Study of Chemical Etching and Chemo-Mechanical Polishing on CdZnTe Nuclear Detectors
Study of Chemical Etching and Chemo-Mechanical Polishing on CdZnTe Nuclear Detectors
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CdZnTe核探测器化学刻蚀和化学机械抛光研究
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
R. James
中科院分区：
文献类型：
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作者：
A. L. Adams;S. Egarievwe;E. Agbalagba;R. Gul;A. Hossain;U. Roy;R. James
碲锌镉（CdZnTe）半导体可在室温下探测X射线和伽马射线，而无需使用冷却系统。化学蚀刻和化学机械抛光是用于在探测器器件制造期间平滑CdZnTe晶片的工艺。这些工艺减少了抛光晶片后留下的表面损伤。在本文中，我们比较了腐蚀和化学机械抛光对CdZnTe核探测器的影响，使用溴化氢在过氧化氢和乙二醇的混合物的溶液。X射线光电子能谱（XPS）被用来监测晶片表面上的TeO 2。电流-电压和探测器响应的测量进行了研究的电气性能和能量分辨率。XPS结果表明，化学蚀刻过程导致更多的TeO 2形成的探测器表面相比，化学机械抛光。探测器的电阻率为1010 Ω-cm量级。化学机械抛光工艺比化学蚀刻工艺增加更多的漏电流。对于新处理的表面，与化学机械抛光相比，蚀刻工艺对能量分辨率更有害。
Cadmium zinc telluride (CdZnTe) semiconductor has applications in the detection of X-rays and gamma-rays at room temperature without having to use a cooling system. Chemical etching and chemo-mechanical polishing are processes used to smoothen CdZnTe wafer during detector device fabrication. These processes reduce surface damages left after polishing the wafers. In this paper, we compare the effects of etching and chemo-mechanical polishing on CdZnTe nuclear detectors, using a solution of hydrogen bromide in hydrogen peroxide and ethylene glycol mixture. X-ray photoelectron spectroscopy (XPS) was used to monitor TeO2 on the wafer surfaces. Current-voltage and detector-response measurements were made to study the electrical properties and energy resolution. XPS results showed that the chemical etching process resulted in the formation of more TeO2 on the detector surfaces compared to chemo-mechanical polishing. The electrical resistivity of the detector is of the order of 1010 Ω-cm. The chemo-mechanical polishing process increased the leakage current more that chemical etching. For freshly treated surfaces, the etching process is more detrimental to the energy resolution compared to chemo-mechanically polishing.