Effect of electron traps on reversibility of annealing

The kinetics of rechargeable radiation induced electron traps build-up in MOSFETs is investigated. The recharge of these traps is responsible for the threshold voltage forward and reverse annealing under altered polarity gate bias. The electron traps are expected to be shallow with energy levels close to the SiO2 conductance band. These traps are shown to be generated through the free electrons capture by trapped holes and to be annihilated through free hole capture by the trapped electron. The experiments were carried out to establish electron traps build-up dependence on the oxide electric field. The electron traps are expected to play a significant role in oxide fixed charge yield because of the large cross-section value for the free hole-trapped electron recombination. The correlation between interface traps in the upper half of Si forbidden gap and electron traps located close to the interface is also discussed.