Role of electrode technology in radiation detector based on semi-insulating InP in development of detector array

In this work the role of electrode technology of a radiation detector based on Liquid Encapsulated Czochralski semi-insulating (SI) InP is investigated with emphasis on the development of a monolithic array of pixel detectors. Two different electrode technologies are applied: (i) Au evaporation to form a metal-semiconductor-metal structure with a quasi-Schottky barrier, and (ii) MOCVD of a p(+) layer for the creation of a pin structure using the same SI InP base. The I V characteristics and pulse height spectra of Am-241 and Co-57 are measured at room and lower temperatures and evaluated. The observed results show different electrical as well as detection performance of fabricated structures. Mechanical sawing and wet etched trench methods are applied with the aim of reducing electrical charge inter-diffusion between neighbouring, strip detectors as a preliminary study to the fabrication of a segmented, monolithic detector array based on SI InP. SM and I-V methods are used for the evaluation of the wet chemical process used. The observed results and future works are discussed in view of results obtained within the study. (C) 2004 Elsevier B.V. All rights reserved.