Condition selectable backside gas

A method of semiconductor processing, the method comprising:

• flowing a first backside gas at a first flow rate through a substrate support in a processing region of a semiconductor processing chamber while processing a semiconductor substrate seated on the substrate support;
• removing the semiconductor substrate from the semiconductor processing chamber;
• performing a plasma cleaning operation within the processing region of the semiconductor processing chamber;
• and
• flowing a second backside gas through the substrate support at a second flow rate while performing the plasma cleaning operation, wherein at least a portion of the second backside gas flows into the processing region through accesses in the substrate support.

A method of semiconductor processing, the method comprising:

• performing a process on a semiconductor substrate, the semiconductor substrate seated on a substrate support within a processing region of a semiconductor processing chamber, wherein the process is performed while maintaining the substrate support at a temperature below or about 0° C.;
• raising the semiconductor substrate from the substrate support;
• forming a plasma of a post-treatment precursor within the processing region of the semiconductor processing chamber;
• flowing a non-reactive backside gas through the substrate support and between the semiconductor substrate and the substrate support;
• and
• increasing a temperature of the semiconductor substrate.