250-Å linewidths with PMMA electron resist

Abstract

25‐nm‐wide lines and spaces have been fabricated in 22.5‐nm‐thick films of PdAu (40 : 60) using electron‐beam exposure and polymethylmethacrylate (PMMA) resist. A high‐resolution scanning transmission electron microscopy (STEM) was used to expose the resist and the samples were mounted on 60‐nm‐thick Si₃N₄ membrane substrates. Previously, the smallest metal structures formed with a resist process were 60 nm wide with spaces between the lines several times larger than the lines. The results presented here show that 25‐nm lines can be fabricated with a center to center spacing of 50 nm.