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1.
报道了激光束诱导电流(LBIC)在碲镉汞(HgCdTe)红外双色探测器工艺检测中的应用.通过LBIC测试,发现p型HgCdTe材料由B+离子注入损伤形成的n区面积大于其注入面积,并获得n区横向的精确分布.同时,运用LBIC,获得了p型HgCdTe材料因不同能量的等离子体干法刻蚀诱导的刻蚀台面侧壁工艺损伤形成的n区横向分布,并得到了n区横向宽度与等离子体能量的关系. 相似文献
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对用液相外延(Liquid Phase Epitaxy,LPE)方法生长的碲镉汞(HgCdTe)材料进行了闭管富汞热处理,并研究了不同的热处理时间和热处理温度对其电学性能的影响。通过对HgCdTe材料进行富汞热处理可以有效降低材料内的缺陷尺寸、密度以及位错密度,并可完成材料由p型到n型的转变。工艺中,低温热处理对HgCdTe材料的电学性能有较大影响。研究发现,随着低温热处理时间的持续增加,HgCdTe材料的载流子浓度会明显增加。而当低温热处理温度在210℃~250℃范围内变化时,保持低温热处理时间不变,热处理后HgCdTe材料的载流子浓度会在一定范围内波动(无明显变化)。通过对HgCdTe器件进行I--V曲线测试以及最终的组件测试发现,热处理后载流子浓度在1×1013~1×1014 cm-3范围内的HgCdTe芯片具有很好的测试结果。 相似文献
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用热力学原理探讨了Hg-Cd-Te固气两相平衡体系中材料参数和系统状态参数间的相互关系,给出了定量描述这些相互关系的理认计算公式和计算方法,通过对现有热力学常数的分析和评价,得到了计算所需的热力学常数以及和组分相关的经验公式.计算结果揭示了不同状态下HgCdTe材料中汞空位及和其它点阵缺陷比较的情况.计算结果也给出了汞空位浓度为(5~10)×1015cm-3HgCdTe材料的P-T相图,这为红外焦平面器件所需的弱P型HgCdTe材料热处理工艺从理论上提供了参考依据.通过计算三相平衡线上空位浓度的分布,对汞空位在不同生长工艺的情况也有了进一步的 相似文献
6.
从微观理论对P型HgCdTe离子刻蚀成结的过程、机理进行了分析,提出HgCdTe环孔P-N结的汞原子扩散-补偿模型、P-N结的汞原子扩散-补偿-剩余施主杂质模型,提出并讨论了离子刻蚀技术形成环孔型P-N结和平面型P-N结的汞原子扩散激活能、扩散汞原子总量、扩散范围、扩散系数、有效汞原子系数等关键物理参数与工艺参数. 相似文献
7.
对液相外延方法(LPE)生长的碲镉汞(HgCdTe)材料进行了闭管富汞热处理,并研究了不同的热处理时间和热处理温度对碲镉汞材料电学性能的影响。HgCdTe材料经过富汞热处理后可以有效降低材料内的缺陷尺寸和密度。该方法不仅可以降低材料内的位错密度,而且还可以完成材料P型到N型的转变。工艺中的低温热处理对HgCdTe材料的电学性能有较大影响。研究发现,随着低温热处理时间的持续增加,HgCdTe材料的载流子浓度会明显增加。而当低温热处理温度在210℃~250℃范围内变化时,若保持低温热处理时间不变,则热处理后HgCdTe材料的载流子浓度在一定范围内波动,且无明显变化。通过对HgCdTe器件进行I-V曲线测试以及最终的组件测试,发现热处理后载流子浓度在1E13~1E14cm-3范围内的HgCdTe芯片就可以得到很好的测试结果。 相似文献
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碲镉汞(HgCdTe)线性雪崩焦平面因其相对低的过剩噪声、较小的工作电压、线性可调等优点,得到了广泛关注。基于电子雪崩中波HgCdTe PIN二极管结构,开展暗电流模型和Okuto-Crowell增益模型仿真。通过改变器件材料结构参数模拟不同电压下的暗电流和增益特性。计算讨论了不同I区(本征区)厚度和载流子浓度对器件暗电流和增益的影响。结果表明结区峰值场强的变化会导致直接隧穿(BBT)电流产生率数量级上的剧烈变化;增加I区厚度和降低I区掺杂浓度可有效抑制BBT电流;增益随场强的变化趋势与BBT电流随场强的变化趋势一致;因此抑制BBT电流的措施会造成增益性能的下降,需要优化参数以获得最佳性能。综合考虑暗电流和增益性能,I区的厚度应不小于3μm,I区浓度需控制在5×1014cm-3以下。单元中波APD的增益实验结果与仿真数据较好地吻合,表明了理论模型的正确性。 相似文献
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《红外与毫米波学报》2020,(1)
碲镉汞(HgCdTe)线性雪崩焦平面因其相对低的过剩噪声、较小的工作电压、线性可调等优点,得到了广泛关注。基于电子雪崩中波HgCdTe PIN二极管结构,开展暗电流模型和Okuto-Crowell增益模型仿真。通过改变器件材料结构参数模拟不同电压下的暗电流和增益特性。计算讨论了不同I区(本征区)厚度和载流子浓度对器件暗电流和增益的影响。结果表明结区峰值场强的变化会导致直接隧穿(BBT)电流产生率数量级上的剧烈变化;增加I区厚度和降低I区掺杂浓度可有效抑制BBT电流;增益随场强的变化趋势与BBT电流随场强的变化趋势一致;因此抑制BBT电流的措施会造成增益性能的下降,需要优化参数以获得最佳性能。综合考虑暗电流和增益性能,I区的厚度应不小于3μm,I区浓度需控制在5×10~(14)cm~(-3)以下。单元中波APD的增益实验结果与仿真数据较好地吻合,表明了理论模型的正确性。 相似文献
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报道了液氮温度下激光束诱导电流(LBIC)和I-V测试两种在HgCdTe器件中pn结结区扩展的表征方法.通过LBIC和I-V测试,发现了p型HgCdTe材料中由B+离子注入成结和干法刻蚀成结对材料造成的损伤使得有效结区范围大于注入和刻蚀面积,并获得n区横向扩展.同时,通过对比,相互印证两种方法得到的测试结果一致. 相似文献
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D. Chandra H. F. Schaake F. Aqariden T. Teherani M. A. Kinch P. D. Dreiske D. F. Weirauch H. D. Shih 《Journal of Electronic Materials》2006,35(6):1470-1473
Exposure to specific damage introduced by either ion implantation or ion milling converts p-type short wavelength infrared
(SWIR) HgCdTe to n-type in a manner similar to the conversions in medium wavelength infrared (MWIR) or long wavelength infrared
(LWIR) mercury cadmium telluride. However, the depth of conversion for SWIR Hg1−xCdxTe, with x=0.48, is approximately 300% smaller when compared to the depth of conversion for MWIR HgCdTe for an identical degree
of ion milling. The depth of conversion, or the n/p junction depth, tracks linearly the extent of surface removals by ion
milling when the metal vacancy concentration is held invariant. These results can be correlated to the interaction between
metal vacancies and a product of the lattice damage process resulting from ion milling. The observation of a linear dependence
of this depth on the degree or time of ion milling rules out the existence of a diffusive barrier in the transfer of this
product for both MWIR and SWIR HgCdTe. 相似文献
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A model is presented which describes the motion of and interactions among some of the native point defects and foreign impurities
in Hg1-xCdxTe. Semi-quantitative simulations of typical process problems are performed for cases where only Hg interstitials, Hg vacancies,
and cation impurities are important. Results for the formation of n-on-p junctions by the Hg anneal of high vacancy concentration
material, indicate that junction depths may be a significant function of the n-type dopant concentration. For the case where
low vacancy, n-type material is annealed in a Hg-poor ambient, simulation results confirm the difficulty in forming a high
quality, well-defined p-on-n junction. This difficulty arises because of the generation of Hg vacancy/interstitial pairs throughout
the bulk during most of the process. It is demonstrated that impurity gettering can be described by our modeling approach.
All simulation results attempted to date are consistent with the available experimental data. 相似文献
14.
S. Barton D. Dutton P. Capper C. L. Jones N. Metcalfe 《Journal of Electronic Materials》1995,24(11):1759-1764
The performance of infrared detectors made from CdxHg1-xTe (CMT) is related to the lifetime of minority carriers in the material. Both photoconductive and photovoltaic devices require
long lifetimes for high performance. This paper compares lifetime measurements on epitaxially grown CMT layers which have
been isothermally annealed to minimize the vacancy concentration and are n-type due to native defects, residual impurities,
or deliberately added dopants. Layers grown by liquid phase epitaxy (LPE), metalorganic vapor phase epitaxy (MOVPE), and molecular
beam epitaxy (MBE) have been considered, in all cases the same measurement system was used under the same low injection conditions.
All layers were of compositions required for operation in the 8 to 14 μm wavelength range. Comparisons have been made between
undoped and indium doped LPE layers and undoped and iodine doped MOVPE layers. It was hoped that a deliberately introduced
donor impurity would give better control of the n-type properties. The effect of passivation on the measurement of lifetime
has also been considered, the results showing that a surface with a native oxide is required to obtain the true bulk lifetime
as has been seen previously for bulk material. 相似文献
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A Hall profiling technique in which measurements are made at 77K as a function of magnetic field (0.01–1T) and layer thickness
(by chemical thinning) has been developed for the characterization of Hg1−xCdxTe epitaxial layers. The technique has been applied to undoped and lightly In doped MOVPE interdiffusion multilayer process
(IMP) layers grown on (100) GaAs and CdTe with x values between 0.19 and 0.30 in order to investigate the parameters controlling
the electrical homogeneity. Results show unpassivated layers with x>0.25 are uniformly p-type with 77K hole concentrations
consistent with Hg vacancy concentrations for the growth conditions while layers with x<0.25 are anomalous, being either inhomogeneous
or uniformly n-type depending on x. The inhomogeneous layers are mainly n on p layer structures, in which the junction depth,
Xj, but not the carrier concentration is found to be a function of x and can be comparable to layer thickness at x=0.20. Carrier
levels in the n and p-type regions are consistent with the net background impurity donor and Hg vacancy concentrations respectively,
suggesting that the n-type properties occur through post growth Hg in-diffusion filling in the vacancies. This model was partly
confirmed by capping layers with CdTe, which significantly reduced the extent of the n-type region, and by ex-situ annealing
experiments to simulate the inhomogeneity. Results show the low temperature process responsible for the type conversion in
MOVPE CMT is highly x dependent, suggesting a variation in the electrical “Hg diffusion coefficient” of over an order of magnitude
between 0.20 and 0.30 at 200°C. Carrier and mobility profiles of both as-grown and annealed n-p structures are abrupt and
consistent with an interstitial Hg diffusion mechanism. 相似文献
16.
F. Gemain I.C. Robin S. Brochen M. De Vita O. Gravrand A. Lusson 《Journal of Electronic Materials》2012,41(10):2867-2873
Correlations between photoluminescence and temperature-dependent Hall measurements were carried out on unintentionally doped HgCdTe epilayers with cadmium composition of 32.7%. These films were grown by liquid-phase epitaxy and post-annealed under different conditions as follows: a p-type annealing was used to control the mercury vacancy concentration, and an n-type annealing under saturated mercury atmosphere was used to fill the mercury vacancies. Comparison of the results obtained by these two characterization techniques allowed us to identify the two acceptor energy levels of the mercury vacancy. Moreover, the “U-negativity” of the vacancy was evidenced: the ionized state V? is stabilized under the neutral state V0 by the dominance of the Jahn–Teller effect over Coulombic repulsion. Finally, three epilayers with different cadmium compositions were also characterized to complete this study. 相似文献
17.
Guiying Shen Youwen Zhao Yongbiao Bai Jingming Liu Hui Xie Zhiyuan Dong Jun Yang Ding Yu 《半导体学报》2019,40(4):13-16
Lightly Te-doped GaSb samples grown by the liquid encapsulated Czochralski(LEC) method have been studied by Hall measurements and low-temperature PL spectroscopy. The results suggest that acceptor-related antisite is the dominant defect in n-type GaSb with low Te-doping concentration. As the Te concentration increases, gallium vacancy related defects become the main acceptor. A new band of around 665 meV is observed in the GaSb sample with the lowest Te-doping concentration. The variation of the acceptor defects and their influence on the electronic and optical property on the n-GaSb single crystal are discussed based on the results. 相似文献
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C. L. Chang K. Mahalingam N. Otsuka M. R. Melloch J. M. Woodall 《Journal of Electronic Materials》1993,22(12):1413-1416
Precipitation processes in the p-type, n-type, and intrinsic GaAs layers grown by molecular beam epitaxy at a low temperature
were studied by transmission electron microscopy. The average spacing, average diameter, and volume fraction of precipitates
were measured as a function of the annealing time for the annealing temperature of 700°C. Volume fractions of precipitates
are nearly constant in each layer over the period of annealing, implying that the precipitation process has reached the coarsening
stage in the annealing times used in the study. The volume fraction of precipitates in the n-type layer is about a half of
those in the p-type and intrinsic layers, suggesting that the incorporation rate of excess As into the n-type layer during
the growth is lower than those into the p-type and intrinsic layers. Despite a large difference of amounts of excess As in
as-grown n-type, p-type, and intrinsic layers, the average spacings and, hence, number densities of precipitates in three
layers are nearly identical for each of the annealing conditions. 相似文献
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A new technique was found which gives high conductivity (~0.1 ohm-1cm-1) p-type material in ZnSe and ZnSxSe1-x. First Ga, In or Tl is diffused into an n-type substrate from a zinc alloyed source at a relatively low temperature. At this
stage, the diffused layer is not yet p-type conductive. A second treatment is needed, heating in zinc vapor at high temperatures.
This treatment converts the Ga, In or Tl containing layer to p-type conductivity and at the same time it drives out some of
the Group IIIA element. It was found that the p-type conductivity depends on the Group IIIA concentration and on the time
and temperature of heating in zinc vapor. The zinc partial pressure controls the zinc vacancy concentration which in turn
appears to control the Group IIIA solubility in the substrate. The p-type conductivity appears to be associated with those
Group IIIA elements which occur both in the monovalent and trivalent form. 相似文献
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