PECVD process

A semiconductor processing device, comprising:

• a first chamber having an internal volume defined by a side wall, a floor, and a lid;
• a first gas distributor having a plurality of gas flow openings formed therethrough;
• and
• a first substrate support disposed in the internal volume of the chamber, the first substrate support comprising:
• a first heating element disposed in the first substrate support;
• a second heating element disposed in the first substrate support beneath the first heating element and extending radially outward beyond the first heating element;
• and
• a first thermocouple disposed in the first substrate support beneath the second heating element;
• and
• a second chamber having an internal volume defined by a side wall, a floor, and a lid;
• a second gas distributor having a plurality of gas flow openings formed therethrough;
• and
• a second substrate support disposed in the internal volume of the chamber, the second substrate support comprising:
• a third heating element disposed in the second substrate support;
• a fourth heating element disposed in the second substrate support beneath the third heating element and extending radially outward beyond the third heating element;
• and
• a second thermocouple disposed in the second substrate support beneath the fourth heating element.

A semiconductor processing device, comprising:

• a chamber having an internal volume defined by a side wall, a floor, and a lid;
• a gas distributor having a plurality of gas flow openings formed therethrough, the gas flow openings being more densely distributed at a center of the gas distributor and less densely distributed at an edge of the gas distributor;
• a substrate support disposed in the internal volume of the chamber;
• and
• an electrode coupled to the substrate support, the electrode coupled to a tuning circuit, wherein the tuning circuit comprises a variable capacitor.