Radiation shield for removing backside deposition at lift pin locations

A semiconductor processing system, comprising:

• a substrate support comprising:
• a support plate defining a plurality of lift pin locations;
• and
• a shaft coupled with the support plate;
• a shield having a body that defines a central aperture;
• a purge baffle coupled with a bottom of the shield at a position that is beyond an outer periphery of the central aperture, the purge baffle extending along at least a portion of a length of the shaft, wherein a purge gas channel is formed in a space between the purge baffle, the shield, and the substrate support;
• and
• a purge gas source coupled with a bottom of the purge baffle.

A method of semiconductor processing, comprising:

• flowing a purge gas into a processing chamber, wherein the processing chamber comprises:
• a substrate support comprising:
• a support plate that supports a semiconductor substrate, the support plate defining a plurality of lift pin locations;
• and
• a shaft coupled with the support plate;
• a shield having a body that defines a central aperture;
• a purge baffle coupled with a bottom of the shield at a position that is outside of the central aperture, the purge baffle extending along at least a portion of a length of the shaft, wherein a purge gas channel is formed in a space between the purge baffle, the shield, and the substrate support;
• and
• a purge gas source coupled with a bottom of the purge baffle;
• and
• delivering the purge gas to an underside of the semiconductor substrate at positions that are aligned with the plurality of lift pin locations via the purge gas channel.