Characterization of a-Si:H based metal/insulator/semiconductor structures by feedback charge capacitance-voltage measurements and charge deep-level transient spectroscopy

We have measured feedback charge capacitance-voltage (C-V) characteristics and spectra of the charge deep-level transient spectroscopy (QDLTS) on hydrogenated amorphous silicon (a-Si:H) based metal/insulator/semiconductor structures with different a-Si:H and insulator layer thicknesses. The measured QDLTS spectra are quite complicated ones, pointing to an inhomogeneous density of states in a-Si:H which is confirmed by the obtained distribution of bulk traps in energy and space. Despite this fact we are able on the basis of the feedback charge C-V method to determine the flatband voltage and the electron threshold voltage of a thin-film transistor based on a-Si:H without subjecting it to thermal bias stressing. (C) 1997 American Institute of Physics. [S0021-8979(97)07720-7].