Proposal for Recovery Method of pH Sensor Characteristic Fluctuation Due to Charging Using Striped Gate ISFETS

Our group have been developing a stripe-gate type pH sensor. It had achieved long-term continuous measurement. However, a characteristic fluctuation causing a problem of drift was sometimes observed before the start of measurement. The cause of this was thought to be sensor charging due to electro-static discharge (ESD) or other factors. We first investigated the effect of sensor charging on continuous measurement. It was succeeded in reproducing the occurrence of drift due to charging. We also succeeded in removing the generated charge and confirmed that drift was suppressed in continuous measurement after removal.