ETCHING, INSERTION, AND ABSTRACTION REACTIONS OF ATOMIC DEUTERIUM WITH AMORPHOUS-SILICON HYDRIDE FILMS

We report structural and kinetic studies of the reactions of hydride s pecies in Si thin films with atomic deuterium (D-at). Infrared (IR) sp ectroscopy is used to obtain Si-H bonding information, and direct reco iling methods are used to measure reaction rates. Two kinds of films a re prepared by filament-assisted growth from Si2H6 and are characteriz ed by IR spectroscopy. A film containing only monohydride hydrogen is grown at 200 degrees C, and a polymer containing tri-, di-, and monohy dride is grown at -110 degrees C. Rates of H abstraction by D-at, and of D-at insertion into Si-Si bonds, are reported. The abstraction rate of H by D-at in both films is similar, to the abstraction rate on H-t erminated crystal Si surfaces. The insertion rate into Si-Si bonds in both films is about one-tenth the rate of abstraction. A qualitative s tudy of the etching reaction of D-at with the polymeric film is report ed, and a strong temperature dependence is observed.