Aluminum oxide selective etch

摘要

Methods of selectively etching aluminum oxide from the surface of a patterned substrate are described. The etch selectively removes aluminum oxide relative to other metal oxides and silicon-containing films such as silicon, polysilicon, silicon oxide, silicon germanium and/or silicon nitride. The methods include exposing aluminum oxide to plasma effluents formed in a remote plasma from a chlorine-containing precursor and a hydrocarbon. A remote plasma is used to excite the precursors and a local plasma is used to further excite the plasma effluents and accelerate ions toward the patterned substrate.

主权项

1. A method of etching aluminum oxide, the method comprising:
placing a patterned substrate in a substrate processing region of a substrate processing chamber, wherein the patterned substrate comprises an exposed aluminum oxide portion; flowing a chlorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region; flowing a hydrogen-and-carbon-containing precursor into the remote plasma region; forming a remote plasma in the remote plasma region from the chlorine-containing precursor and the hydrogen-and-carbon-containing precursor to produce plasma effluents; flowing the plasma effluents into the substrate processing region through through-holes in a showerhead, wherein the showerhead is disposed between the remote plasma region and the substrate processing chamber; forming a bias plasma in the substrate processing region to further excite the plasma effluents; and etching the exposed aluminum oxide portion from the patterned substrate, wherein a temperature of the patterned substrate is below 130° C. during the operation of etching the exposed aluminum oxide portion.