Patent ID: 9390937
Filing Date: 2016-07-12
CPC Classification: H01J,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 silicon-nitrogen-and-carbon-containing region and an exposed silicon oxide (SiO 2 ) region, the method comprising: flowing each of a fluorine-containing precursor and an oxygen-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a plasma in the plasma region to produce plasma effluents, wherein flowing each of the fluorine-containing precursor and the oxygen-containing precursor into the remote plasma region comprises maintaining an O:F atomic flow ratio above or about 2:1 and below or about 10:1; and etching the exposed silicon-nitrogen-and-carbon-containing region by flowing the plasma effluents into the substrate processing region through through-holes in a showerhead, wherein the plasma effluents are essentially devoid of hydrogen, and wherein the selectivity of the etching operation defined as the etching rate ratio of the exposed silicon-nitrogen-and-carbon-containing region to the exposed silicon oxide region, is greater than or about 150:1.