The increase in the demand of sub-10 nm feature size in semiconductor industries necessitates a new kind of resist material development which can absorb a large fraction of irradiation and retains the small size cluster distribution (1-2 nm). In this context, we developed a novel nickel-based organo-metallic cluster comprising high optical density inorganic nickel as metal building units (MBU), and 3,3-Dimethylacrylic acid as an organic ligand to form Ni-DMA clusters. The synthesised clusters have ~1 nm size with narrow size distribution. The formulated resist shows the negative tone pattern when exposed with a focused helium ion (He<sup>+</sup>) beam and e-beam. The high-resolution line patterns of ~8 nm at the dose of ~40 μC cm<sup>-2</sup> were obtained with the minimum line edge roughness (LER) and line width roughness (LWR) of 2.16 ± 0.04 nm and 3.03 ± 0.06 nm, respectively.