Selective titanium nitride removal

摘要

Methods are described herein for selectively etching titanium nitride relative to dielectric films, which may include, for example, alternative metals and metal oxides lacking in titanium and/or silicon-containing films (e.g. silicon oxide, silicon carbon nitride and low-K dielectric films). The methods include a remote plasma etch formed from a chlorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride. The plasma effluents react with exposed surfaces and selectively remove titanium nitride while very slowly removing the other exposed materials. The substrate processing region may also contain a plasma to facilitate breaking through any titanium oxide layer present on the titanium nitride. The plasma in the substrate processing region may be gently biased relative to the substrate to enhance removal rate of the titanium oxide layer.

主权项

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 titanium nitride region and an exposed second material region, the method comprising:
flowing a chlorine-containing precursor into a remote plasma region fluidly coupled to the substrate processing region while forming a remote plasma in the remote plasma region using a remote RF power to produce plasma effluents; forming a local plasma in the substrate processing region during the operation of forming the remote plasma in the plasma region; and etching exposed titanium nitride from the substrate by flowing the plasma effluents into the substrate processing region through through-holes in a showerhead, wherein the showerhead separates the substrate processing region from the remote plasma region.