Evidence of oxide charge trapping saturation induced by rapid thermal annealing

In this paper, we investigate the impact of Rapid Thermal Annealing temperature on hot electron reliability by using DC stress measurement and two dimensional device simulation. We find that the substrate current of sample with Rapid Thermal Annealing temperature higher than 900/spl deg/C degrades with time, while substrate current of sample with 875/spl deg/C shows an anomalous variation, that is, two section saturation phenomenon. We propose the physical explanations about two section saturation phenomenon. Finally, we also verify other model to find out the characteristic of gate oxide. We find that the sample with higher Rapid Thermal Annealing temperature has better oxide quality to avoid hot electron injection.