Plasma reactor electrostatic chuck with cooled process ring and heated workpiece support surface

摘要

Undesirable heating of a semiconductor process ring is prevented by thermally isolating the process ring from the insulating puck of an electrostatic chuck, and providing a thermally conductive and electrically insulating thermal ring contacting both the semiconductor process ring and an underlying metal base having internal coolant flow passages.

主权项

1. A method of performing a plasma-enhanced etch process on a workpiece in a chamber of a plasma reactor, said plasma reactor comprising:
an insulating puck in said chamber and an ESC electrode in said insulating puck; a metal base layer beneath and contacting said insulating puck and having a diameter exceeding a diameter of said insulating puck, said metal base layer being coupled to a common potential; an RF plasma bias power generator having a power terminal coupled to said ESC electrode and a return terminal coupled to said common potential; said method comprising:
providing a semiconductive process ring overlying a peripheral portion of said insulating puck and a gap between said process ring and said insulating puck preventing direct thermal contact between said process ring and said insulating puck;providing a thermal ring between and in contact with said base layer and said semiconductive process ring, said thermal ring being a thermal conductor and an electrical insulator, wherein said thermal ring has a thermal conductivity in excess of about 100 Watts/m-° K;holding a workpiece on a surface of said insulating puck, introducing a process gas into said chamber and coupling plasma source power into the interior of said chamber;cooling said process ring below a first temperature by flowing coolant through coolant flow passages in said base layer; andheating said workpiece above a second temperature by applying electric power to a heating element inside said insulating puck.