New device degradation due to 'cold' carriers created by band-to-band tunneling

Device degradation caused by so-called 'cold' carriers due to band-to-band tunneling in a MOS drain region is studied. The cold carriers acquire energy from the electric field in the drain region and surmount the Si-SiO/sub 2/ barrier. In an n-channel device, injected holes cause a decrease in the tunnel current and a negative MOS threshold-voltage shift opposite to that observed in hot-carrier degradation previously reported. A simple analytical model is presented. This model agrees well with the experimental data in both n- and p-channel devices.<
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