Patent ID: 9324576
Filing Date: 2016-04-26
CPC Classification: H01L

Claim Text:
1. A method of etching a patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned substrate has an exposed oxygen-and-silicon-containing region and an exposed silicon-containing region which contains less oxygen than the oxygen-and-silicon-containing region, the method comprising: flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a plasma in the remote plasma region to produce plasma effluents; neutralizing charged species generated in the remote plasma prior to flowing plasma effluents into the substrate processing region such that the plasma effluents comprise less than 10 percent charged species; etching the exposed silicon-containing region faster than the exposed oxygen-and-silicon-containing region by flowing the plasma effluents into the substrate processing region wherein the etching is performed while maintaining a partial pressure of the fluorine-containing precursor below about 100 mTorr; and wherein the exposed silicon-containing region consists essentially of silicon and the etching is generally uniform.