Activation hydrogen diffusion

For completeness it should be mentioned that the passivation of gold, presumably via the same AuH complex, has also been studied in p-type silicon, where it is the donor rather than the acceptor level of gold that is active (Hansen et al., 1984). Though no profiles were reported in this work, apparent hydrogen diffusion coefficients inferred by these authors are of the same order as the Pearton (1985) points of Fig. 16 at temperatures 110°C and below. 

The concentration profile studies find that the hydrogen diffusion coefficient in a-Si H is thermally activated, as shown in Fig. 17 (Street et al., 1987). Over the temperature range of 130 to 300°C, the diffusion data is described by the Arhennius expression... 

Determinations of active hydrogen with methyllithium and with methylmagnesium iodide were undertaken by Uytterhoeven and Fripiat (366). Only after outgassing at 600° or higher, did the results of both methods agree with each other and with the weight loss on calcination. The reactions proceeded more slowly than with Aerosil silica (195). Apparently, diffusion into the pores is hindered, especially with the Grignard compound. 

Fig. 28. Representation of a hydrogenated field effect transistor. The carrier concentration in the active layer is controlled, before the gate deposition, by the hydrogen neutralization of the donors present in the highly silicon doped layer. The insert shows the free carrier concentration gradient from the gate, which results from the hydrogen diffusion. J. Chevallier and M. Aucouturier, Ann. Rev. Mater. Sci. 18, 219 (1988). Annual Reviews Inc.

The hydrogen diffusion coefficients shown in Pig. 2.20 are thermally activated. 

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