Fabrication of microlens arrays by direct electron beam exposure of photoresist

Abstract
A novel process has been developed for the fabrication of dry-etch masks capable of defining diffractive structures in quartz. Shipley S1805 and UVIII photoresists have been patterned by electron beam lithography to exploit the high dry-etch resistance of photoresist and the attributes of electron beam lithography. The yield, linewidth fidelity, uniformity, verticality and resolution of the diffractive structures demonstrate that the process is suitable for submicron optics and avoids process repeatability problems often encountered in fabrication procedures involving metallization followed by lift-off or wet etching.