Evaluation of temperature dependences of transistor characteristics in n-type, p-type, and pin-type poly-Si TFTs for temperature sensor application

We have evaluated temperature dependences of transistor characteristics in n-type, p-type, and pin-type poly-Si TFTs for temperature sensor application. It is found that the temperature dependences of the off-leakage currents in the n-type and p-type TFTs are much larger than those of the on currents, which are the same results as what were previously reported. Moreover, the temperature dependence of the off-leakage current in the pin-type TFT is as large as those in the n-type and p-type TFTs, which is a novel result obtained in this research. Based on these results, we propose diode connections, where the gate terminals are connected to the source terminals. In comparison with the diode connections of the n-type and p-type TFTs, that of the pin-type TFT has a flowing current relatively independent of the applied voltage, which is especially suitable for temperature sensor application. This is the first presentation reporting the temperature dependences of the pin-type poly-Si TFT and diode connections of the n-type, p-type, and pin-type poly-Si TFTs.