprising a plurality of openings formed therethrough that facilitate passage of a gas into and out of the substrate gap region.