The influence of oxygen partial pressure and total pressure ( O2 + Ar) on the properties of tin oxide films prepared by dc sputtering

Abstract

Tin oxide films have been prepared on glass substrates by dc reactive magnetron sputtering using a metallic tin target of 99.99% purity (100×100×2 mm 3) in an argon and oxygen mixed atmosphere. The influence of the oxygen partial pressure and total pressure on the X-ray diffraction, transmittance, resistivity, optical band gap, refractive index, packing density and deposition rate have been investigated systematically. When oxygen partial pressure is lower than 4×10 −3 mbar , the films show an amorphous structure and are not transparent in the visible region but are transparent in the near IR region. When oxygen partial pressure is between 4×10 −3 mbar and 6×10 −3 mbar, the films show a good polycrystalline structure, a high transmittance in the visible and near IR regions and a high packing density. When oxygen partial pressure is higher than 6×10 −3 mbar, the film structure deteriorates and the film packing density decreases. At fixed oxygen partial pressure, the film prepared at low total pressure has better structure and higher packing density than that prepared at high total pressure.