Dynamics of native oxide growth on CdTe and CdZnTe X-ray and gamma-ray detectors. Issue 1 (1st December 2016)

• Record Type: Journal Article
• Authors: Zázvorka, Jakub; Franc, Jan; Beran, Lukáš; Moravec, Pavel; Pekárek, Jakub; Veis, Martin
• Is Part Of: Science and technology of advanced materials. Volume 17:Issue 1(2016)
• Page Start: 792
• Page End: 798
• Publication Date: 2016-12-01
• Subjects: CdTe -- oxidation -- ellipsometry -- XPS -- leakage current; 40 Optical -- magnetic and electronic device materials -- 212 Surface and interfaces -- 201 Electronics / Semiconductor / TCOs; Materials -- Technological innovations -- Periodicals; 620.112
• DOI: 10.1080/14686996.2016.1250105
• Languages: English
• ISSNs: 1468-6996

Abstract

Abstract: We studied the growth of the surface oxide layer on four different CdTe and CdZnTe X-ray and gamma-ray detector-grade samples using spectroscopic ellipsometry. We observed gradual oxidization of CdTe and CdZnTe after chemical etching in bromine solutions. From X-ray photoelectron spectroscopy measurements, we found that the oxide consists only of oxygen bound to tellurium. We applied a refined theoretical model of the surface layer to evaluate the spectroscopic ellipsometry measurements. In this way we studied the dynamics and growth rate of the oxide layer within a month after chemical etching of the samples. We observed two phases in the evolution of the oxide layer on all studied samples. A rapid growth was visible within five days after the chemical treatment followed by semi-saturation and a decrease in the growth rate after the first week. After one month all the samples showed an oxide layer about 3 nm thick. The oxide thickness was correlated with leakage current degradation with time after surface preparation. Abstract :