共查询到18条相似文献,搜索用时 55 毫秒
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报道了近年来昆明物理研究所在富碲水平推舟液相外延碲镉汞外延薄膜制备技术方面的进展。2019年以来,突破了?120 mm碲锌镉晶体定向生长技术,使碲锌镉衬底沉积相和夹杂相密度≤5×103 cm-2,位错腐蚀坑密度(EPD)≤4.0×104 cm-2,?120 mm(111)晶圆衬底的Zn组份分布极差≤0.36%。基于碲锌镉衬底技术的进步,液相外延碲镉汞薄膜的最大生长尺寸达到了70 mm×75 mm,薄膜位错腐蚀坑密度均值为5×104 cm-2,X射线双晶回摆曲线半峰宽(DCRC-FWHM)≤35 arcsec,部分可控制到25 arcsec以下;50 mm×60 mm尺寸长波碲镉汞薄膜的厚度极差≤±1.25 μm,室温截止波长极差≤±0.1 μm,中波碲镉汞薄膜相应指标分别为≤±1 μm、≤±0.05 μm。材料技术的进展促进了制冷型碲镉汞探测器产能提升和成本的降低,也支撑了高性能长波/甚长波探测器、高工作温度(HOT)探测器以及2048×2048、4096×4096等甚高分辨率高性能探测器的研制。 相似文献
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碲镉汞富碲垂直液相外延技术 总被引:1,自引:1,他引:0
研究了碲镉汞富碲垂直液相外延技术.在研究该关键技术的过程中,提出了一种方法以检查外延前(Hg1-xCdx)1-yTey母液的均匀性.并且,通过减小生长腔体中的自由空间,对气体的对流和汞回流进行了抑制,及通过改进工艺过程中的温度控制方式来应对因对流和汞回流而造成的生长温度不确定性.在解决上述关键技术后,实现了碲镉汞垂直液相外延工艺的稳定性,所外延的中波碲镉汞材料的组分可重复性做到了±0.005,厚度控制能力达到了±5μm ,40×30mm2外延材料的横向组分均匀性(相对均方差)小于1.3×10-3,同生长批次材料片与片之间的组分和厚度差异分别小于0.001和1μm.在10mm线度上,表面起伏小于1μm.经热处理后,中波汞空位p型材料在77K下具有较高的空穴迁移率.另外,和水平推舟技术相比,垂直碲镉汞液相外延在提供大批量和大面积相同性能材料方面具有明显的优势,这对于二代碲镉汞红外焦平面批生产技术和拼接型超大规模红外焦平面技术的发展都具有重要的意义. 相似文献
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碲镉汞外延用衬底材料的现状和发展 总被引:4,自引:4,他引:0
文章综合论述了碲镉汞外延用的衬底材料的现状,着重介绍了几种衬底材料CdTe、
Al2O3、GaAs、Ge、Si等的性能特点与各自的优缺点,评述了它们在碲镉汞外延中的使用情况,并对其未来的发展方向做出了预测。 相似文献
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为了研究液相外延碲镉汞薄膜表面缺陷形成机制,采用光刻工艺结合化学腐蚀方法在碲锌镉衬底表面实现了网格化,研究了碲锌镉近表面富碲沉积相与外延薄膜表面缺陷的关系.结果表明:衬底近表面富碲沉积相会导致碲镉汞薄膜表面孔洞、类针形凹陷坑缺陷以及三角形凹陷坑聚集区;在液相外延过程中,高温碲镉汞熔液与CdZnTe衬底间的回熔作用可以减少与富碲沉积相相关的表面缺陷,薄膜表面缺陷与衬底表面富碲沉积相的匹配度与回熔深度负相关;回熔过程以及富碲沉积相形态、深度影响HgCdTe薄膜表面缺陷形态和分布. 相似文献
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M. Reddy J. M. Peterson S. M. Johnson T. Vang J. A. Franklin E. A. Patten W. A. Radford J. W. Bangs D. D. Lofgreen 《Journal of Electronic Materials》2009,38(8):1764-1770
This paper presents the progress in the molecular beam epitaxy (MBE) growth of HgCdTe on large-area Si and CdZnTe substrates
at Raytheon Vision Systems. We report a very high-quality HgCdTe growth, for the first time, on an 8 cm × 8 cm CdZnTe substrate.
This paper also describes the excellent HgCdTe growth repeatability on multiple 7 cm × 7 cm CdZnTe substrates. In order to
study the percentage wafer area yield and its consistency from run to run, small lots of dual-band long-wave infrared/long-wave
infrared triple-layer heterojunction (TLHJ) layers on 5 cm × 5 cm CdZnTe substrates and single-color double-layer heterojunction
(DLHJ) layers on 6-inch Si substrates were grown and tested for cutoff wavelength uniformity and micro- and macrovoid defect
density and uniformity. The results show that the entire lot of 12 DLHJ-HgCdTe layers on 6-inch Si wafers meet the testing
criterion of cutoff wavelength within the range 4.76 ± 0.1 μm at 130 K and micro- and macrovoid defect density of ≤50 cm−2 and 5 cm−2, respectively. Likewise, five out of six dual-band TLHJ-HgCdTe layers on 5 cm × 5 cm CdZnTe substrates meet the testing criterion
of cutoff wavelength within the range 6.3 ± 0.1 μm at 300 K and micro- and macrovoid defect density of ≤2000 cm−2 and 500 cm−2, respectively, on the entire wafer area. Overall we have found that scaling our HgCdTe MBE process to a 10-inch MBE system
has provided significant benefits in terms of both wafer uniformity and quality. 相似文献
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S. M. Johnson J. A. Vigil J. B. James C. A. Cockrum W. H. Konkel M. H. Kalisher R. F. Risser T. Tung W. J. Hamilton W. L. Ahlgren J. M. Myrosznyk 《Journal of Electronic Materials》1993,22(8):835-842
Large-area HgCdTe 480×640 thermal-expansion-matched hybrid focal plane arrays were achieved by substituting metalorganic chemical
vapor deposition (MOCVD)-grown CdZnTe/GaAs/Si alternative substrate in place of bulk CdZnTe substrates for the growth of HgCdTe
p-on-n double-layer heterojunctions by controllably-doped mercury-melt liquid phase epitaxy (LPE). (100) CdZnTe was grown
by MOCVD on GaAs/Si using a vertical-flow high-speed rotating disk reactor which incorporates up to three two-inch diameter
substrates. Layers having specular surface morphology, good crystalline structure, and surface macro defect densities <50
cm−2 are routinely achieved and both the composition uniformity and run-to-run reproducibility were very good. As the composition
of the CdZnTe layers increases, the x-ray full width at half maximum (FWHM) increases; this is a characteristic of CdZnTe
grown by VPE techniques and is apparently associated with phase separation. Despite a broader x-ray FWHM for the fernary CdZnTe,
the FWHM of HgCdTe grown by LPE on these substrates decreases, particularly for [ZnTe] compositions near the lattice matching
condition to HgCdTe. An additional benefit of the ternary CdZnTe is an improved surface morphology of the HgCdTe layers. Using
these silicon-based substrates, we have demonstrated 78K high-performance LWIR HgCdTe 480×640 arrays and find that their performance
is comparable to similar arrays fabricated on bulk CdZnTe substrates for temperatures exceeding approximately 78K. The performance
at lower temperatures is apparently limited by the dislocation density which is typically in the low-mid 106 cm−2 range for these heteroepitaxial materials. 相似文献
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Lattice mismatch induced morphological features and strain in HgCdTe epilayers on CdZnTe substrates 总被引:1,自引:0,他引:1
David R. Rhiger Sanghamitra Sen Jeffrey M. Peterson Hua Chung Michael Dudley 《Journal of Electronic Materials》1997,26(6):515-523
HgCdTe epilayers on CdZnTe substrates can exhibit a cross-hatch pattern of periodically varying strain and surface undulations
as revealed by x-ray topography, and in some cases by Nomarski optical microscopy. On { 111 } oriented material, the pattern
appears as three sets of parallel lines in the 〈 110 〉 slip directions (60° apart). To investigate this phenomenon and its
impact on photovoltaic device performance, we have characterized several liquid phase epitaxy (LPE)-grown HgCdTe epilayer
samples by means of Lang x-ray reflection topography, synchrotron white beam x-ray topography (SWBXT), etch pit density, and
other techniques. The cross hatching generally shows a correlation with the ZnTe mole fraction of the substrate. In particular,
the pattern is likely to appear when the natural lattice parameter of the layer at room temperature is slightly larger or
smaller than that of the substrate in the same region. We also find the corresponding pattern in { 211 } oriented layers grown
by MBE. Although substantial compositional interdiffusion occurs at the layer/substrate interface during LPE growth at around
500°C, this is not a necessary condition for the cross-hatch pattern, as demonstrated by the occurrence of the pattern in
MBE material grown at less than 200°C. In terms of device performance, the pattern is manifested as lines of diodes in an
array having greater leakage than their neighbors. In addition to these results, we have investigated other anomalies, by
means of SWBXT applied to large-area diodes that have been electrically tested. A novel technique called absorption edge contour
mapping, using synchrotron white beam x-rays with a molybdenum filter, was applied to reveal the longer range lattice strain. 相似文献