Low-Temperature Etching of 0.2 µm Al Patterns Using a SiO2 Mask

Abstract

The effects of etching temperature and gases on the microloading and critical dimension (CD) shifts are investigated for Al etching using a SiO2 mask. Al etching with a SiO2 mask using Cl2 gas at low temperature achieved etching resistance against the mask, selective Al etching of underlying SiO2, suppression of microloading, CD shift, and after-corrosion. Al etching of 0.2 µm was successfully achieved by using the SiO2 mask and Cl2 gas chemistry at low temperature.