Binary-Solvent Developer for Cross-Linked Positive-Tone Resists

A new binary-solvent developer has been developed for a cross-linked positive-tone resist called suppressed aggregate extraction development (SAGEX) resist. It is composed of a good solvent and a poor solvent that does not produce swelling in the resist polymer. Hydrocarbon, such as n-hexane, was used as a poor solvent in this study because alcohol, which is conventionally used as a poor solvent, was not effective. A hydrocarbon, which causes little swelling of the base polymer, reduces the dissolution of lightly exposed SAGEX resist in a good solvent. As a result, with this developer, a high contrast can be obtained and resist residue can be eliminated at the same time. In addition, this developer has been shown to be effective in reducing resist roughness; that is, it helps reduce the line-edge roughness of resist patterns to 1 nm or less.