High field effect mobility deuterated amorphous silicon thin-film transistors based on the substitution of hydrogen with deuterium

The characteristics of amorphous silicon hydrogen and deuterium thin-film transistors (a-Si:H/a-Si:D TFT) were studied. The deuterated and hydrogenated amorphous silicon channels were prepared by first annealing the as-deposited a-Si:H layer at 550 degrees C in N-2 environment to expel all the hydrogen atoms out of the films, then the D-2 or H-2 plasma were applied to treat the amorphous silicon layers. The field effect mobility of the conventional hydrogen TFT is usually smaller than 1 cm(2)/V-s. It was found that substitution of hydrogen with deuterium improved the field effect mobility of the TFT, The maximum field effect mobility of a-Si:D TFT obtained from the saturation region was 1.77 cm(2)/V-s.