Ice lithography using tungsten hexacarbonyl

Ice lithography (IL) fabricates 2D and 3D patterns using electron-solid interaction principle. Herein, we report IL patterning of the negative tone metalorganic precursor. The precursor is condensed at 80 K. It is then patterned using a 5–20 keV electron beam. The pattern thickness and surface roughness increase with area dose. The line thickness and linewidth also increase with the growing line doses. XPS results show that tungsten is bound to oxygen; metallic and WC bonds are absent, which suggests the IL patterned tungsten hexacarbonyl contains oxidized tungsten embedded in carbon and oxygen matrix. Finally, the IL patterned tungsten hexacarbonyl was investigated as an etch mask for nanofabrication applications. The silicon plasma etching selectivity is 30:1, comparable with commercial photoresists.