Temperature characterization of amorphous silicon:hydrogen TFT for analog circuit design using AHDL modeling.

摘要

A characterization of the hydrogenated amorphous silicon thin film transistor (a-Si:H TFT) under varying ambient temperature is essential to the successful design of any circuits that use a-Si:H TFTs as analog devices. The backplane circuit of an active matrix organic light emitting diodes (AMOLED) display is one such applications which will use the a-Si:H TFT in its pixel control circuitry. In this study, a multitude of a-Si:H TFTs under different manufacturing processes as well as varying in sizes are subjected to temperature ranging from -40°C to 100°C, while their transfer characteristics are being measured. The collected data is used to extract the various parameters that govern the TFT's characteristics such as power parameter alpha, threshold voltage Vt, and effective mobility mu eff. The parameters are analyzed to retrieve their dependence on ambient temperature, which is subsequently incorporated in Verilog-A to expedite circuit designs and analysis under diverse temperature environments. The simulation has proven to be accurate and provide circuit designers with a low cost and efficient tool to verify their design.