NUMERICAL-ANALYSIS OF ISFET AND LAPS DEVICES

In this paper, a numerical simulation technique suitable for device-le vel analysis of ion-sensitive devices (ion-sensitive field-effect-tran sistor (ISFET) and light-addressable potentiometric sensor (LAPS)) is presented. Models of the change lavers which develop at the electrolyt e-insulator interface of an electrolyte insulator-semiconductor (EIS) system are incorporated into the device equations. thus providing a se lf-consistent picture of charge and field distribution within the semi conductor domain. To accomplish the simulation of LAPS devices, an AC- modulated optical generation rate has been introduced as well. A TCAD tool, based on the proposed approach, has been developed, which allows for the electrical characterization and for the extraction of circuit -simulation parameters of ion-sensitive devices. Validation of the dev ice-analysis technique comes from the comparison between predicted ele ctrical responses and actual device measurements. (C) 1997 Elsevier Sc ience S.A.