Simulation of charge transfer in GaAs cermet-gate CCDs

Computer simulations of charge transport in GaAs cermet-gate charge-coupled devices (CCDs) are reported. A finite difference scheme was used to simulate charge evolution between successive clock phases. Epi-grown and ion-implanted channels were considered. As observed, the charge transport, and hence the transfer inefficiencies of these devices, depended on the relative importance of the drift field and the self-induced field more than the diffusion contribution. While the self-induced drift effect aided the charge transport at the initial phase, its effect at the final stage of charge transfer would be to reverse the charge transport. Velocity saturation effect is another limiting factor affecting charge transfer. Both the velocity saturation effect and the reverse self-induced drift effect were responsible for the retardation of the charge transfer.<
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