The intrinsic breakdown strength of thin films which had been produced by the plasma-enhanced chemical vapor deposition of tetraethoxysilane was measured by using a self-healing technique which involved the application of short voltage pulses. Point defects in the films were examined by using optical absorption and luminescence methods under synchrotron radiation. It was found that the intrinsic breakdown strength decreased when the deposition temperature was higher than 400C, even though the optical gap and the density increased and the impurity content decreased. On the basis of the fact that films which were deposited at high temperatures exhibited absorption at 7.6eV and luminescence at 4.4eV, the existence of O vacancies (Si-Si) was deduced. The intrinsic breakdown strength was increased by decreasing the number of O vacancies via O treatment. From the results, it was concluded that O vacancies played a crucial role in decreasing the breakdown strength.

K.Ishii, D.Isshiki, Y.Ohki, H.Nishikawa, M.Takiyama: Japanese Journal of Applied Physics, 1995, 34[I-1], 205-11