X-ray lithography for ≤100 nm ground rules in complex patterns

Abstract

Complex patterns with 75-125 nm feature sizes exposed with x-ray lithography are shown. Lithographic results for 75-125 nm lines with varying pitch are compared to simulations of image formation and resist dissolution, showing good qualitative agreement. Exposure dose latitude, nested-to-isolated print bias, image shortening, linewidth change with gap, and linearity of printed linewidth versus mask linewidth are quantified for 11-22.5 μm gaps. Critical dimension control error budgets for resist linewidth uniformity are determined for logic patterns at 75 and 100 nm ground rules. Image shortening is quantified for 75-125 nm ground rule static random access memory-like patterns, indicating hammerheads added to line ends reduce shortening to acceptable levels for ≥ 100 nm ground rules at ≤ 17.5 μm gaps. With tight gap control and tight mask linewidth control, 100 nm ground rule complex patterns can be printed with good latitude using x-ray lithography. © 1997 American Vacuum Society.