Investigation on the surface treatments of CdMnTe single crystals
Investigation on the surface treatments of CdMnTe single crystals
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CdMnTe单晶表面处理研究
DOI：
10.1016/j.mssp.2014.12.051
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发表时间：
2015-03-01
影响因子：
4.1
通讯作者：
Meng, Hua
中科院分区：
文献类型：
--
作者：
Shen, Min;Zhang, Jijun;Meng, Hua
CdMnTe晶体的表面质量对核辐射探测器的性能有重要影响。本文研究了机械抛光(MP)、化学抛光(CP)、化学机械抛光(CMP)和化学机械抛光+化学抛光(CMP+CP)处理的CdMnTe样品的表面。用高分辨扫描电子显微镜(HRSEM)、原子力显微镜(AFM)和X射线光电子能谱(XPS)对其表面结构进行了表征。采用圆形传输线模型(CTLM)研究了不同表面处理后Au/CdMnTe接触的比接触电阻率(Rho(C))。原子力显微镜测量结果表明，化学机械抛光+化学机械抛光处理后表面超光滑，粗糙度为0.84 nm，MP、CP和化学机械抛光处理后的表面粗糙度分别为8.2 nm、5.1 nm和1.4 nm。XPS分析表明，Cp+CP和MP处理后的样品(Te+Te4+)/(Cd+Mn)比值分别为1.1和1.07，接近化学计量比，而CP和CMP处理后样品的(Te+Te4+)/(Cd+Mn)比值分别为2.00和1.40。化学机械抛光+化学机械抛光处理使Te~(4+)/(Te+Te~(4+))比值从化学机械抛光时的7%降至1%，表面几乎没有Te氧化物。用比接触电阻率(Rho(C))测量了Au/CdMnTe接触的欧姆特性。计算了Cp、Cp和Cp+Cp处理表面上Au/CdMnTe接触的Rho(C)值，分别为383、112和15Omega cm(2)。(C)2014爱思唯尔有限公司。保留所有权利。
The surface quality of CdMnTe crystal plays an important role in the performance of nuclear radiation detectors. In this paper, the surfaces of CdMnTe samples treated Mechanical Polishing (MP), Chemical Polishing (CP), Chemical-Mechanical Polishing (CMP), and CMP followed by CP treatment (CMP+CP) were investigated. The structural properties of CdMnTe surfaces were characterized by a High Resolution Scanning Electron Microscope (HRSEM), Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). The Circular Transmission Line Model (CTLM) was adopted to reveal the specific contact resistivity (rho(c)) of Au/CdMnTe contacts after various surface treatments. The AFM measurements shown an ultra-smooth surface was achieved after the CMP+CP treatment with the roughness value of 0.84 nm, and the surfaces by MP, CP and CMP were with the roughness of 8.2 nm, 5.1 nm and 1.4 nm, respectively. The XPS analysis indicated that the (Te+Te4+)/(Cd+Mn) ratios of the CdMnTe samples after the CMP+CP and MP treatment were 1.1 and 1.07 which are close to stoichiometric composition, while after the CP and CMP treatment were 2.00 and 1.40 which are enriched with Te. The CMP+CP treatment decreased the Te4+/(Te+Te4+) ratio from 7% in CMP to 1%, which reveals the surface with few Te oxides. The specific contact resistivity (rho(c)) was used to determine the ohmic characteristic of Au/CdMnTe contacts by the CFLM. calculated rho(c) values of Au/CdMnTe contacts on the CP, CMP and CMP+CP treated surfaces 383, 112 and 15 Omega cm(2), respectively. (C) 2014 Elsevier Ltd. All rights reserved.