<title>Characteristics of MSM detectors for meander channel CCD imagers on GaAs</title>

Abstract

Metal-Semiconductor-Metal (MSM) photodetectors on semi-insulating gallium arsenide (SI GaAs) have found widespread application as front-end detectors in receivers for optical fiber communications. Their major attributes are (a) simplicity of design and construction, (b) high responsivity, and (c) high speed of response. In this paper the performance of MSM detectors at short wavelengths is examined and considerations are given for their use in GaAs charge-coupled-device (CCD) imagers. The simplicity of their structure allows MSM detectors to be easily integrated with two-phase meander channel CCD registers in GaAs for production of high speed light scanners. Test results show that GaAs MSM detectors have high sensitivity in the wavelength range from 200 to 800 nm and good linearity over three orders of magnitude variation of the incident incident intensity. These features make MSM detectors potential candidates for both linear and 2D light scanners for ultraviolet (UV) spectrophotometry and astronomy.