共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
3.
4.
CdZnTe晶体生长所取得的进展,使得人们有可能制备出供γ射线光谱技术使用在室温下工作并具有良好能量分辨率的探测器。 相似文献
5.
6.
7.
8.
碲锌镉晶体的范性形变研究 总被引:2,自引:1,他引:1
从经典的晶体范体形变的理论模型和面心立方闪锌矿结构晶体所具有的滑移特性出发,对碲锌镉晶体经特定化学试剂侵蚀后在(111)和(1-↑1-↑1-↑)面上出现的不同形貌蚀坑的形成机理进行了探讨,提出了碲锌镉晶体中存在多系滑移,从而阐明了不同极性面上蚀坑的成因。 相似文献
9.
该研究以提高液相外延碲镉汞材料的质量为出发点,研究液相外延生长过程中碲锌镉衬底受到高温汞蒸气影响后的变化情况,并利用光学显微镜、白光干涉仪、能谱仪等分析测试手段对碲锌镉衬底表面进行分析.研究结果表明,液相外延生长过程中,高温汞蒸气对碲锌镉衬底中表面沉淀物尺寸无明显影响,但在衬底表面发现两种类型的腐蚀点,一种是尺寸为25μm左右的较大腐蚀点,分布较均匀;另一种是尺寸为7μm左右的圆形腐蚀点,分布不均匀.衬底经过液相外延薄膜成核生长前的温度变化过程以及高温Hg蒸气的作用,碲锌镉衬底表面形貌呈鱼鳞状,粗糙度增大了50%以上. 相似文献
10.
大面积、高质量碲锌镉单晶是制备碲镉汞红外焦平面器件的理想衬底材料,而腐蚀法是常用的揭示碲锌镉晶体缺陷和评价晶体质量的方法之一。对碲锌镉晶体常用的Nakagawa、Everson、EAg1和EAg2四种腐蚀剂在碲锌镉材料(111)晶面上的腐蚀坑坑形进行了研究,结果发现,EAg2腐蚀剂在(111)B面上的腐蚀坑为平底坑,Everson腐蚀剂在 (111)B面上产生的腐蚀坑包括平底坑和带有不同倾斜方向坑底的三角锥形坑,进一步的研究还表明,三角锥形坑并未沿着坑底的倾斜方向向下延伸。实验中也首次观察到了EAg腐蚀剂的黑白平底坑。对常用腐蚀剂的坑形特性研究,将有助于更好地利用腐蚀剂开展碲锌镉材料缺陷研究和晶体质量评价工作。 相似文献
11.
In this paper, we review theoretical and experimental studies on the infrared attenuation spectrum between 400 and 4000 cm−1, which is principally due to the free carrier absorption (FCA). The free carrier absorption is possible by means of inter-conduction band transitions which occur in n-CdZnTe, or by means of inter-valence band transitions which occur in p-CdZnTe. Based on the power law fit results of absorption spectra determined by FCA characteristics, we present an optical measurement technique, which can help us to determine the conduction type of CdZnTe in another way. 相似文献
12.
Infrared absorption behavior in CdZnTe substrates 总被引:4,自引:0,他引:4
S. Sen D. R. Rhiger C. R. Curtis M. H. Kalisher H. L. Hettich M. C. Currie 《Journal of Electronic Materials》2001,30(6):611-618
Infrared (IR) optical transmission measurements of polished CdZnTe wafers can provide useful information about excess impurities,
stoichiometry, and inhomogeneities (precipitates and inclusions). We have investigated the IR transmission behavior of Cd0.96Zn0.04Te between 8 m and 20 m at room temperature. The measurements were made before and after thermal treatments involving control
of the Cd and Zn overpressures, which served to minimize the Cd (cation) vacancy population. Our results support the polar
optical phonon scattering theory of Jensen, according to which the absorption in donor dominated CdZnTe varies asm with m=3. For material dominated by acceptors, we show that the theoretical absorption by inter-valence band transitions
can be approximated by a similar power law with exponent m=1, and that Cd-vacancy dominated wafers are in reasonable agreement
with this. We find some wafers in which the asgrown condition exhibits partial compensation of impurity donors by Cd vacancy
acceptors, and demonstrate removal of the compensation by annealing to fill the vacancies. In a separate group of wafers,
we find that an observed increase in absorption occurring during growth of a HgCdTe layer by liquid phase epitaxy can be explained
in terms of an increase in Cd vacancies caused by diffusion of Cd to Te precipitates. This effect can be reversed by annealing
in Cd−Zn vapor, which fills vacancies and eliminates some precipitates. Impurity concentrations were measured by glow discharge
mass spectrometry (GDMS). 相似文献
13.
R. Sudharsanan T. Parodos A. Ruzin Y. Nemirovsky N. H. Karam 《Journal of Electronic Materials》1996,25(8):1318-1322
In this paper, we report on the design, fabrication, and performance of the first CdZnTe Schottky photodiode arrays for radiation
detection. High pressure Bridgman-grown CdZnTe substrates with bulk resistivities in the range 108 to 1010 ohm-cm were used. CdZnTe Schottky photodiodes were formed with In and Ti/Au contacts. Diode arrays with pixel sizes from
1000 × 1000 (im to 100 × 100 urn were fabricated. The diode’s I-V characteristics exhibited low leakage current and high bulk
resistivity; leakage current decreased as diode pixel size was reduced. Response of these detector arrays to high energy photons
was uniform and their energy resolution improved with smaller pixel size. 相似文献
14.
15.
16.
Direct growth of CdZnTe/Si substrates for large-area HgCdTe infrared focal plane arrays 总被引:1,自引:0,他引:1
S. M. Johnson T. J. de Lyon C. A. Cockrum W. J. Hamilton T. Tung F. I. Gesswein B. A. Baumgratz L. M. Ruzicka O. K. Wu J. A. Roth 《Journal of Electronic Materials》1995,24(5):467-473
Direct epitaxial growth of high-quality 100lCdZnTe on 3 inch diameter vicinal {100}Si substrates has been achieved using molecular
beam epitaxy (MBE); a ZnTe initial layer was used to maintain the {100} Si substrate orientation. The properties of these
substrates and associated HgCdTe layers grown by liquid phase epitaxy (LPE) and subsequently processed long wavelength infrared
(LWIR) detectors were compared directly with our related efforts using CdZnTe/ GaAs/Si substrates grown by metalorganic chemical
vapor deposition (MOCVD). The MBE-grown CdZnTe layers are highly specular and have both excellent thickness and compositional
uniformity. The x-ray full-width at half-maximum (FWHM) of the MBE-grown CdZnTe/Si increases with composition, which is a
characteristic of CdZnTe grown by vapor phase epitaxy, and is essentially equivalent to our results obtained on CdZnTe/GaAs/Si.
As we have previously observed, the x-ray FWHM of LPE-grown HgCdTe decreases, particularly for CdZnTe compositions near the
lattice matching condition to HgCdTe; so far the best value we have achieved is 54 arc-s. Using these MBE-grown substrates,
we have fabricated the first high-performance LWIR HgCdTe detectors and 256 x 256 arrays using substrates consisting of CdZnTe
grown directly on Si without the use of an intermediate GaAs buffer layer. We find first that there is no significant difference
between arrays fabricated on either CdZnTe/Si or CdZnTe/GaAs/Si and second that the results on these Si-based substrates are
comparable with results on bulk CdZnTe substrates at 78K. Further improvements in detector performance on Si-based substrates
require a decrease in the dislocation density. 相似文献
17.
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
18.
19.
Robert Furstenberg Michael R. Papantonakis C.A. Kendziora 《Journal of Electronic Materials》2009,38(8):1533-1538
We report an infrared photo-thermal excitation imaging and spectroscopy study of CdTe and CdZnTe substrates as well as HgCdTe/CdZnTe
and HgCdTe/Si epilayers. The applicability, advantages, and limitations of the technique as a tool for both ex situ and in situ monitoring of bandgap, thickness, and growth temperature are discussed. We show that photo-thermal imaging allows for direct
visual imaging of the bandgap region of CdTe and CdZnTe substrates. We also show that photo-thermal spectroscopy can provide
epilayer thickness information independent of the dielectric function. The method is orthogonal to existing optical characterization
techniques and could be combined with them for improved accuracy. 相似文献
20.
采用傅里叶变换红外光谱仪测试了性能各异的多个CdZnTe晶片的红外透过率.研究表明,红外透过率的大小可以定性反映CdZnTe晶片的性能:红外透过率越高的晶片,其成分偏离越小,位错密度越低,电阻率越高.根据红外透过率大小随着波数的变化,红外透过率图谱可以分为4种,每一种图谱对应着具有不同性能的CdZnTe晶片,从晶片对红外光的吸收机理出发,对实验结果进行了初步分析。 相似文献