Highly selective doped oxide removal method

摘要

A method of etching doped silicon oxide on patterned heterogeneous structures is described and includes a gas phase etch using partial remote plasma excitation. The remote plasma excites a fluorine-containing precursor and the plasma effluents created are flowed into a substrate processing region. A hydrogen-containing precursor, e.g. water, is concurrently flowed into the substrate processing region without plasma excitation. The plasma effluents are combined with the unexcited hydrogen-containing precursor in the substrate processing region where the combination reacts with the doped silicon oxide. The plasmas effluents react with the patterned heterogeneous structures to selectively remove doped silicon oxide.

主权项

1. A method of etching a patterned substrate, the method comprising:
transferring the patterned substrate into a substrate processing region of a substrate processing chamber, wherein the patterned substrate has exposed doped silicon oxide and exposed undoped silicon oxide; producing plasma effluents by flowing a fluorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a remote plasma in the remote plasma region; flowing water vapor into the substrate processing region without first passing the water vapor through any remote plasma; and etching the exposed doped silicon oxide faster than the exposed undoped silicon oxide, wherein the exposed doped silicon oxide is one of boron-doped silicate glass, phosphorus-doped silicate glass or boron-and-phosphorus-doped silicate glass.