9μm Cutoff 128×128 AlGaAs/GaAs Quantum Well Infrared Photodetector Focal Plane Arrays

报道了128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列的设计和制作. 采用金属有机化学气相淀积外延技术生长外延材料，并在GaAs集成电路工艺线上完成工艺制作. 为得到器件参数，设计制作了台面尺寸为300μm×300μm的大面积测试器件；77K下2V偏压时暗电流密度为1.5E-3A/cm2; 80K工作温度下，器件峰值响应波长为8.4μm，截止波长为9μm，黑体探测率DB为3.95E8 (cm·Hz1/2) /W. 将128×128元 AlGaAs/GaAs量子阱红外焦平面探测器阵列芯片与相关CMOS读出电路芯片倒装焊互连，在80K工作温度下实现了室温环境目标的红外热成像，盲元率小于1%.     

256×1甚长波量子阱红外焦平面研究

GaAs/AlGaAs量子阱红外探测器由于其所依据的GaAs基材料较为成熟的材料生长和器件制备工艺,使其特别适合于高均匀性、大面积红外焦平面的应用。报道了甚长波256×1元GaAs/AlGaAs多量子阱红外焦平面器件的研制成果, 探测器的峰值波长为15 μm,响应带宽大于1.5 μm。在40 K工作温度下,器件的平均黑体响应率Rp=3.96×106 V/W, 平均黑体探测率为D*=1.37×109 cm·Hz1/2/W, 不均匀性为11.3%, 并应用研制的器件获得了物体的热像图。     

160×128元多量子阱长波红外焦平面探测器件研制

报道了新研制出的160×128元GaAs/AlGaAs多量子阱长波红外焦平面器件。使用MBE的方法在半绝缘的GaAs衬底上生长器件结构；开发了用普通光刻技术和离子束刻蚀法制备2D光栅技术，以及探测器芯片与读出电路互联技术。在77 K时测试，器件的平均峰值探测率Dλ*=1.28×1010 cmW-1Hz1/2，峰值波长为λp=8.1 μm，截止波长为λc=8.47 μm。器件的非盲元率≥98.8％，不均匀性10％。     

128×128三电极中/长波双色量子阱红外探测器

量子阱红外探测器(QWIP)阵列具有重要的实用意义。国外的研究已经相当成熟,但是在国内,量子阱红外探测器阵列的研究水平还较低,尤其是对于双色量子阱红外探测器阵列的研究更是刚刚起步。文中使用GaAs/AlGaAs、InGaAs/AlGaAs应变量子阱和三端电极引出的器件结构研制出128×128中/长波双色量子阱红外探测器阵列。该结构实现了同像元同时引出双色信号。器件像元中心距为40μm,像元有效面积为36μm×36μm。探测器芯片与读出电路互连并完成微杜瓦封装。在65 K条件下测试,峰值波长为:中波5.37μm,长波8.63μm,器件的平均峰值探测率为:中波4.75×109cmHz1/2W-1,长波3.27×109cmHz1/2W-1。并进行了双波段的红外演示成像。     

9μm截止波长128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列

报道了128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列的设计和制作.采用金属有机化学气相淀积外延技术生长外延材料,并在GaAs集成电路工艺线上完成工艺制作.为得到器件参数,设计制作了台面尺寸为300μm×300μm的大面积测试器件;77K下2V偏压时暗电流密度为1.5×10-3A/cm2;80K工作温度下,器件峰值响应波长为8.4μm,截止波长为9μm,黑体探测率DB 为3.95×108(cm·Hz1/2)/W.将128×128元 AlGaAs/GaAs量子阱红外焦平面探测器阵列芯片与相关CMOS读出电路芯片倒装焊互连,在80K工作温度下实现了室温环境目标的红外热成像,盲元率小于1%.     

中波-长波双色量子阱红外探测器

采用n型掺杂的AlGaAs/GaAs和AlGaAs/InGaA多量子阱材料,基于MOCVD外延生长技术,利用成熟的GaAs集成电路加工工艺,设计并制作了不同结构的中波-长波双色量子阱红外探测器(QWIP)器件,器件采用正面入射二维光栅耦合,光栅周期设计为4μm,宽度2μm;对制作的500μm×500μm大面积双色QWIP单元器件暗电流、响应光谱、探测率进行了测试和分析。在-3V偏压、77K温度和300K背景温度下长波(LWIR)和中波(MWIR)QWIP的暗电流密度分别为0.6、0.02mA/cm2;-3V偏压、80K温度下MWIR和LWIR QWIP的响应光谱峰值波长分别为5.2、7.8μm;在2V偏压、65K温度下,LWIR和MWIR QWIP的峰值探测率分别为1.4×1011、6×1010cm.Hz1/2/W。     

9μm截止波长128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列

报道了128×128 AlGaAs/GaAs量子阱红外焦平面探测器阵列的设计和制作.采用金属有机化学气相淀积外延技术生长外延材料,并在GaAs集成电路工艺线上完成工艺制作.为得到器件参数,设计制作了台面尺寸为300μm×300μm的大面积测试器件;77K下2V偏压时暗电流密度为1.5×10-3A/cm2;80K工作温度下,器件峰值响应波长为8.4μm,截止波长为9μm,黑体探测率DB 为3.95×108(cm·Hz1/2)/W.将128×128元 AlGaAs/GaAs量子阱红外焦平面探测器阵列芯片与相关CMOS读出电路芯片倒装焊互连,在80K工作温度下实现了室温环境目标的红外热成像,盲元率小于1%.     

双色量子阱红外探测器大面阵芯片的研制

采用GaAs/AlGaAs和InGaAs/AlGaAs多量子阱,研制出了双色同像素读取结构的中波/长波量子阱红外探测器及160×128元中波/长波双色多量子阱红外探测器芯片。器件的材料结构生长是采用分子束外延技术,在5.08 cm半绝缘GaAs衬底上完成的。发展了双色大面阵制备工艺,二维光栅的制备使用标准光刻和离子束刻蚀技术。在77 K时,对量子阱红外探测器测试,得到中、长波段峰值探测率分别为Dλ*=（1.61～1.90）×1010 cmHz1/2W-1和（1.54～2.67）×1010 cmHz1/2W-1。中、长波段峰值波长分别为(2.7~3.8) μm和8.3 μm。     

128×160元GaAs/AlGaAs多量子阱长波红外焦平面阵列

研制了128×160元GaAs/AlGaAs多量子阱红外焦平面阵列，它是目前国内报道的最大像元数的量子阱红外焦平面阵列. 77K时，器件的平均黑体响应率Rv＝2.81e7V/W,平均峰值探测率Dλ=1.28e10cm·W-1·Hz1/2，峰值波长λp=8.1μm，器件的盲元率为1.22%.     

As元素分子态对InGaAs/AlGaAs量子阱红外探测器性能的影响

对As2和As4两种不同分子态下利用分子束外延技术(MBE)生长的单层AlGaAs薄膜和GaAs基InGaAs/AlGaAs量子阱红外探测器(QWIP)的性能进行了研究,发现As2条件下生长的单层AlGaAs材料荧光强度更大、深能级缺陷密度更低;相对于As4较为复杂的吸附、生长机制引入的缺陷,在As2条件下生长的InGaAs/AlGaAs QWIP具有更低的暗电流密度、更好的黑体响应、更高的比探测率和更优异的器件均匀性。生长制备的InGaAs/AlGaAs QWIP在60K的工作温度、-2V偏压下,暗电流密度低至7.8nA/cm2,光谱响应峰值波长为3.59μm,4V偏压下峰值探测率达到1.7×1011 cm·Hz1/2·W-1。另外,通过As元素的不同分子态下InGaAs/AlGaAs QWIP光响应谱峰位的移动可以推断出As元素的不同分子态也会影响In的并入速率。     

AlGaAs/GaAs quantum well infrared photodetector focal plane array based on MOCVD technology

128 × 128, 128 × 160 and 256 × 256 AlGaAs/ GaAs quantum well infrared photodetector (QWIP) focal plane arrays (FPA) as well as a large area test device are designed and fabricated. The device with n-doped back-illuminated AIGaAs/GaAs quantum structure is achieved by metal organic chemical vapor deposition (MOCVD) epitaxial growth and GaAs integrated circuit processing technology. The test device is valued by its dark current performance and Fourier transform infrared spectroscopy (FTIR) spectra at 77 K. Cut off wavelengths of 9 and 10.9 μm are realized by using different epitaxial structures. The blackbody detectivity DB* is as high as 2.6 × 109 cm· Hz1/2·W-1. The 128 × 128 FPA is flip-chip bonded on a CMOS readout integrated circuit with indium (In) bumps. The infrared thermal images of some targets under room temperature background have been successfully demonstrated at 80 K operating temperature. In addition, the methods to further improve the image quality are discussed.     

GaAs/AlGaAs量子阱长波10.55 μm红外焦平面探测器

利用GaAs/AlGaAs量子阱结构,研制了像元规模为640×512、中心响应波长在10.55 μm附近的红外焦平面阵列器件,与50 K集成式制冷机耦合后,测试了相关性能,其等效噪声温差达到22.5 mK。焦平面组件通过了初步的开关机试验以及热真空试验后,表现良好。考虑封装冷屏导致在面源黑体测试时产生的焦面照度不均匀问题进行了数值计算,并分析了与近似解析计算的误差,表明当F数变小时应当采用数值计算,并认为探测器测试的非均匀性主要由照度不均匀贡献。针对10.55 μm量子阱探测器,利用开源的MEEP FDTD软件,进行了近场耦合的光场分布计算,计算结果表明目前的结构参数在光衍射方面是比较接近优化的。     

640×486 long-wavelength two-color GaAs/AlGaAs quantum wellinfrared photodetector (QWIP) focal plane array camera

We have designed and fabricated an optimized long-wavelength/very-long wavelength two-color quantum well infrared photodetector (QWIP) device structure. The device structure was grown on a 3-in semi-insulating GaAs substrate by molecular beam epitaxy (MBE). The wafer was processed into several 640×486 format monolithically integrated 8-9 and 14-15 μm two-color (or dual wavelength) QWIP focal plane arrays (FPAs). These FPAs were then hybridized to 640×486 silicon CMOS readout multiplexers. A thinned (i.e., substrate removed) FPA hybrid was integrated into a liquid helium cooled dewar for electrical and optical characterization and to demonstrate simultaneous two-color imagery. The 8-9 μm detectors in the FPA have shown background limited performance (BLIP) at 70 K operating temperature for 300 K background with f/2 cold stop. The 14-15 μm detectors of the FPA reaches BLIP at 40 K operating temperature under the same background conditions. In this paper we discuss the performance of this long-wavelength dualband QWIP FPA in terms of quantum efficiency, detectivity, noise equivalent temperature difference (NEΔT), uniformity, and operability     

LWIR HgCdTe on Si detector performance and analysis

We have fabricated a series of 256 pixel×256 pixel, 40 μm pitch LWIR focal plane arrays (FPAs) with HgCdTe grown on (211) silicon substrates using MBE grown CdTe and CdSeTe buffer layers. The detector arrays were fabricated using Rockwell Scientific’s double layer planar heterostructure (DLPH) diode architecture. The 78 K detector and focal plane array (FPA) performance are discussed in terms of quantum efficiency (QE), diode dark current and dark current operability. The FPA dark current and the tail in the FPA dark current operability histograms are discussed in terms of the HgCdTe epitaxial layer defect density and the dislocation density of the individual diode junctions. Individual diode zero bias impedance and reverse bias current-voltage (I-V) characteristics vs. temperature are discussed in terms of the dislocation density of the epitaxial layer, and the misfit stress in the epitaxial multilayer structure, and the thermal expansion mismatch in the composite substrate. The fundamental FPA performance limitations and possible FPA performance improvements are discussed in terms of basic device physics and material properties.     

Arrays of 128×128 photodetectors based on HgCdTe layers and multilayer heterostructures with GaAs/AlGaAs quantum wells

A technology has been elaborated and photodetector modules based on Hg_1−x Cd_xTe/GaAs heterostructures and GaAs/AlGaAs multiquantum-well structures grown by molecular-beam epitaxy were fabricated for the 3–5 and 8–12 μm spectral ranges. The photosensitive HgCdTe layers were grown on the GaAs substrates with the intermediate buffer layer of CdZnTe. To decrease the surface effect on the recombination processes, the graded-gap Hg_1−x Cd_xTe layers with x increasing towards the surface were grown. A silicon multiplexer was designed and fabricated by CMOS/CCD technology with a frame rate of 50 Hz. The hybrid microassembly of the photodetector array and the multiplexer was produced by group cold welding on indium columns while monitoring the connection process. The fabricated 128×128 modules based on HgCdTe layers with the cutoff wavelengths 6 and 8.7 μm had a temperature resolution of 0.02 K and 0.032 K, respectively, at a temperature of 78 K and a frame rate of 50 Hz. The photosensitive GaAs/AlGaAs multilayer quantum well structures were fabricated by MBE. It is shown that the technology developed allows 128×128 multielement photodetector arrays (λ_peak=8 μm) to be produced with a temperature resolution of 0.021 K and 0.06 K at operating temperatures of 54 K and 65 K, respectively. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 35, No. 9, 2001, pp. 1159–1166. Original Russian Text Copyright ? 2001 by Ovsyuk, Sidorov, Vasil’ev, Shashkin.