Comparison of transparent conductive oxide thin films prepared by a.c. and d.c. reactive magnetron sputtering

Antomony-doped tin oxide and aluminium-doped zinc oxide films have been prepared by reactive a.c. and d.c. magnetron sputtering (a.c. excitation at frequency of 40 kHz; twin-cathode arrangement) from metallic targets at substrate temperature of about 573 K. The optical, electrical and structural properties of the sputtered SnO2 films of different dopant concentrations have been investigated by means of optical spectroscopy (UV-IR), x-ray diffraction, Hall mobility and conductivity measurements. For antimony-doped SnO2 films a minimum resistivity of 1.5 x 10(exp -3) Omega cm at high transparency (larger than 88 per cent at film thickness of 250 nm) has been observed at dopant concentrations of about 1.2 at. per cent Sb in the lavers. Low resistivity of 4.0 x 10(exp -4) Omega cm and transmission in the visible spectral range of about 89 per cent at film thickness of 550 nm has been optained for a prepared aluminium-doped ZnO thin films.