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1.
测量了未掺杂半绝缘(SI)LECGaAs中总的、电中性的EL2及净受主浓度分布和碳分布。结果表明,总EL2浓度径向分布呈W形而不是均匀的,净受主浓度径向分布呈∧形或∩形而不是M形。电中性EL2的W形径向分布由总EL2浓度的W形径向分布决定,而不是由于净受主的不均匀分布。有些样品中净受主浓度远大于碳浓度.意味着这些样品中除碳外还存在高浓度的其它受主。 相似文献
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热处理改善未掺杂LEC GaAs中EL2分布均匀性机理的研究 总被引:2,自引:1,他引:1
杨瑞霞 《固体电子学研究与进展》1994,14(1):85-90
根据EL2分布的热处理行为和As沉淀分布特征的实验结果,讨论了As沉淀对EL2分布的影响和热处理改善EL2分布均匀性的机理。 相似文献
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The quenching of the photocurrent and photo-Hall effect of several undoped semi-insulating gallium arsenide samples has been
measured and compared with the deep-level photoluminescence spectra from neighboring samples. Samples that show either EL2
(0.68 eV) or ELO (0.63 eV) photoluminescence have distinctly different photocurrent quenching behaviors. EL2 samples show
a photocurrent decrease of several orders of magnitude, and a change fromn-type to p-type conduction during quenching at 80 K with 1.1 eV light. ELO samples show a reduction in photocurrent of less
than an order of magnitude with no change in the carrier type at this temperature. Photo-Hall effect experiments at 80 K indicate
that the conduction isn-type for the ELO samples, but changes fromn- to p-type during the quench for the EL2 samples. The temperature dependence of the quenching has also been studied. EL2
samples show little variation in the range 10-80 K, while ELO samples show significant quenching similar to EL2 after the
temperature is reduced below 70 K. These results indicate that defects other than EL2 can significantly affect photocurrent
quenching experiments. 相似文献
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比较了掺In和非掺杂LEC-GaAs晶体中的EL2缺陷,分析了掺In量的不同与热处理过程的不同对LEC-GaAs晶体中EL2缺陷的影响。 相似文献
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利用范德堡方法和光吸收方法研究了非掺杂半绝缘(SI)LECGaAs 中电参数与碳(C)浓度及EL2 浓度的关系。通过比较实验结果和理论计算结果发现,这种半绝缘晶体中除C外还存在其它受主在电补偿中起重要作用 相似文献
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A rigorous formulation of capacitance changes during trap filling processes is presented and used to accurately determine
the electron capture cross section of EL2 in GaAs at a particular temperature, 377K, in this case. The value, σn (377K) = 2.7 × 10−16 cm2, is compared with that predicted from the emission dependence. 相似文献
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M. S. Skolnickf M. R. Brozel L. J. Reed I. Grant D. J. Stirland R. M. Ware 《Journal of Electronic Materials》1984,13(1):107-125
The distribution of the dominant deep trap EL2 in 7.5cm diameter crystals of semi-insulating GaAs is studied by whole slice
infrared imaging. Very significant fluctuations in the neutral EL2 concentration ([EL2]ℴ) are observed, corresponding at most
to variations in [EL2]ℴ of up to 80%. The different sorts of fine structure, namely cell structure and bands of high infrared
absorption ("sheets" and “streamers”) lying in (110) planes running down the <001> growth directions, are described. 相似文献
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在建立的理论模型基础之上,定量地分析了EL2能级对GaAs MESFET夹断电压的影响,指出位于本征费米能级以下的EL2能级是影响GaAs MESFET夹断电压大小的主要因素,EL2能级对GaAs MESFET夹断电压的影响程度与EL2能给的缺陷密度呈线性关系。 相似文献
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Structural and infrared absorption properties of self-organized InGaAs/GaAs quantum dots multilayers
Q. D. Zhuang J. M. Li Y. P. Zeng L. Pan Y. H. Chen M. Y. Kong L. Y. Lin 《Journal of Electronic Materials》1999,28(5):503-505
Self-organized InGaAs/GaAs quantum dots (QDs) stacked multilayers have been prepared by solid source molecular beam epitaxy.
Cross-sectional transmission electron microscopy shows that the InGaAs QDs are nearly perfectly vertically aligned in the
growth direction [100]. The filtering effect on the QDs distribution is found to be the dominant mechanism leading to vertical
alignment and a highly uniform size distribution. Moreover, we observe a distinct infrared absorption from the sample in the
range of 8.6–10.7 μm. This indicates the potential of QDs multilayer structure for use as infrared photodetector. 相似文献
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我们采用EHT法计算了EL2缺陷模型的电子能级及其波函数,集团包含41个原子,用群论方法约化久期行列式。同时计算了该缺陷能级的光电离截面,计算结果与实验结果相符。 相似文献
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热处理和淬火的未掺杂半绝缘LEC GaAs的均匀性 总被引:2,自引:0,他引:2
对未掺杂原生LECSIGaAs单晶在500~1170℃温度范围进行了单步、两步和三步热处理及淬火,研究了这种热处理对EL2分布的影响,并检测了位错和As沉淀的变化。结果表明,650℃以上温度的热处理可以改善EL2分布均匀性,且在650~950℃温度范围的热处理中,EL2均匀性的改善与热处理后的降温速率无明显联系。此外,两步或三步热处理的样品中EL2分布甚至比单步热处理样品中更优。950℃以下的热处理和淬火对位错和As沉淀无明显影响。但是1170℃热处理井淬火后位错密度增加大约30%,As沉淀消失。对经1170℃淬火的样品再进行80O℃或950℃的热处理,As沉淀重新出现。EL2分布的变化可能与点缺陷、位错和As沉淀的相互作用有关。文中提出了这种相互作用的模型,利用该模型可解释不同条件热处理后EL2分布的变化。 相似文献
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张福贵 《电子科学学刊(英文版)》1989,6(2):184-188
A new method is applied to characterize the defects in GaAs material(e.g.the absorption ofEL2 centres).The method consists of transmitting a laser beam(λ=1.1-1.5μm)through the GaAs wa-fer of 4—8 mm thickness and 50 mm diameter.The image is received by the TOSHIBA 8844 cameraand entered into the DATASUD computer image processing system.This image is displayed on amonitor permitting to observe the inhomogeneity(like cross,cells and volutes)of theEL2 and dislocation defects.This paper will introduce a specific image processing software for GaAs materi-al,called ZHIMAG(ZHang IMAGe)and its application to GaAs wafer.The software can bealso applied to any other types of image processing. 相似文献
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G. Bremond N. Hizem G. Guillot M. Gavand A. Nouailhat W. Ulrici 《Journal of Electronic Materials》1989,18(3):391-397
The results of optical absorption and deel level transient spectroscopy on various V-doped GaAs materials (n type Bridgman, n and p type liquid encapsulated Czochralski,n andp type liquid phase epitaxy) are reported. It is definitively shown that the single acceptor state of isolated vanadium is
located atE
c
-0.14 eV and that no mid gap-level related to isolated vanadium which could explain same reported semi-insulating properties
of V-doped GaAs has been detected. From the analysis of the absolute photoionization cross section gs/sk
n
o of the above level it is shown that V2+ is in a low spin state in accordance with recent theoretical predictions. 相似文献
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The excitation photocapacitance measurements are performed on n-GaAs to obtain charge transition characteristics of EL2 defects in a full spectral region. It is shown that the threshold photon energy for EL2++ to EL2+ transition is changed as a function of the primary excitation photon energy. It is also shown that the Frank–Condon shifts (dFC) changed. It is considered that the lattice relaxation around the EL2 defect is affected by the deviation from the stoichiometric composition. 相似文献
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用1553nm飞秒光纤激光器触发半绝缘GaAs光电导开关的实验表明,当光电导开关处于3.33~10.3kV/cm的直流偏置电场并被脉冲宽度200fs且单脉冲能量0.2nJ的激光脉冲照射时,开关表现为线性工作模式,开关输出峰值电压为0.8mV.分析表明,开关对波长为1553nm触发激光脉冲表现出的弱光电导现象起因于半绝缘GaAs材料EL2深能级的作用. 相似文献
20.
Peculiar Photoconduction in Semi-Insulating GaAs Photoconductive Switch Triggered by 1064nm Laser Pulse 总被引:4,自引:2,他引:2
The peculiar photoconduction in semi-insulating GaAs photoconductive switch being triggered by 1064nm laser pulse is reported.The gap between two electrodes of the switch is 4mm.When it is triggered by laser pulse with energy of 0.8mJ and the pulse width of 5ns,and operated at biased electric field of 2.0 and 6.0kV/cm,both linear and nonlinear modes of the switch are observed respectively.Whereas the biased electric field adds to 9.5kV/cm,and the triggered laser is in range of 0.5~1.0mJ,the peculiar performed characteristic is observed:the switch gives a linear waveform firstly,and then after a delaytime of about 20~250ns,it outputs a nonlinear waveform again.The physical mechanism of this specific phenomenon is associated with the anti-sitedefects of semi-insulating GaAs and two-step-single-photon absorption.The delay time between linear waveform and nonlinear waveform is calculated,and the result matches the experiments. 相似文献