Hot-carrier-induced degradation of the back interface in short-channel silicon-on-insulator MOSFETS

The tolerance of silicon-on-insulator MOSFETs to hot-carrier injection into the buried oxide is investigated. It is shown that stressing of the back channel results in reversible electron trapping and formation of localized defects at the buried interface. This damage is responsible for the transconductance overshoot, large threshold voltage shift, and attenuated kink effect. It is also noticed that even in moderately thin films the back oxide damage does not affect the front-channel operation and, conversely, stressing the front channel does not generate defects at the buried interface. These findings indicate that the hot-carrier degradation of the buried oxide might be chosen as a sensitive criterion for optimizing SIMOX (separation by implantation of oxygen) structures.<
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