We developed a novel negative-tone resist platform based on multi-benzyl chloride modified molecular glasses with low molecular weight (< 800 Da) to address the resist challenges of electron beam lithography (EBL) and extreme ultraviolet lithography (EUVL). The molecular glasses with different substitution positions of chloromethyl group (designated as AD4xCl, x = O, M, and P, representing the ortho-, meta-, and para-substitution, respectively) were designed, synthesized, and their resists’ lithographic performance were evaluated. Feature sizes as small as 16 nm half-pitch (HP) were achieved using EBL, and a significant effect of the substitution positions on the resolution and sensitivity was observed. The atomic force microscopy (AFM) measurement confirmed the difference in substituent positions significantly affects the self-crosslinking efficiency and mechanical strength of the resist films, which is the main reason for the differences in sensitivity and resolution limits. The meta-substituted AD4MCl molecule resist exhibited the best performing and was further investigated by EUVL, achieving an impressive 13 nm pattern with a line edge roughness (LER) of 2.6 nm at an exposure of 137.9 mJ cm -2 . Mechanism studies demonstrate EUV-induced self-crosslinking of multi-benzyl radicals among the AD4MCl molecules drives the solubility switch, enabling high-resolution negative-tone patterning.