Characterization of semi-insulating GaAs for detector application

• Published in: Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment Accelerators, spectrometers, detectors and associated equipment, 1996-10, Vol.380 (1), p.14-17
• Main Authors: Rogalla, M, Chen, J.W, Geppert, R, Kienzle, M, Irsigler, R, Ludwig, J, Runge, K, Fiederle, M, Benz, K.W, Schmid, T.H, da Via, C, Lauxtermann, S, Liu, X, Krueger, J, Weber, E.R
• Format: Article
• Language: English
• ISSN: 0168-9002; 1872-9576
• DOI: 10.1016/S0168-9002(96)00290-2

Schottky diodes made of semi-insulating (SI) gallium arsenide and bulk material received from various manufactures were studied by using magnetic circular dichroism of absorption (MCDA), near-infrared absorption (NIR), CV- and Hall-measurements. The results have been analysed to investigate the influence of the EL2/EL2 +-concentration to the detector properties. The MCDA measurements of these different materials showed a variation of the EL2 +-concentration between 3.0 and 6.5 × 10 15 cm −3. A likely dependence of the charge collection efficiency (CCE) for alpha particles on the EL2 +-concentration was observed. Also an influence of the EL2 +-concentration on the space charge density measured by CV and the leakage current density can be seen. No correlation between the room temperature mobility and the EL2 +-concentration was found. We conclude that the EL2 +-concentration and the position of the Fermi level have a influence on the detector performance.