Electrical characteristics and thermally induced metastability in an amorphous-silicon ambipolar transistor

Electrical characteristics and thermally induced metastability in a boron-doped hydrogenated amorphous silicon (a-Si:H) thin-film transistor (TFT) deposited at 180 degrees C are discussed. The on/off ratio of the conductance and the field-effect mobility are similar to those for undoped a-Si:H TFTs. The device characteristics exhibit n- and p-channel operations. The enhancement in the drain currents caused by double injections of electrons and holes appears for the p-channel operation of the TFT. Thermal quenching experiments on boron-doped a-Si:H silicon-nitride ambipolar TFTs give clear evidence of the coexistence of two distinct metastable changes: the metastable creation of the active dopants and dangling bonds appear to increase with quenching temperature.>