Multilayer Resist for Releasing Hardened Resist
Original Publication Date: 1986-Nov-01
Included in the Prior Art Database: 2005-Mar-09
When fabricating semiconductors, an alternative method for removing hardened photoresist which does not utilize plasma ashing techniques involves the use of a photoresist release film. Photoresists frequently require ultraviolet (UV) light hardening and a bake cycle in order to withstand subsequent high temperature plasma processing. Once hardened, the only way to remove a photoresist is by plasma ashing in oxygen. However, this is not desirable when the underlying material is also etched in a plasma ash. Fig. 1 shows a cross-section of a semiconductor structure 10 with two levels of metal, i.e., M1 metal lines 11 and a second level metal 12, with a polyimide insulator 13 therebetween. Atop the second level metal 12 is a photoresist release film 14, poly(dimethlyglutarimide) or PMGI, and another photoresist layer 15.