Control of etch rate ratio of sio2/photoresist for quartz planarization etch back process

摘要

A method of controlling the etch rate ratio of SiO₂ photoresist (PR) in a quartz planarization etch back process involves etching with a gaseous mixture containing CF₄ and either CHF₃ or C_xF_y with x 1 or O₂. The preferred SiO₂/PR ratio of 1.2 = 0.1 is obtained by either adding CHF₃ to decrease the etch rate of the PR or by adding O₂ to increase the etch rate of the PR.