Thermal decomposition of copper nitride thin films and dots formation by electron beam writing

Copper nitride (Cu 3N) thin films were prepared on glass substrates by reactive rf magnetron sputtering. The film was decomposed into Cu film by heating 450°C for 30 min. Nitrogen gas effused from the Cu 3N film during the heating. The decomposition initiation temperature of the films was about 360°C, and the thermal analysis involved thermogravimetry (TG) as well as a detection of N 2 + ion that effused from the films during heating in a vacuum. Electron beam processing was used to decompose Cu 3N into Cu. A dot array of 3 μm×3 μm and 1 μm×1 μm was obtained on the Cu 3N film after electron beam irradiation. The Cu 3N films easily dissolved in the dilute HCl solution. The etching rate of the Cu 3N film in 100 g/l HCl aqueous solution was 3900 times that of the Cu film.