Polysilicon N-channel TFT have been hydrogenated using the H2 dissociation on a hot tungsten filament. A post-annealing realized at the optimal temperature of 300°C is necessary to obtain interesting electrical TFT characteristics. Different TFT's sizes and geometries have been processed. The analysis of their characteristics shows that hydrogen preferentially diffuses through silicon oxide layer. The enhancement of the current in the ON-state shows that hydrogen atoms have passivated silicon oxide gate / polysilicon interface traps. The important reduction of the dependency of the OFF-state current with the reverse gate voltage shows that hydrogen atoms have passivated grain boundary traps near the interface in the channel region and in the drain sheet resistance region then reducing the trapped carrier emission.

The luminescence of erbium implanted in hydrogenated amorphous silicon (a-Si : H) is presented. For the first time an intense and relatively sharp luminescence at 1.54 mm is observed in a-Si : H, using implanted erbium. The Er+ emission intensity strongly depends on the hydrogen film content and on the measurement temperature. A direct correlation between the optical gap energy of the semiconductor and the hydrogen film content is observed.

The luminescence of erbium implanted in hydrogenated amorphous silicon (a-Si : H) is presented. For the first time an intense and relatively sharp luminescence at 1.54 mm is observed in a-Si : H, using implanted erbium. The Er+ emission intensity strongly depends on the hydrogen film content and on the measurement temperature. A direct correlation between the optical gap energy of the semiconductor and the hydrogen film content is observed.