In¯uence of UV light irradiation on ®lm thickness distribution of tin oxide ®lms by photochemical vapour deposition

Tin oxide (non-doped) ®lms have been prepared by a photochemical vapour deposition (photo-CVD) from Tetramethyltin (TMT) (Sn(CH3)4) and O2 (containing O3). A low-pressure mercury lamp was used as the light source. The effect of the UV light irradiation on the ®lm thickness distribution along 5 cm 5 cm area was examined. By piling Te¯on ®lms on the surface of the suprasil window, the light intensity of 184.9 nm UV wavelength of the low-pressure mercury lamp was controlled, while that of 253.7 nm wavelength through the Te¯on hardly changed. As a result, the uniformity of the ®lm thickness distribution was improved as the light intensity (184.9 nm) increased. The UV 184.9 nm light irradiation may have improved the uniformity of the reactive species distribution in the vapour phase, which may result in the formation of the uniform thickness distribution. # 2001 Elsevier Science B.V. All rights reserved.