Title :
Study of Surface Treatment Effects on the Metal-CdZnTe Interface
Author :
Marchini, Laura ; Zappettini, Andrea ; Gombia, Enos ; Mosca, Roberto ; Lanata, Marta ; Pavesi, Maura
Author_Institution :
IMEM- CNR, Parma, Italy
Abstract :
The quality of a CdZnTe-based X-ray detector is highly related to the interface between semiconductor and metal contact. One of the factors that increase leakage currents in CdZnTe based X-ray detectors is the presence of a conductive surface layer. In this paper the result of the passivation of the CdZnTe surface by means of an aqueous solution of NH4F/H2O2 is studied by optical ellipsometry and by the current-voltage characteristics of gold contacts deposited on the oxidized surface. Collected data show that leakage currents can be reduced and contact stability improved by the combined use of the passivation layer and a guard ring.
Keywords :
II-VI semiconductors; X-ray detection; cadmium compounds; ellipsometry; gold; leakage currents; passivation; semiconductor counters; semiconductor-metal boundaries; surface treatment; zinc compounds; CdZnTe-Au; CdZnTe-based X-ray detector; NH4F-H2O2; aqueous solution; conductive surface layer; current-voltage characteristics; guard ring; leakage currents; optical ellipsometry; passivation layer; semiconductor-metal contact; surface treatment effect; Conductivity; Etching; Geometry; Germanium; Leakage current; Passivation; Silicon; Surface resistance; Surface treatment; X-ray detectors; Cadmium zinc telluride; contact resistance; etching; gamma-ray detectors; oxidation; surface treatment;
Journal_Title :
Nuclear Science, IEEE Transactions on
DOI :
10.1109/TNS.2009.2022831
