CrSb2Te thin film as a dry resist and its etching mechanism for lithography application

Abstract Lithography has important applications in chip manufacturing, micro-electro-mechanical system, nanostructure fabrication, et al. Photoresist is a key factor for the lithography. However, current organic resists suffer from poor line-edge roughness, environmentally unfriendly, et al. In parallel, conventional wet development can readily cause the undercut of photoresist due to its isotropic etching. In this work, CrSb2Te thin film, as an inorganic resist, was prepared and its etching characteristics were investigated via dry development with CHF3/O2 mixed gases. It is found that superior etching selectivity can be realized in the CrSb2Te thin film. In order to elucidate the lithography characteristics, XRD, EDS, XPS, and Raman spectra are obtained. The results indicate that laser irradiation leads to the generation of Sb crystals and CrSb2Te3 phase. According to dry etching, Sb crystals of the laser-irradiation film can be readily broken. On the other hand, the as-deposited thin film possesses higher etching resistance owing to the uniform distribution of Cr in Sb2Te along with the formation of Cr-Sb and Cr-Te bonds. Therefore, CrSb2Te thin film may be utilized as a superior inorganic resist for the field of lithography.