<title>Laser-beam-induced current technique as a quantitative tool for HgCdTe photodiode characterization</title>

Abstract

A non-destructive optical characterization technique is used for the investigation of HgCdTe photovoltaic devices. The technique uses a scanning laser microscope to obtain Laser Beam Induced Current (LBIC) data from which it may be possible to extract information such as junction depth, array uniformity, and other material and device parameters. LBIC has been previously used only as a qualitative technique, but in this work the procedure is being developed into a quantitative tool. At present the only junction depth profiling techniques are destructive, while array uniformity can only be examined after bonding to readout circuits. In this paper we present both theoretical and experimental; results which show that LBIC can be employed as a quantitative tool for device characterization. The primary measure of performance of IR detectors is the zero bias dynamic resistance junction area product, R0A. LBIC measurements indicate that the peak LBIC signal varies by a factor of approximately 2 for long wavelength RI photodiodes for which the R0A varies between 70 (Omega) cm2 and 8 (Omega) cm2.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.