A method of forming a patterned resist mask for etching via holes in an insulating layer.

摘要

A layer of positive resist is treated before development by exposing it to a forming gas plasma while its surface is bombarded with ions and electrons in a high voltage biased environment in which the resist layer is capacitively coupled. The resist layer is exposed to a pattern of radiation (eg ultraviolet light) defining the positions of via holes either before or after the forming gas plasma treatment. Development of the resist layer produces a mask having a pattern of via holes with rounded sidewalls.