Electron mobility in amorphous silicon thin-film transistors under compressive strain

We evaluated amorphous silicon thin-film transistors under uniaxial compressive strain of up to 1%. The on-current and hence the electron linear mobility decrease. The off-current, leakage current, and the threshold voltage do not change. The mobility decreases linearly with applied compressive strain. Upon the application of stress for up to 40 h the mobility drops instantly and then remains unchanged. We conclude that compressive strain broadens both the valence and conduction band tails of the a-Si:H channel material, and thus reduces the effective electron mobility. (C) 2001 American Institute of Physics.