Improved Etch Uniformity by Ultraviolet Hardening of the Photoresist
Original Publication Date: 1985-Nov-01
Included in the Prior Art Database: 2005-Feb-19
By exposing positive photoresist to ultraviolet (UV) radiation, the resist becomes less reactive to etchants used in reactive ion etching (RIE). This slower reactivity results in a more uniform rate of film etching over large areas, especially when low etchant gas flow rate and low pressure of etch gas (<30 millitorr) isused in a planar RIE system. This UV hardening process minimizes the removal of the photoresist in the downstream direction of reactive gas flow, and results in more uniform etching of the film.