DC DIELECTRIC-BREAKDOWN IN SIO2-FILMS PREPARED BY LOW-TEMPERATURE CHEMICAL VAPOR-DEPOSITION

In this paper we present the results of an experimental study of the dc dielectric breakdown in SiO//2 films (prepared by low temperature chemical vapor deposition (LTCVD)) as a function of deposition conditions and subsequent annealing in different ambients. The histograms of the percentage relative frequency vs. the breakdown field showed the following. (i) The O//2-to-SiH//4 ratio determines the dielectric quality, the ratio corresponding to the maximum deposition rate, at a given temperature, being optimum. (ii) Subsequent annealings in H//2O vapor at 450 degree C lead to an improvement in the breakdown characteristics of as-deposited layers. (iii) Subsequent annealings in dry N//2 at 1000 degree C have a deleterious effect on the breakdown results. Physical explanations are given.