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

Abstract

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 $\mathrm{a-}\mathrm{Si:H}$ channel material, and thus reduces the effective electron mobility.