Prevention of In-Vacuo Resist Outgassing
Original Publication Date: 1983-Nov-01
Included in the Prior Art Database: 2005-Feb-07
This article describes a method for reducing resist "outgassing" which produces skirting effects in lift-off processes, by forming a gas impermeable lining on the exterior of the resist prior to metal deposition. Resist outgassing during any processing in vacuum (especially if the wafers are at an elevated temperature) can cause concentrated scattering of evaporated or plasma species. The result of scattered metal during metal deposition is a "skirt" which is a thin layer of metal extending over areas which are supposed to be free of metal. Furthermore, if resist outgassing takes place during plasma etch, the etchant --plasma species--can react with outgassing molecules and prevent the plasma from etching with the same efficiency in small areas or near resist edges.