Lithographic process for high-resolution metal lift-off

An improved single layer lithographic metal lift off process which relies on formation of an inhibition layer at the top of the resist film by a simple treatment with an aqueous TMAH solution is introduced. The improvements that lead to an increase in the amount of overhang in the process are a flood exposure step prior to the post exposure bake and the use of a solvent containing TMAH solution of the soak. Both improvements can be used to enhance the amount of overhand above the defined space to arrive at desirable result for a single layer metal lift-off process. A basic chemical mechanism responsible for the formation of the overhang is proposed. The new lithographic processes described are capable of providing resist patterns with resolution better than 0.5 micrometers isolated spaces with a 0.54 NA i-line stepper in a facile single layer process.