Latent thermally activated interface-trap generation in MOS devices

A large increase in interface-trap density (up to a factor of five) has been observed in commercial MOS devices at very long times after irradiation (>10/sup 6/ s). This latent buildup occurs after an initial apparent saturation of interface-trap density, which occurs typically within approximately 10/sup 2/-10/sup 4/ s after irradiation. The latent buildup is thermally activated. with an activation energy of approximately 0.47 ev. Within experimental uncertainty, this is equal to the activation energy ( approximately 0.45 eV) for the diffusion of molecular hydrogen in bulk fused silica. Latent interface-trap buildup can degrade the performance of devices in low-dose-rate radiation environments (e.g. space).<
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