The Mechanism of Single-Step Liftoff with Chlorobenzene in a Diazo-Type Resist

The mechanism of the chlorobenzene single-step liftoff process is defined. The chlorobenzene penetrates to some depth into the resist film during the soaking cycle, extracting residual casting solvent and low-molecular-weight resin species. The chlorobenzene is subsequently removed by a rinse cycle. The penetrated layer of resist develops at a slower rate than the underlying bulk resist, producing the liftoff structure.