A novel water developable tetraphenyltin-based nonchemically-amplified molecular resist for sub-13 nm lithography

A single-component nonchemically-amplified resist (n-CAR) based on a tetraphenyltin derivative (SnMSF4) was developed for electron beam and extreme ultraviolet lithography. The structure of SnMSF4 was characterized by 1H NMR, 19F NMR, HRMS, FTIR spectroscopy, and elemental analysis. SnMSF4 exhibits good thermal stability, and its non-planar structure makes it have good film-forming performance, which makes it suitable for resist materials. SnMSF4 can be used as a negative resist developed with water (H2O), mixtures of ethanol (EtOH) and H2O (VEtOH : VH 2 O = 1 : 10–20), or mixtures of isopropyl alcohol (IPA) and H2O (VIPA : VH 2 O = 1 : 10–20). Electron beam lithography (EBL) studies revealed that 20 nm features were successfully patterned using the SnMSF4 resist. Moreover, the study of extreme ultraviolet lithography (EUVL) performance shows that 13 nm line/space (L/S) patterns were successfully patterned at a dose of 163 mJ cm−2 with a line edge roughness (LER) of 3.3 nm. Further studies on the underlying mechanisms showed that the solubility change of the SnMSF4 resist depends on the decomposition of the sulfonium group. This research will provide useful guidance for the research of high-resolution electron beam and EUV resist materials.