Resolution Enhancement in Dry Film Photoresist
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
A procedure is disclosed whereby the intrinsic resolution of a dry film photoresist can be doubled via a dual apply/expose process. Commercially available dry film photoresists will not suffice for applications requiring high aspect ratio (resist thickness to lines/ spaces resolved) resist performance. In comparison to the conventional process flow, the technique outlined below (see figures) enables production of 1.0-mil lines/spaces in a 2.0-mil thick photoresist: 1) Apply photoresist to substrate. (Image Omitted) 2) Register to artwork and expose. 3) Apply second resist layer to imaged layer. 4) Re-register to artwork and expose. 5) Develop.