Improvement of Electrical Characteristics of a-Si:H Thin Film Transistors by Hydrogen Plasma Back-Channel Ethcing Method

In this article, we have investigated the electrical characteristics of hydrogen plasma etching on the back channel of thin film transistors in comparison with convention conventionally back-channel from 0.24 cm2/V · s to 0.38 cm2/V · s. Back channel etch using hydrogen plasma makes it possible to obtain much better on-current characteristics than are obtained with conventional channel-etch by SF6 plasma. At the same thickness of amorphous Si at 200 nm, field-effect mobility of thin film transistors using hydrogen plasma back channel etching is improved about 37% than using SF6 plasma. The effects of the hydrogen plasma etching on the amorphous Si were checked using current-voltage plotter, atomic force microscopy and Fourier Transform Infrared spectrometry.