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1.
D. Johnstone T.D. Golding R. Hellmer J.H. Dinan M. Carmody 《Journal of Electronic Materials》2007,36(8):832-836
Reverse current in diodes can be dominated by generation processes, depending exponentially on temperature according to the
rate-limiting step in the generation process. In this report, the current-voltage-temperature (IVT) relationship is analyzed
for several midwave infrared and long-wave infrared (MWIR x = 0.295, LWIR x = 0.233) Hg1−x
Cd
x
Te (MCT) diodes. The energy varied from diode to diode. At high reverse biases, the energy tends toward the band gap energy.
Close to zero bias, the energy ranged from 0.06 to 0.1 eV. Deep level transient spectroscopy (DLTS) showed a broad peak centered
at 55–80 K for the MWIR MCT. Comparison of the DLTS spectrum to a simulation based on the energy and capture cross section
from a rate window analysis shows that the peak is a band of traps. The capacitance transient amplitude increased as the filling
pulse increased from 1 μs to 0.1 s, consistent with capture at a dislocation. A shift to lower temperatures for the peak was
also observed when the diodes are cooled under forward bias. The shift is reversible, indicating that the traps consist at
least partially of a bistable defect. 相似文献
2.
Ashok K. Sood James E. Egerton Yash R. Puri Enrico Bellotti Donald D’Orsogna Latika Becker Raymond Balcerak Ken Freyvogel Robert Richwine 《Journal of Electronic Materials》2005,34(6):909-912
Multicolor infrared (IR) focal planes are required for high-performance sensor applications. These sensors will require multicolor
focal plane arrays (FPAs) that will cover various wavelengths of interest in mid wavelength infrared/long wavelength infrared
(MWIR/LWIR) and long wavelength infrared/very long wavelength infrared (LWIR/VLWIR) bands. There has been significant progress
in HgCdTe detector technology for multicolor MWIR/LWIR and LWIR/VLWIR FPAs.1–3 Two-color IR FPAs eliminate the complexity of multiple single-color IR FPAs and provide a significant reduction of weight
and power in simpler, reliable, and affordable systems. The complexity of a multicolor IR detector MWIR/LWIR makes the device
optimization by trial and error not only impractical but also merely impossible. Too many different geometrical and physical
variables need to be considered at the same time. Additionally, material characteristics are only relatively controllable
and depend on the process repeatability. In this context, the ability of performing “simulation experiments” where only one
or a few parameters are carefully controlled is paramount for a quantum improvement of a new generation of multicolor detectors
for various applications. 相似文献
3.
E. P. G. Smith G. M. Venzor M. D. Newton M. V. Liguori J. K. Gleason R. E. Bornfreund S. M. Johnson J. D. Benson A. J. Stoltz J. B. Varesi J. H. Dinan W. A. Radford 《Journal of Electronic Materials》2005,34(6):746-753
Inductively coupled plasma (ICP) using hydrogen-based gas chemistry has been developed to meet requirements for deep HgCdTe
mesa etching and shallow CdTe passivation etching in large format HgCdTe infrared focal plane array (FPA) fabrication. Large
format 2048×2048, 20-μm unit-cell short wavelength infrared (SWIR) and 2560×512, 25-μm unit-cell midwavelength infrared (MWIR)
double-layer heterojunction (DLHJ) p-on-n HgCdTe FPAs fabricated using ICP processing exhibit >99% pixel operability. The
HgCdTe FPAs are grown by molecular beam epitaxy (MBE) on Si substrates with suitable buffer layers. Midwavelength infrared
detectors fabricated from 4-in. MBE-grown HgCdTe/Si substrates using ICP for mesa delineation and CdTe passivation etching
demonstrate measured spectral characteristics, RoA product, and quantum efficiency comparable to detectors fabricated using
wet chemical processes. Mechanical samples prepared to examine physical characteristics of ICP reveal plasma with high energy
and low ion angle distribution, which is necessary for fine definition, high-aspect ratio mesa etching with accurate replication
of photolithographic mask dimensions. 相似文献
4.
Arsenic-doped mid-wavelength infrared HgCdTe photodiodes 总被引:1,自引:0,他引:1
M. A. Kinch D. Chandra H. F. Schaake H. -D. Shih F. Aqariden 《Journal of Electronic Materials》2004,33(6):590-595
The recently developed Te-rich, liquid-phase-epitaxy growth technology for low arsenic-doped mid-wavelength infrared (MWIR)
HgCdTe with p-type doping concentrations <1015 cm−3 has enabled the fabrication of n+/p photodiodes using the damage associated with a boron ion implantation. The diode properties are presented and compared
to similar diodes fabricated in p-HgCdTe doped with Group IBs. The attraction of the arsenic-doped diode technology is associated
with the fact that the arsenic resides on the Te sublattice and is immune to the Hg interstitial fluxes that are present in
the diode-formation process. This leads to minimal diode spread, limited primarily to the n+ region and, hence, a potential for use in really high-density infrared focal planes. At the same time, the Hg interstitials
generated in the diode-formation process should purge the photodiode volume of fast diffusing species, resulting in a high-quality,
diode-depletion region devoid of many Shockley-Read recombination centers. These aspects of diode formation in this material
are discussed. 相似文献
5.
Majid Zandian D. Scott J. Garnett D. D. Edwall J. Pasko M. Farris M. Daraselia J. M. Arias J. Bajaj D. N. B. Hall S. Jacobson G. Luppino S. Parker 《Journal of Electronic Materials》2005,34(6):891-897
Growth of Hg1−xCdxTe by molecular beam epitaxy (MBE) has been under development since the early 1980s at Rockwell Scientific Company (RSC),
formerly the Rockwell Science Center; and we have shown that high-performance and highly reproducible MBE HgCdTe double heterostructure
planar p-on-n devices can be produced with high throughput for various single- and multiplecolor infrared applications. In
this paper, we present data on Hg1−xCdxTe epitaxial layers grown in a ten-inch production MBE system. For growth of HgCdTe, standard effusion cells containing CdTe
and Te were used, in addition to a Hg source. The system is equipped with reflection high energy electron diffraction (RHEED)
and spectral ellipsometry in addition to other fully automated electrical and optical monitoring systems. The HgCdTe heterostructures
grown in our large ten-inch Riber 49 MBE system have outstanding structural characteristics with etch-pit densities (EPDs)
in the low 104 cm−2 range, Hall carrier concentration in low 1014 cm−3, and void density <1000 cm2. The epilayers were grown on near lattice-matched (211)B Cd0.96Zn0.04Te substrates. High-performance mid wavelength infrared (MWIR) devices were fabricated with R0A values of 7.2×106 Ω-cm2 at 110 K, and the quantum efficiency without an antireflection coating was 71.5% for cutoff wavelength of 5.21 μm at 37 K.
For short wavelength infrared (SWIR) devices, an R0A value of 9.4×105 Ω-cm2 at 200 K was obtained and quantum efficiency without an antireflection coating was 64% for cutoff wavelength of 2.61 μm at
37 K. These R0A values are comparable to our trend line values in this temperature range. 相似文献
6.
针对双色中波红外图像特征空间维数高,不易于对其双波段成像差异进行综合分析的问题,提出了一种基于赋权思想及雷达图的双波段图像差异纹理特征的分析方法。该方法首先构造一个特征选择矩阵,利用其选择出能够满足双波段图像差异分布规律的有效纹理特征;然后利用赋权思想将差异不显著的纹理特征去除;最后采用雷达图对保留下的差异特征进行高维显示,并由雷达图中多边形的形状信息得到维数较少的图形特征。实验数据表明,降维后的特征能够综合反映双波段图像的纹理差异幅度,为后期差异特征驱动的多级融合方法探索奠定了基础。 相似文献
7.
中波红外光学系统无热化设计 总被引:3,自引:1,他引:2
介绍了无热化在红外光学系统中的作用和意义,分析了温度对光学参量的影响,探讨了无热化设计方法及光学被动式无热化基本原理.设计了一种用于320×256制冷型探测器光学被动式无热化中波红外光学系统,镜筒材料采用钛合金,光学材料为硅、锗和硒化锌组合消热差.该系统在-50~70℃温度范围内,最大离焦量小于1倍焦深,空间分辨率17 lp/mm处,光学调制传递函数(MTF)值大于0.7,比较接近衍射极限,探测器单像元内能量集中度大于84%.分析结果表明:该系统具有良好的成像质量和无热效果. 相似文献
8.
A novel simultaneous unipolar multispectral integrated technology approach for HgCdTe IR detectors and focal plane arrays 总被引:4,自引:0,他引:4
W. E. Tennant M. Thomas L. J. Kozlowski W. V. McLevige D. D. Edwall M. Zandian K. Spariosu G. Hildebrand V. Gil P. Ely M. Muzilla A. Stoltz J. H. Dinan 《Journal of Electronic Materials》2001,30(6):590-594
In the last few years Rockwell has developed a novel simultaneous unipolar multispectral integrated HgCdTe detector and focal
plane array technology that is a natural and relatively straightforward derivative of our baseline double layer planar heterostructure
(DLPH) molecular beam epitaxial (MBE) technology. Recently this technology was awarded a U.S. patent. This simultaneous unipolar
multispectral integrated technology (SUMIT) shares the high performance characteristics of its DLPH antecedent. Two color
focal plane arrays with low-1013 cm−2s−1 background limited detectivity performance (BLIP D*) have been obtained for mid-wave infrared (MWIR, 3–5 m) devices at T>130 K and for long-wave infrared (LWIR, 8–10 m) devices
at T∼80 K. 相似文献
9.
Status of the MBE technology at leti LIR for the manufacturing of HgCdTe focal plane arrays 总被引:2,自引:0,他引:2
P. Ferret J. P. Zanatta R. Hamelin S. Cremer A. Million M. Wolny G. Destefanis 《Journal of Electronic Materials》2000,29(6):641-647
This paper presents recent developments that have been made in Leti Infrared Laboratory in the field of molecular beam epitaxy
(MBE) growth and fabrication of medium wavelength and long wavelength infrared (MWIR and LWIR) HgCdTe devices. The techniques
that lead to growth temperature and flux control are presented. Run to run composition reproducibility is investigated on
runs of more than 15 consecutively grown layers. Etch pit density in the low 105 cm−2 and void density lower than 103 cm−2 are obtained routinely on CdZnTe substrates. The samples exhibit low n-type carrier concentration in the 1014 to 1015 cm−3 range and mobility in excess of 105 cm2/Vs at 77 K for epilayers with 9.5 μm cut-off wavelength. LWIR diodes, fabricated with an-on-p homojunction process present
dynamic resistance area products which reach values of 8 103 Ωcm2 for a biased voltage of −50 mV and a cutoff wavelength of 9.5 μm at 77 K. A 320 × 240 plane array with a 30 μm pitch operating
at 77 K in the MWIR range has been developed using HgCdTe and CdTe layers MBE grown on a Germanium substrate. Mean NEDT value
of 8.8 mK together with an operability of 99.94% is obtained. We fabricated MWIR two-color detectors by the superposition
of layers of HgCdTe with different compositions and a mixed MESA and planar technology. These detectors are spatially coherent
and can be independently addressed. Current voltage curves of 60 × 60 μm2 photodiodes have breakdown voltage exceeding 800 mV for each diode. The cutoff wavelength at 77 K is 3.1 μm for the MWIR-1
and 5 μm for the MWIR-2. 相似文献
10.
设计了一款长焦距大变倍比轴向变倍四视场中波红外光学系统.该光学系统由前固定组、变倍调焦组、中间补偿组、后固定组、反射镜一、反射镜二、中继组组成.光学系统采用光学补偿叠加机械补偿方式克服单一光学补偿或机械补偿变焦方式无法同时满足光学系统长焦距、大变倍比、光学系统小型化、光学系统宽温度范围(-40℃~70℃)温度补偿等问题,实现了兼具长焦距和大变倍比的轴向变倍四视场中波红外光学系统.设计结果表明该光学系统像质良好,满足热象仪整机使用要求. 相似文献