High-resolution Positive Resists for Electron-beam Exposure

This paper examines the utility of four newly proposed positive resists whose processing combines electron-beam-induced degradation of certain polymers and, subsequently, in situ fractionation according to molecular weight. Positive-resist action in four systems formulated on this concept has been demonstrated. Typical sensitivity in electron-beam exposure is 10
⁻⁴
coulomb/cm
²
. Two resists exhibit resolution better than 1 micron. One resist investigated in detail yields extremely clean edges in electron-beam exposure, is resistant to hydrofluoric acid etching baths, and appears otherwise applicable to the fabrication of circuit elements of submicron size.