A New Inorganic Electron Resist Using Amorphous WO3 Film

Abstract
It was found that amorphous WO3 films become insoluble in alkaline solutions after electron-beam irradiation. Exposure characteristics show that threshold doses required for this effect increase with increasing incident electron energy and film thickness. The blue coloration simultaneously obtained by electron-beam irradiation is not directly responsible for the change in the solubility. This inorganic electron resist has some advantageous features in resolution, contrast, resistance to heat and acid, and ease of the processing.