Fluorinated InGaZnO Thin-Film Transistor With HfLaO Gate Dielectric

Fluorinated amorphous InGaZnO thin-film transistor with HfLaO gate dielectric has been studied by treating InGaZnO film in a CHF
₃
/O
₂
plasma. The saturation carrier mobility can be improved from 29.6 cm
²
/V·s to as high as 39.8 cm
²
/V·s. In addition, the passivation effect of the fluorination on the dominant donor-like traps at the InGaZnO/HfLaO interface is observed, as reflected by suppression of hysteresis phenomenon and smaller subthreshold swing. Measurement result of low-frequency noise further supports the improvement in electrical properties by the plasma treatment.