Method and apparatus to inhibit obstruction of optical transmission through semiconductor etch process chamber viewport

摘要

A method and apparatus are described for inhibiting visual obstruction of the window of a semiconductor etch process chamber by deposition of each byproducts thereon by selectively heating the window surfaces adjacent one edge of the window to thereby form a cool region on the window surfaces adjacent the opposite edge of the window whereby the center of the window will remain substantially clear of such depositions. The apparatus for carrying out the method of the invention comprises a first heat transmitting structure disposed on one surface of an optically transparent window adjacent one edge, and a second heat transmitting structure disposed on the opposite surface of the optically transparent window adjacent the same edge to thereby provide even heating of both surfaces of the window adjacent the one edge, thereby creating a cooler zone on the window surfaces adjacent the opposite edge of the window.