Surface Passivation Effect on CZT-Metal Contact

Abstract

The process of cadmium zinc telluride (CZT) surface passivation is very important to reduce the leakage current of the detector and to improve the detector performance. NH 4 H 2 O 2 solution was identified as an effective passivation agent for CZT. We fabricated a CZT planar detector and measured the detector performances before and after the NH 4 H 2 O 2 passivation. For the first time, the passivation effect on CZT-metal contact was measured. The depth profile of the chemical composition of metal contact was measured with AES to understand the change of the CZT detector performance with passivation.Index Terms-Cadmium zinc telluride (CZT), leakage current, metal-semiconductor contact, surface passivation.

Fabrication of CZT Planar-Type Detectors and Comparison of their Performance

“…The energy resolution of the detector was similiar, however the full peak efficiency was increased after the passivation. The enhancement of the energy spectrum after the passivation was from the removal of the cadmium layer on the gold contact 7) . Fig.…”

Regulation of Te Oxide Layer on Cdznte Film for Adjusting Surface Contact of a Cdznte-Based Device

“…Marchini et al studied that leakage currents can be reduced and contact stability improved by SP [21]. Park et al reported that SP could affect the metal-semiconductor contact, and in return, enhance the peak-to-valley ratio of the energy spectrum [22]. Sang et al proposed a novel twostep CP leads to a lower surface leakage current [23].…”

The X-ray Radiation Response of CdZnTe Crystal Nuclear Detector

“…[4], [12] Research on the improvements of electrode contact, with the purpose of reducing detector leakage currents, has been reported. [5][6][7] On the purpose of getting a better ohmic contact between the contact and the CZT bulk, rapid temperature annealing (RTA) method had been adopted.…”