共查询到19条相似文献,搜索用时 171 毫秒
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碲锌镉晶体中存在着各种典型晶体缺陷,其缺陷研究一直倍受关注,X射线衍射形貌术是一种非破坏性地研究晶体材料结构完整性、均匀性的有效方法.采用反射式X射线衍射形貌术对碲锌镉衬底的质量进行了研究,并将衬底的X射线衍射形貌与Everson腐蚀形貌进行了对比分析,碲锌镉衬底的X射线衍射形貌主要有六种特征类型,分别对应不同的晶体结构或缺陷,包括均匀结构、镶嵌结构、孪晶、小角晶界、夹杂、表面划伤,对上述特征类型进行了详细的分析.目前,衬底的X射线衍射形貌主要以均匀结构类型为主,划伤和镶嵌结构缺陷基本已消除,存在的晶体缺陷主要以小角晶界为主.通过对比分析碲锌镉衬底和液相外延碲镉汞薄膜的X射线衍射形貌,发现小角晶界等晶体结构缺陷会延伸到外延层上,碲锌镉衬底质量会直接影响碲镉汞外延层的质量,晶体结构完整的衬底是制备高质量碲镉汞外延材料的基础. 相似文献
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主要报道了用于提高液相外延(Liquid Phase Epitaxy, LPE)长波碲镉汞薄膜质量的碲锌镉衬底筛选方法研究。通过对碲锌镉衬底的锌组分、红外透过率、沉淀/夹杂、位错密度、X射线形貌像和X射线衍射半峰宽等参数进行全面测试以及对外延后碲镉汞薄膜的X射线形貌像和X射线衍射半峰宽进行测试评估,发现目前X射线形貌像和锌组分是影响LPE长波碲镉汞薄膜用碲锌镉衬底的重要参数。结果表明,锌组分处于4.2%~4.8%之间、形貌像衍射强度高且均匀性好是长波碲镉汞薄膜外延用衬底的理想选择。 相似文献
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红外光热吸收效应作为一种无损伤非接触的检测技术,已经被广泛用于硅等半导体材料中的微缺陷表征分析.采用光热吸收技术对碲锌镉晶体中的缺陷进行扫描成像分析时发现了一种连续性的光貌相条纹,并对这些条纹的形成机理进行了研究.研究表明碲锌镉晶体中的这种连续性条纹源自于光热测试系统中入射光的干涉,这种干涉和入射光参数、测试样品的厚度、禁带宽度以及热导率等材料特性密切相关.最后,实验通过优化红外光热吸收测量系统获得了碲锌镉材料中的微缺陷结构及其在样品深度方向的三维分布图像. 相似文献
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《碲汞和碲锌镉晶体的显微图集》 《红外技术》2001,23(1)
《碲汞和碲锌镉晶体的显微图集》(以下简称《图集》)系由中国兵器工业总公司国防预研基金资助完成的研究项目,已通过总公司组织的技术鉴定,并获得部级科技进步三等奖。 通过X射线衍射术(包括同步辐射)、电子通道术、光学和电子金相显微术等多种技术,对探测器材料碲镉汞(Hg1-x)CdxTe)及其探测器芯片和碲锌镉(Cd1-yZnyTe)进行较深入细致的研究后制成了本《图集》。它包括两部分,即显微组织图(基础图和结构缺陷图)和探测器芯片的X射线形貌相图。基础图指具有特定晶体学取向的近完整晶体的X射线劳厄相和扫描谱及电子通道花样等;缺陷图为具有特定取向和偏离特定取向晶面上的位错和亚晶界图,孪晶和晶图以及其它缺陷和显微硬度试验图等。各图片都配有试样制备等相应注解。 《图集》有精选的644幅图片,以《红外技术》增刊公开的出版发行。该《图集》内文为进口128克双面铜版纸,图片电子分色,封面为硬壳精装烫金色,16开本,约200页,每本收工本费180元。欢迎订购。 相似文献
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研究了液相外延生长条件对碲镉汞薄膜材料组分梯度的影响,建立了指导液相外延生长的理论模型。通过改变水平推舟液相外延工艺的汞损失速率,生长出具有正组分梯度的碲镉汞薄膜材料。针对这种特定条件下生长的碲镉汞外延薄膜,通过腐蚀减薄光谱测试与二次离子质谱测试证实了材料具有正组分梯度结构。与传统方法生长的具有负组分梯度的碲镉汞薄膜相比,这种薄膜材料具有相近的表面形貌与红外透射光谱曲线;且具有较高的晶体质量,其X射线衍射双晶摇摆曲线半峰宽达到28.8 arcsec。 相似文献
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G. A. Carini G. S. Camarda Z. Zhong D. P. Siddons A. E. Bolotnikov G. W. Wright B. Barber C. Arnone R. B. James 《Journal of Electronic Materials》2005,34(6):804-810
High-energy transmission x-ray diffraction techniques have been applied to investigate the crystal quality of CdZnTe (CZT).
CdZnTe has shown excellent performance in hard x-ray and gamma detection; unfortunately, bulk nonuniformities still limit
spectroscopic properties of CZT detectors. Collimated high-energy x-rays, produced by a superconducting wiggler at the National
Synchrotron Light Source’s X17B1 beamline, allow for a nondestructive characterization of thick CZT samples (2–3 mm). In order
to have complete information about the defect distribution and strains in the crystals, two series of experiments have been
performed. First, a monochromatic 67 keV x-ray beam with the size of 300×300 μm2 was used to measure the rocking curves of CZT crystals supplied by different material growers. A raster scan of a few square
centimeter area allowed us to measure the full-width at half-maximum (FWHM) and shift in the peak position across the crystal.
The rocking curve peak position and its FWHM can be correlated with local stoichiometry variations and other local defects.
Typically, the FWHM values ranging from 8.3 arcsec to 14.7 arcsec were measured with the best crystal used in these measurements.
Second, transmission white beam x-ray topography (WBXT) was performed by using a 22 mm×200 μm beam in the energy range of 50 keV to 200 keV. These types of measurements allowed for large area, high-resolution (50 μm) scans of the samples. Usually, this technique is used to visualize growth and process-induced defects, such as dislocations,
twins, domains, inclusions, etc. the difference in contrast shows different parts of the crystal that could not be shown otherwise.
In topography, good contrast is indicative of a high quality of the sample, while blurred gray shows the presence of defects.
Correlation with other techniques (e.g., infrared (IR) mapping and gamma mapping) was also attempted. Our characterization
techniques, which use highly penetrating x-rays, are valid for in-situ measurements, even after electrical contacts have been
formed on the crystal in a working device. Thus, these studies may lead to understanding the effects of the defects on the
device performance and ultimately to improving the quality of CZT material required for device fabrication. It is important
to study crystals from different ingot positions (bottom, center, and top); consequently, more systematic studies involving
scans from center to border are planned. 相似文献
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文章报道了采用液相外延方法,在碲锌镉衬底上进行碲锌镉薄膜缓冲层生长的情况,并且采用X光双晶衍射仪、X光形貌仪、红外傅里叶光谱仪、二次离子质谱仪等手段对碲锌镉薄膜进行了表征,碲锌镉薄膜具有较好地组分及均匀性,晶体结构质量也较好。采用碲锌镉缓冲结构生长了碲镉汞液相外延片,其碲锌镉与碲镉汞薄膜界面附近的杂质得到了有效的控制。 相似文献
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文章采用富Te水平推舟液相外延工艺在CdZnTe衬底上生长了HgCdTe外延薄膜。研究了外延薄膜/衬底晶格失配度、X光衍射貌相、红外焦平面器件探测率三者之间的关系。对于HgCdTe外延层的X光衍射貌相我们将其大致分为五类,分别是Crosshatch貌相、混合貌相、均匀背景貌相、Mosaic貌相以及由衬底质量问题引起的沟壑状貌相,采用Crosshatch貌相和混合貌相材料所制备的红外焦平面器件,平均来说其探测率(D*)较高。X射线双轴衍射的实验结果表明,当外延层与衬底的晶格失配度为~0.03%时,外延层会呈现明显的Crosshatch貌相;而当失配度减小时,会逐渐呈现出混合貌相、均匀背景貌相、直至失配度为负值时呈现Mosaic貌相。因此,对于特定截止波长的HgCdTe焦平面器件,可以通过控制HgCdTe/CdZnTe之间的失配,生长出符合我们要求的貌相的碲镉汞外延材料,从而来提高焦平面器件的性能。 相似文献
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L. A. Almeida S. Hirsch M. Martinka P. R. Boyd J. H. Dinan 《Journal of Electronic Materials》2001,30(6):608-610
We report on continuing efforts to develop a reproducible process for molecular beam epitaxy of CdZnTe on three-inch, (211)
Si wafers. Through a systematic study of growth parameters, we have significantly improved the crystalline quality and have
reduced the density of typical surface defects. Lower substrate growth temperatures (∼250–280°C) and higher CdZnTe growth
rates improved the surface morphology of the epilayers by reducing the density of triangular surface defects. Cyclic thermal
annealing was found to reduce the dislocation density. Epilayers were characterized using Nomarski microscopy, scanning electron
microscopy, x-ray diffraction, defect-decoration etching, and by their use as substrates for HgCdTe epitaxy. 相似文献
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