Observation of Thermally Generated Carrier in Charge Coupled Devices

Abstract

The build-up of thermally-generated carriers in a charge coupled device (CCD) is investigated by considering a generation model proposed by Zerbst that characterizes the transient response of an MOS capacitor. By applying clock pulses in a holding mode to a pair of electrodes of a 4-phase, 128-bit CCD shift register, noise signals of the generated carriers were observed when the duration of the holding mode reached several msec. By comparing experimental results with the theoretical transient response derived from the Zerbst model, the minority carrier lifetime τ and the surface generation velocity SG are determined to be in reasonable agreement with the values evaluated from transient responses of the MOS capacitor.