High-precision motion and alignment in an ion-beam proximity printing system

Abstract

We measure the fluorescent alignment generated by ion bombardment of an SiO2 wafer mark scanned behind a corresponding window pattern in a silicon stencil mask. We conclude that an optimized system can align to 50 nm (mean+3σ) in less than 300 ms. Throughput is shown to be limited not by the alignment system, but by thermal loading of the mask during exposure.