New inorganic electron resist system for high resolution lithography

A new Ag2S/As2S3 negative electron resist system is proposed for nanostructure fabrication. Linear gaps down to 30 nm wide have already been resolved. Sensitization of the Ag2S3 with a chemically deposited layer of Ag2S overcomes the limitations involved in the use of silver halides as a source of silver. Although the sensitivity of this resist is very low (4×10−3–10−2 C/cm2) its extremely high contrast (γ>5.5) is an advantage in nanostructure fabrication where it is necessary to discriminate against exposure by backscattered electrons.