Sputter Etching With Argon/Fluorinated Gas Mixture
Original Publication Date: 1987-Dec-01
Included in the Prior Art Database: 2005-Feb-02
A method is reported for extending the range of facet angles that can be produced with argon sputter etching. Sputter etching vertical oxide steps with pure argon will facet the steps. Usually the facet angle produced is in the 45o - 55o range and has little dependence on etch conditions. The rate of etch has a strong dependence on the power used. Through the addition of small quantities (less than 5%) of fluorinated gas to the argon gas normally used in a sputter etching process, vertical oxide and nitride steps can be faceted to approximately 70o when the gas flow rate is optimized. Too little fluorinated gas produces angles similar to those produced with pure argon. Too much fluorinated gas results in insufficient facetting.