Effect of low temperature deuterium annealing on plasma process induced damage

The effects of low temperature deuterium annealing on plasma process induced damage were examined for devices with a thin gate oxide. The devices were exposed to the plasma during poly-Si gate or metal processes, and the device characteristics were monitored by charge pumping and current-voltage measurements. It was observed that the metal process induced more plasma damage than the poly-Si gate process. The deuterium (D/sub 2/) annealing had little effect on oxide damage, but it was very effective in reducing the interface damage. After D/sub 2/ annealing, the devices showed a very low level of interface states, and the strength to withstand electrical stress was also enhanced. To maximize D/sub 2/ annealing effects, it is suggested that the D/sub 2/ annealing should be conducted without any H/sub 2/ annealing.