Fabrication method for controlled via hole process

摘要

A method for forming via holes having a rounded sidewall profile includes exposing a layer or organic positive photoresist to a formic gas plasma while the surface of the photoresist layer is bombarded with ions and electrons in a high voltage biased environment in which the photoresist layer is capacitively coupled. The photoresist layer may be exposed to UV light either before or after the formic gas plasma step.