Binary solvent developer for cross-linked positive-tone resists

To suppress aggregate extraction development and thus reduce line edge roughness (LER), we have developed a three-component cross-linked positive-tone resist, which we call a suppressed aggregate extraction development (SAGEX) resist. However, the exposure dose required for pattern delineation is greater in SAGEX resists. In particular, when we use a conventional developer for the base polymer, such as n-hexyl acetate, the resist residue tends to remain. In this article, we investigate the development conditions for SAGEX resists to overcome this drawback. We find that the use of a binary solvent developer consisting of a good solvent and a nonpolar solvent reduces both the exposure dose and the surface roughness in SAGEX resists.