Deep UV Photoresists I. Meldrum's Diazo Sensitizer

The design, synthesis, and evaluation of a new resist formulation tailored for use in the deep UV (254 nm) is described. The resist is based on use of 2, 2-dimethyl-4, 6-dioxo-5-diazo-l, 3-dioxolane (5- diazo-Meldrum‘s acid) and derivatives thereof as a sensitizer for cresol formaldehyde novolac resin. The new class of sensitizers provides an intense bleachable absorbance at 254 nm and couples sensitivity with plasma etch resistance. The resist exhibits remarkable dissolution kinetics which provide for high resolution imaging devoid of standing wave phenomena. A series of experiments designed to provide understanding of the dissolution kinetics are described. Copyright © 1981 by The Institute of Electrical and Electronics Engineers, Inc.