The hysteresis and drift effect of hydrogenated amorphous silicon for ISFET

According to the experimental results, the output behavior of the device co nsists of four parts: fast response, slow response, drift and hysteresis. T he hysteresis and drift limit the accuracy obtained from pH-sensitive surfa ce in ion-sensitive field-effect transistors (pH-ISFETs). In this paper, we have studied that hysteresis affects of hydrogenated amorphous silicon (a- Si:H)-gate ISFETs by exposing the device to two cycles of pH values and com pared the hysteresis amounts. In addition, we have measured the drift effec t of a-Si:H at the different pH values and understand the influence of pH v alues for the drift effects of a-Si:H-gate ISFETs. (C) 2000 Elsevier Scienc e S.A. All rights reserved.