Patent ID: 9564341
Date: 2017-02-07
CPC Classifications: H01J,H01L

Claim:
1. A method of etching a patterned substrate, the method comprising: placing the patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned substrate has an exposed silicon oxide portion and an exposed silicon nitride portion; flowing anhydrous hydrogen fluoride into the substrate processing region through a first channel comprising holes which open into the substrate processing region but not directly into the remote region; flowing a nitrogen-and-hydrogen-containing precursor into a remote region fluidly coupled to the substrate processing region through a dual-channel showerhead, wherein the nitrogen-and-hydrogen-containing precursor flows from the remote region to the substrate processing region through a second channel comprising through-holes through the dual-channel showerhead; combining the anhydrous hydrogen fluoride with the nitrogen-and-hydrogen-containing precursor within the substrate processing region, wherein the anhydrous hydrogen fluoride and the nitrogen-and-hydrogen-containing precursor do not encounter each other until after passing into the substrate processing region; dry etching the exposed silicon oxide portion, wherein a selectivity of the dry etching operation (exposed silicon oxide:exposed silicon nitride) is selectable throughout the range from 1:1 through 250:1.