High resolution x-ray mask repair

Repair of gold absorber x-ray masks with ground rules down to 250 nm is now accomplished using commercially available focused ion beam (FIB) tooling. Chief among the challenges in extending this technology to below 250 nm is that presented by the redeposition of absorber material during opaque repair. This article examines several techniques which have been proposed to minimize redeposition, including the use of thinner absorbers, gas assisted etching, and simple postrepair trimming. In addition, the capabilities of the current tooling is demonstrated and a comparison of the FIB etch characteristics of several different absorber materials proposed for future mask fabrication (Au, W, and TaSiN) is presented. (C) 1995 American Vacuum Society.