Selective area laser photodeposition of transparent conductive SnO2 films

The deposition of SnO2 films has been demonstrated using an ArF (193 nm) excimer laser to drive the photochemical reactions of mixed SnCl4 and N2 O vapors. Without any annealing, films 100 nm thick grown on room-temperature substrates have resistivities as low as 0.04 Ω cm. The optical band gap of 3.20 eV and transmission cutoff wavelength of 330 nm compare favorably with the best films obtained using alternate higher temperature techniques. Subsequent annealing does not increase the film’s conductivity. Selective area growth of 10-μm-wide lines has been performed using proximity printing. The maximum temperature excursion during the laser pulse is estimated to be 300–400 °C.