Temperature Characteristics of a-Si:H Gate ISFET

In this paper, we put emphasis on the study of the temperature effect of the ISFET (ion sensitive field effect transistor) based on the hydrogenated amorphous silicon (a-Si:H). Since the temperature influences the properties of the ISFET device, we studied the influence of the temperature effect to ISFET in detail. In this paper, we prepared the a-Si:H/SiO2/p-Si/Al structure of ISFET devices by plasma-enhanced chemical vapor deposition (PECVD). The thickness of the a-Si:H was 2000 Å. Then we used epoxy to encapsulate the a-Si:H pH-ISFET device. Furthermore, we utilized Keithley 236 Semiconductor Parameter Analyzer to measure the I–V curve, and then pH sensitivity of the a-Si:H pH-ISFET was determined. Since the a-Si:H thin film is easily dissolved in alkaline solution, so it was measured in acid solutions between pH 1–7. The experimental results were also compared with the simulated results. We can conclude that the experimental results approximately agree with simulation results.