Technique for Reversal Processing of Sulfone-Sensitized Resists
Original Publication Date: 1984-Feb-01
Included in the Prior Art Database: 2005-Feb-02
A technique for reversing images in sulfone-sensitized novolak resists (a positive-working E-beam resist) was developed from an attempt to increase the induction time of unexposed regions. Four wafers were processed up to the development step. The development was interrupted at various points during the development cycle for different wafers. In each case, the sample was then rinsed, blown dry, and then baked for one minute on a 105ŒC hot plate. After the bakes, the wafers were again immersed in the developer. 1. Interrupted at 200% beyond exposed endpoint: The induction was increased dramatically T so the unexposed regions did not dissolve any further even after an additional 400%. 2. Interrupted after 2^ peaks of the exposed endpoint trace (about 7000 ^ of resist remaining): No differences were observed.