Selective Ion Beam Etching of Al2 O 3 Films

Preferential etching of sputter‐deposited films and photoresist were investigated using a reactive ion beam etching system. Fluorohydrocarbon gases served as etching gases. When and gases were used, a problem of polymer film deposition occurred during etching of films. This problem could be overcome by using gas. Based on these results, selective etching of films and photoresist were examined using and gases. Selectivity of more than 20 could be realized with these gas mixtures. This was because the etching rate of photoresist was reduced remarkably.