Study for pulse stress NBTI characteristics degradation stress

NBTI characteristic degradation of MOSFET is still one of important reliability physics in semiconductor device. Although it is well recognized that its degradation is recovered immediately after releasing DC test stress, it is also fact that the voltage which is applied to the gate electrode in most semiconductor device is an intermittent stress like pulse, not consecutive DC stress as NBTI test. Accurate NBTI lifetime prediction method under this pulse stress condition can afford an actual reliable lifetime. In this work, we considered the characteristic recovery phenomenon in pulse NBTI stress with MOSFET of TOSHIBA 40 nm and 90 nm CMOS process technology and examined a more realistic life prediction method.