Evaluation of NH₄F/H₂O₂ effectiveness as a surface passivation agent for Cd_1-xZn_xTe crystals

Various passivating agents that reduced the surface leakage current of CZT crystals have been previously reported. In one of the studies, NH₄F/H₂O₂ was identified as a promising passivation agent for CZT. We now present a study that includes the effect of NH₄F/H₂O₂ treatment on the surface properties and detector performance. An elemental depth profile was obtained via Auger Electron Spectroscopy. Furthermore, X-ray Photoelectron Spectroscopy acquired at different processing times to identify the chemical states of the elemental species that composed the dielectric layer. It was found that the NH₄F/H₂O₂ surface passivation significantly improved the sensitivity and energy resolution of CZT detectors. Furthermore, the NH₄F/H₂O₂ treatment did not attack the Au electrodes, which eliminated the need to protect the contacts in the detector fabrication process.