CHANNEL HOT-CARRIER STRESSING OF REOXIDIZED NITRIDED OXIDE P-MOSFETS

Channel hot carrier reliability of reoxidized nitrided oxide (RNO) and conventional oxide p-MOSFET's was studied. RNO p-MOSFET degradation is shown to be due to electron trapping, as in oxide devices. Since nitridation introduces electron traps, device lifetimes determined by static stress were found to be lower by 2-3 orders of magnitude in the RNO versus oxide p-MOSFET's. However, circuit life will be determined by the shortest lived device type. For conventional oxide, circuit lifetime is determined by n-MOSFET lifetime. We demonstrate that both RNO n- and p-channel lifetime are many orders of magnitude longer than oxide n-channel lifetimes; so that for submicrometer CMOS, use of RNO is predicted to significantly increase circuit lifetime. Furthermore, X-ray irradiations were found to degrade oxide p-channel hot carrier reliability far more strongly than RNO reliability.