Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Deep UV lithography is being investigated to reach the ultimate resolution of photolithography. Among the possible deep UV photoresist candidates, diazide photoresists offer several important and attractive features: aqueous-base developable, highly spectral sensitive, deep-UV selective response, are thermal stability. In the course of resist development, it was found that the combination of 3,3'-diazidobenzophenone (and its analogs or bis(m-azidophenyl)sulfone) and novolak resins gives the best performance in the deep-UV region. Described below are formulations and process conditions of these types of photoresists using 3,3'-diazidobenzophenone as an example. Formulation 9 to 25 wt % of 3,3'-diazidobenzophenone in novolak resins is dissolved in diglyme (or CELLOSOLVE* acetate containing mixed solvents or cyclohexanone).