Temperature controlled anode for plasma dry etchers for etching semiconductor

Claim 1

A plasma dry etcher including an anode plate, wherein the anode plate is adapted to support a semiconductor wafer and the anode plate is mounted to the inside of an outer wall of an enclosure in a manner such that the semiconductor wafer faces the inside of the enclosure, comprising: (a) a plasma dry etch chamber forming the enclosure; (b) the anode plate having a body portion and a preferred wafer location; and (c) a cooling passage within the anode plate which extends radially outwardly from a cooling core to an extent limited to, and corresponding to, the preferred wafer location so as to preferentially cool the anode plate at the preferred wafer location, wherein the anode plate includes an outer perimeter section which, because the cooling passage extends to said preferred wafer location, has a reduced ability to thermally conduct heat from the outer perimeter, said reduced ability to thermally conduct resulting in the outer section having an elevated temperature as compared to the preferred wafer location, said construction reducing the effects of polymer deposition by minimizing hot spots on the semiconductor wafer when the outer section has said elevated temperature, said construction further permitting the wafer to be maintained at a higher average temperature. and the outer perimeter of the anode plate includes means for reducing the effects of polymer deposition which occurs during etching of a said substrate