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采用不同工艺制备了中波碲镉汞(Hg Cd Te)雪崩二极管(APD)器件,利用不同方法对其结特性和增益随偏压变化关系进行了表征,并基于Beck模型和肖克莱解析式进行了拟合分析.结果表明,不同工艺制备的APD器件饱和耗尽区宽度分别为1. 2μm和2. 5μm,较宽的耗尽层有效抑制了高反偏下器件的隧道电流,器件有效增益则从近100提高至1 000以上.用肖克莱解析式拟合Hg Cd Te APD器件增益-偏压曲线,获得了较好的效果.拟合结果与Sofradir公司的J. Rothman的报道相似. 相似文献
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首先简要介绍激光雷达的主要军事应用、激光雷达对接收器的性能需求及激光雷达接收器的现状,综述碲镉汞材料特点、碲镉汞雪崩光电二极管探测器特点,与现有激光雷达接收器相比碲镉汞雪崩光电二极管作为激光雷达接收器的优势及制备技术;综述国外碲镉汞雪崩光电二极管用于激光雷达接收器的发展现状;最后分析我国发展用于激光雷达接收器的碲镉汞雪崩光电二极管可行性。 相似文献
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采用不同工艺制备了中波碲镉汞雪崩二极管(HgCdTe APD)器件,利用不同方法对其结特性和增益随偏压变化关系进行了表征,并基于Beck模型和肖克莱解析式进行了拟合分析。结果表明,不同工艺制备的APD器件饱和耗尽区宽度分别为1.2μm 和2.5μm,较宽的耗尽层有效抑制了高反偏下器件的隧道电流,器件有效增益则从近100提高至1000以上。采用拟合HgCdTe APD器件增益-偏压曲线获得了较好的效果,且拟合得到的参数与Sofradir的Rothman的结果相似。 相似文献
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碲镉汞雪崩光电二极管发展现状 总被引:2,自引:2,他引:0
碲镉汞雪崩光电二极管探测器具有高增益、高带宽和低噪声因数的显著特点,具有下一代焦平面探测器阵列的多功能、主动/被动探测、双波段和高灵敏度等理想特性,在低光通量探测、超光谱、二维/三维成像方面显示出强大的应用潜力。本文简要介绍了碲镉汞雪崩光电二极管主要器件结构、特点及应用现状。 相似文献
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通过对碲镉汞材料进行As^+注入以及退火,成功地制备P-on-N型光伏器件。器件的截止波长为5.5μm,黑体探测率D^*(500K,1K,100)可达2.1×10^10cmHz^1/2W^-1。通过对器件的变温电流-电压关系的测量,利用等效电路进行拟合后,我们发现,限制器件优质因子RoA的主要因素是并联电阻。估计此并联电阻可能由表面漏电和体缺陷引起。 相似文献
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碲镉汞e-APD器件可用于低弱信号检测,碲镉汞材料工艺、器件工艺及器件结构设计对器件性能非常重要。本文采用silvaco软件对平面PIN结构的短波碲镉汞e-APD器件的暗电流、雪崩增益和量子效率进行了仿真分析。结果表明:1)高工作电压下,器件暗电流的主要成分是带间直接隧穿电流;2)工艺因素引入的接近禁带中心的陷阱能级决定器件在中等偏压下的暗电流特性;3)带间直接隧穿和电子碰撞电离主要发生在低掺杂的雪崩放大区;4)在固定偏压下,器件的暗电流和雪崩增益随着雪崩放大区宽度的上升而减少;5)在固定偏压下,器件的雪崩增益随吸收层厚度的增加而轻微增加,同时量子效率逐渐下降。为实现高性能的短波碲镉汞e-APD器件,需要合理设计器件结构和优化材料生长工艺及器件制造工艺。 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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J. Beck C. Wan M. Kinch J. Robinson P. Mitra R. Scritchfield F. Ma J. Campbell 《Journal of Electronic Materials》2006,35(6):1166-1173
Electron injection avalanche photodiodes in short-wave infrared (SWIR) to long-wave infrared (LWIR) HgCdTe show gain and excess
noise properties indicative of a single ionizing carrier gain process. The result is an electron avalanche photodiode (EAPD)
with “ideal” APD characteristics including near noiseless gain. This paper reports results obtained on long-, mid-, and short-wave
cutoff infrared Hg1−xCdxTe EAPDs (10 μm, 5 μm, and 2.2 μm) that use a cylindrical “p-around-n” front side illuminated n+/n-/p geometry that favors
electron injection into the gain region. These devices are characterized by a uniform, exponential, gain voltage characteristic
that is consistent with a hole-to-electron ionization coefficient ratio, k=αh/αe, of zero. Gains of greater than 1,000 have been measured in MWIR EAPDS without any sign of avalanche breakdown. Excess noise
measurements on midwave infrared (MWIR) and SWIR EAPDs show a gain independent excess noise factor at high gains that has
a limiting value less than 2. At 77 K, 4.3-μm cutoff devices show excess noise factors of close to unity out to gains of 1,000.
A noise equivalent input of 7.5 photons at a 10-ns pulsed signal gain of 964 measured on an MWIR APD at 77 K provides an indication
of the capability of this new device. The excess noise factor at room temperature on SWIR EAPDs, while still consistent with
the k=0 operation, approaches a gain independent limiting value of just under 2 because of electron-phonon interactions expected
at room temperature. The k=0 operation is explained by the band structure of the HgCdTe. Monte Carlo modeling based on the
band structure and scattering models for HgCdTe predict the measured gain and excess noise behavior. 相似文献
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采用LPE生长的中波碲镉汞材料,通过B离子注入n-on-p平面结技术制备了规模为256×256,像元中心距为30 μm的碲镉汞APD焦平面探测器芯片。在液氮温度下对其增益、暗电流以及过噪因子等性能参数进行了测试分析,结果表明,所制备的碲镉汞APD焦平面芯片在-8.5 V反偏下平均增益达到166.8,增益非均匀性为3.33%;在0~-8.5 V反向偏置下,APD器件增益归一化暗电流为9.0×10-14~ 1.6×10-13 A,过噪因子F介于1.0~1.5之间。此外,还对碲镉汞APD焦平面进行了成像演示,并获得了较好的成像效果。 相似文献
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J. Rothman N. Baier P. Ballet L. Mollard M. Fournier J. S. Gout J.-P. Chamonal 《Journal of Electronic Materials》2009,38(8):1707-1716
In this communication we report the first results of electro-optical characterization of planar heterostructure HgCdTe avalanche
photodiodes (APDs), which enables the operation of APDs at high gain, at low bias, and with low dark current and/or at high
operating temperature (HOT). The APD is based on a heterostructure in which the photons are detected in a wide-band-gap layer,
and the photoelectrons are amplified in a vertical junction in a confined narrow-gap layer. The dark diffusion current and
thermal background sensitivity of the device are limited by using a thin narrow-band-gap amplification layer. In addition,
the defect-limited dark current is also expected to be reduced due to the reduced volume of the narrow-band-gap depletion
layer. The electro-optical performance was characterized at T = 80 K and T = 200 K for two devices with a nominal thickness of the amplification layer of w = 100 nm and 500 nm, realized in x
Cd = 0.3 Hg-vacancy-doped layers grown by molecular-beam epitaxy (MBE). The measurements show an average gain of 〈M〈 = 10 at a reverse bias of 5 V, which is slightly reduced compared with a conventional APD with x
Cd = 0.3. The thermal diffusion current measured at low reverse bias, V
b = 0.1 V, and at T = 200 K is about 0.1 mA/cm2 to 0.3 mA/cm2, which is a factor of 50 lower than standard x
Cd = 0.3 n-on-p APDs. The quantum efficiency due to absorption in the gain layer is high (QEpeak > 30%), although no antireflecting coating was used, indicating that the device can also be used for high-operating-temperature
thermal detection. 相似文献
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碲镉汞雪崩光电二极管是第三代红外焦平面探测器的主要发展方向之一.提出一种利用离子束刻蚀工艺制备碲镉汞雪崩光电二极管器件的方法,并研究了截止波长、耗尽区厚度与器件增益的关系.利用此方法制备截止波长4. 8μm的中波器件在17 V反向偏置下增益可达1 000.对器件进行了噪声频谱测试,计算了其过剩噪声因子. 相似文献
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Arsenic incorporation during MBE growth of HgCdTe 总被引:2,自引:0,他引:2
We discuss the equilibrium model of the amphoteric behavior of arsenic in HgCdTe and its applicability to material grown by
molecular beam epitaxy. Suggestions are made on how to achieve active incorporation by manipulating the surface orientation,
or by using precursors that provide steric hindrance. 相似文献
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通过2维数值模拟对HgCdTe nBn红外探测器的光电性质进行了研究.理论计算了nBn结构中各层的参数的变化(包含厚度的变化、掺杂浓度的变化以及组分)对器件性能的影响规律.通过优化上述器件结构参数,理论上获得了最优化结构的HgCdTe nBn器件,为获得高性能MBE外延HgCdTe nBn红外探测器提供重要参考. 相似文献
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T. J. De Lyon G. L. Olson J. A. Roth J. E. Jensen A. T. Hunter M. D. Jack S. L. Bailey 《Journal of Electronic Materials》2002,31(7):688-693
The application of spectroscopic ellipsometry (SE) for real-time composition determination during molecular beam epitaxy (MBE)
growth of Hg1−xCdxTe alloys with x>0.5 is reported. Techniques previously developed for SE determination of composition in long-wavelength infrared
(LWIR) HgCdTe have been successfully extended to near-infrared HgCdTe avalanche photodiode (APD) device structures with x
values in the range of 0.6–0.8. Ellipsometric data collected over a spectral range of 1.7–5 eV were used to measure depth
profiles of HgCdTe alloy composition through the use of an optical model of the growth surface. The optical model used a dielectric-function
database collected through the growth of a set of HgCdTe calibration samples with x ranging from 0.6 to 0.8. The sensitivity
of this SE method of composition determination is estimated to be Δx ∼0.0002 at x=0.6, which is sufficiently low to sense
composition changes arising from flux variations of less than 0.1%. Errors in composition determination because of Hg-flux
variations appear to be inconsequential, while substrate-temperature fluctuations have been observed to alter the derived
composition at a rate of −0.0004/°C. By comparing the composition inferred from SE and postgrowth 300 K IR transmission measurements
on a set of APD device structures, the run-to-run precision of the Se-derived composition (at x=0.6) is estimated to be ±0.0012,
which is equivalent to the precision achieved with the same instrumentation during the growth of mid-wavelength infrared (MWIR)
HgCdTe alloys in the same MBE system. 相似文献