InAs/GaSb II类超晶格长波红外焦平面探测器研究

InAs/GaSb II类超晶格材料是第三代红外焦平面探测器的优选材料。报道了一种面阵规模为320×256、像元中心距为30 μm的InAs/GaSb II类超晶格长波红外焦平面器件。在77 K时,该器件的平均峰值探测率为7.6×10¹⁰ cm·Hz^1/2·W^-1,盲元率为1.46%,响应非均匀性为7.55%,噪声等效温差(Noise Equivalent Temperature Difference, NETD)为25.5 mK。经计算可知,这种器件的峰值量子效率为26.2%,50%截止波长为9.1 μm。最后对该器件进行了成像演示。结果表明,该研究为后续的相关器件研制奠定了基础。     

具有低噪声及高线性度的高性能MOCVD-SiNx/AlN/GaN 毫米波MIS-HEMTs

文章在超薄势垒AlN/GaN异质结构上采用金属有机化学气相沉积（MOCVD）原位生长SiN_x栅介质,成功制备了高性能的SiN_x/AlN/GaN金属-绝缘体-半导体高电子迁移率晶体管（MIS-HEMTs）。深能级瞬态谱（DLTS）技术测试SiN_x/AlN的界面信息,显示其缺陷能级深度为0.236 eV,俘获截面为3.06×10^-19 cm^-2,提取的界面态密度为10¹⁰~10¹² cm^-2eV^-1,表明MOCVD原位生长的SiN_x可以有效降低界面态。同时器件表现出优越的直流、小信号和噪声性能。栅长为0.15 μm的器件在2 V的栅极电压（V_gs）下具有2.2 A/mm的最大饱和输出电流,峰值跨导为506 mS/mm,最大电流截止频率（f_T）和最大功率截止频率（f_MAX）分别达到了65 GHz和123 GHz,40 GHz下的最小噪声系数（NF_min）为1.07 dB,增益为 9.93 dB。V_ds = 6 V时对器件进行双音测试,器件的三阶交调输出功率（OIP3）为32.6 dBm,OIP3/P_dc达到11.2 dB。得益于高质量的SiN_x/AlN界面,SiN_x/AlN/GaN MIS-HEMT显示出了卓越的低噪声及高线性度,在毫米波领域具有一定的应用潜力。     

双层异质结碲镉汞甚长波红外焦平面探测器研究进展

报道了甚长波碲镉汞红外焦平面探测器的最新研究进展。采用水平液相外延In掺杂和垂直液相外延As掺杂技术生长p-on-n异质结材料,并基于湿法腐蚀、表侧壁钝化、In柱互连工艺,制备了第一支甚长波碲镉汞台面型焦平面器件。在60 K的工作温度下,该器件的截止波长达到14.28 μm,有效像元率为94.5%,平均峰值探测率达到8.98×10¹⁰ cm·Hz^1/2·W^-1。     

长/长波双色二类超晶格红外探测器研究

报道了长/长波双色二类超晶格红外焦平面探测器组件的研制。通过能带结构设计和分子束外延技术,获得了表面质量良好的长/长波双色超晶格外延材料。突破了长波超晶格低暗电流钝化、低损伤干法刻蚀等关键技术,制备出像元中心距30 μm的320×256长/长波双色InAs/GaSb超晶格焦平面探测器芯片。将芯片与双色读出电路互连,采用杜瓦封装,与制冷机耦合形成探测器组件。组件双波段50%后截止波长分别为7.7 μm（波段1）和10.0 μm（波段2）。波段1平均峰值探测率达到8.21×10¹⁰ cmW^-1Hz^1/2,NETD实现28.8 mK;波段2平均峰值探测率达到6.15×10¹⁰ cmW^-1Hz^1/2,NETD为37.8 mK,获得了清晰的成像效果,实现长/长波双色探测。     

p-on-n长波、甚长波碲镉汞红外焦平面器件技术研究

As注入掺杂的p-on-n结构具有暗电流小、R₀A值高、少子寿命长等优点,是长波、甚长波碲镉汞红外焦平面器件发展的重要趋势。介绍了由昆明物理研究所研究制备的77 K温度下截止波长为9.5 μm、10.1 μm和71 K下14.97 μm 的p-on-n长波、甚长波碲镉汞红外焦平面器件,对器件的响应率、NETD、暗电流及R₀A等性能参数进行测试分析。测试结果表明,器件的有效像元率在99.78%~99.9%之间,器件的NETD均小于21 mK。实现了p-on-n长波、甚长波碲镉汞红外焦平面器件的有效制备。     

512×8像素级数字化长波红外探测器研究

像素级数字化红外探测器具有更高的性能水平和更强的抗干扰能力,是红外探测器技术发展的重要方向之一。通过突破像素级数字化读出电路设计、低峰谷碲镉汞材料外延、器件制备工艺以及倒装互连等关键技术,研制出了一种512×8像素级数字化长波红外探测器组件,并对其性能进行了测试。此探测器的响应波段为7.85～10.17 μm,平均峰值响应率为1.4×10¹¹ LSB/W,响应率非均匀性为9.13%,有效像元率为97.5%,噪声等效温差(Noise Equivalent Temperature Difference, NETD)为4.4 mK,动态范围为90.6 dB。测试结果表明,该探测器能够满足系统要求。     

Ⅱ类超晶格长波红外探测器研究进展

由于具有带隙可调、电子有效质量大、俄歇复合率低等特点,Ⅱ类超晶格在长波红外和甚长波红外探测方面具有独特优势。介绍了长波超晶格探测器制备方面的研究进展,包括能带结构设计、表面缺陷控制、周期结构控制和表面钝化。最后报道了320×256长波超晶格焦平面阵列及其测试性能。结果表明,在77 K工作温度下,该阵列的截止波长为9.6 μm,平均峰值探测率D*为7×10¹⁰ cm·Hz^1/2/W,噪声等效温差 (Noise Equivalent Temperature Difference, NETD)为34 mK,响应非均匀性为7%。     

InyAl1-yAs线性渐变缓冲层对InP基HEMT材料性能的影响

采用气体源分子束外延（GSMBE）技术,研究了InP衬底上In_yAl_1-yAs线性渐变缓冲层对In_0.66Ga_0.34As/In_yAl_1-yAs高迁移率晶体管（HEMT）材料特性影响。研究了不同厚度和不同铟含量的In_yAl_1-yAs线性渐变缓冲层对材料的表面质量、电子迁移率和二维电子气浓度的影响。结果表明,在300 K（77 K）时,电子迁移率和电子浓度分别为8 570 cm²/（Vs）^-1（23 200 cm²/（Vs）-1）3.255E12 cm^-2（2.732E12 cm^-2）。当In_yAl_1-yAs线性渐变缓冲层厚度为50 nm时,材料的表面形貌得到了很好的改善,均方根粗糙度（RMS）为0.154 nm。本研究可以为HEMT器件性能的提高提供强有力的支持。     

10 μm 1 280 × 1 024 HgCdTe中波红外焦平面阵列探测性能提升

对像元尺寸为10 μm的1280×1024碲镉汞（HgCdTe）中波红外焦平面阵列的制备技术和性能进行了研究。通过B⁺注入制备小尺寸n-on-p平面结;采用高平整度HgCdTe外延材料和高精度的倒焊互连技术,实现高的电学连通率;采用多段温度填胶固化和边缘刻蚀工艺减轻HgCdTe器件和读出集成电路（ROICs）之间的热失配,从而降低焦平面器件失效率。在85 K焦平面工作温度下,研制探测器的光谱响应范围为3.67 μm至4.88 μm,有效像元率高达99.95%,并且探测器组件像元的平均噪声等效温差（NETD）和暗电流密度的平均值分别小于16 mK和2.1×10^-8 A/cm²。与像元尺寸为15 μm的探测器相比,10 μm的1280×1024中波红外探测器可获取更加精细的图像,具有更远的识别距离。目前,该技术已成功转移到浙江珏芯微电子有限公司（ZJM）的HgCdTe红外探测器产线。     

12 μm像元间距1280×1024碲镉汞中波红外焦平面探测器的制备及性能研究

武汉高德红外股份有限公司成功研制了像元尺寸为12 μm×12 μm的1280×1024大面阵碲镉汞中波红外焦平面探测器。在优化提升材料性能的基础上,突破了小像元钝化开孔、高密度小尺寸铟柱制备以及高精度大面阵倒焊等关键技术,成功制备出了1280×1024@12 μm碲镉汞中波红外焦平面芯片及组件。其盲元率小于0.5%,响应率非均匀性小于5%。F2探测器的平均噪声等效温差(Noise Equivalent Temperature Difference, NETD)为15 mK,平均峰值探测率为6×10¹¹ cm·Hzsup>1/2·W^-1。F4探测器的平均NETD为18.5 mK,平均峰值探测率为1.2×10¹² cm·Hzsup>1/2·W^-1。另外还提出了一种不稳定像元测试方法,即通过分析两点校正后的成像数据,并利用模块中值和空域噪声的比较,完成对红外图像中不稳定像元的检测和校正。结果表明,校正后的红外成像画质良好,在120 K时器件性能无明显降低。     

On Faster I DDQ Measurements

The purpose of this paper is to introduce a new I _DDQ measurement technique based on active successive approximations, called ASA-I _DDQ. This technique has unique features facilitating a speed-up in I _DDQ measurement. Experimental results suggest that a significant speed-up factor (up to 4) can be obtained over the QuiC-Mon technique. Such a speed-up is a key element in the replacement of single-threshold I _DDQ testing since it amplifies the effectiveness of post-processing techniques.     

Performance analysis of 20 nm gate-length In0.2Al0.8N/GaN HEMT with Cu-gate having a remarkable high ION/IOFF ratio

Abstract： We propose a new structure of InxAll-xN/GaN high electron mobility transistor （HEMT） with gate length of 20 nm. The threshold voltage of this HEMT is achieved as -0.472 V. In this device the InA1N barrier layer is intentionally n-doped to boost the ION/IOFF ratio. The InAlN layer acts as donor barrier layer for this HEMT which exhibits an ION = 10-4.3 A and a very low IOFF = 10-14.4 A resulting in an ION/IoFF ratio of 1010.1. We compared our obtained results with the conventional InAlN/GaN HEMT device having undoped barrier and found that the proposed device has almost l0s times better ION/IOFF ratio. Further, the mobility analysis in GaN channel of this proposed HEMT structure along with DC analysis, C-V and conductance characteristics by using small-signal analysis are also presented in this paper. Moreover, the shifts in threshold voltage by DIBL effect and gate leakage current in the proposed HEMT are also discussed. InAlN was chosen as the most preferred barrier layer as a replacement of AlGaN for its excellent thermal conductivity and very good scalability.     

New op-amp-RC to G m -C transformation method

A new transformation method is proposed and used to transform op-amp-RC circuits to G _m -C ones with only grounded capacitors. The proposed method enables the generation of high-performance G _m -C filters that benefit from the advantages of good and well-known op-amp-RC structures and at the same time feature electronic tunability, high frequency capability and monolithic integration ability. An attractive feature of the proposed method is that it results in G _m -C structures with only grounded capacitors in spite of the presence of floating capacitors in the original op-amp-RC circuits. Ahmed M. Soliman was born in Cairo Egypt, on November 22, 1943. He received the B.Sc. degree with honors from Cairo University, Cairo, Egypt, in 1964, the M.S. and Ph.D. degrees from the University of Pittsburgh, Pittsburgh, PA, U.S.A., in 1967 and 1970, respectively, all in Electrical Engineering. He is currently Professor Electronics and Communications Engineering Department, Cairo University, Egypt. From September 1997–September 2003, Dr. Soliman served as Professor and Chairman Electronics and Communications Engineering Department, Cairo University, Egypt. From 1985–1987, Dr. Soliman served as Professor and Chairman of the Electrical Engineering Department, United Arab Emirates University, and from 1987–1991 he was the Associate Dean of Engineering at the same University. He has held visiting academic appointments at San Francisco State University, Florida Atlantic University and the American University in Cairo. He was a visiting scholar at Bochum University, Germany (Summer 1985) and with the Technical University of Wien, Austria (Summer 1987). In November 2005, Dr. Soliman gave a lecture at Nanyang Technological University, Singapore. Dr. Soliman was also invited to visit Taiwan and gave lectures at Chung Yuan Christian University and at National Central University of Taiwan. In 1977, Dr. Soliman was decorated with the First Class Science Medal, from the President of Egypt, for his services to the field of Engineering and Engineering Education. Dr. Soliman is a Member of the Editorial Board of the IEE Proceedings Circuits, Devices and Systems. Dr. Soliman is a Member of the Editorial Board of Analog Integrated Circuits and Signal Processing. Dr. Soliman served as Associate Editor of the IEEE Transactions on Circuits and Systems I (Analog Circuits and Filters) from December 2001 to December 2003 and is Associate Editor of the Journal of Circuits, Systems and Signal Processing from January 2004–Now.     

Preparation and Thermoelectric Properties of Ag<Subscript>0.5</Subscript>In<Subscript>0.5−<Emphasis Type="Italic">x</Emphasis></Subscript>Pb<Subscript>5</Subscript>Sn<Subscript>4</Subscript>Te<Subscript>10</Subscript>

A series of compounds with composition Ag_0.5In_0.5−x Pb₅Sn₄Te₁₀ (x = 0.05 to 0.20) were prepared by slowly cooling the melts of the corresponding elements, and the effect of In content on the thermoelectric transport properties of these compounds has been investigated. Results indicate that the compounds’ electronic structure is sensitive to In content, and that the carrier concentration of these compounds at room temperature increases from 4.86 × 10¹⁸ cm⁻³ to 3.85 × 10²¹ cm⁻³ as x increases from 0.05 to 0.20. For these compounds, electrical conductivity decreases and Seebeck coefficient increases with increasing In content. Ag_0.05In_0.03Pb_0.5Sn_0.4Te₁₀ shows very low lattice thermal conductivity, and has a maximum dimensionless figure of merit ZT of 1.2 at 800 K.     

CH3NH3PbI3/p-Si异质结的光电特性研究

利用一步溶液法在p型Si衬底上生长有机/无机杂化钙钛矿CH3NH3PbI3薄膜,构成CH3NH3PbI3/p-Si异质结。利用原子力显微镜(AFM)、扫描电子显微镜(SEM)对薄膜形貌和结构进行表征,通过无光照和有光照条件下的电流-电压(I-V)、电容-电压(C-V)测试对异质结的光电特性进行研究。I-V测试结果显示CH3NH3PbI3/p-Si异质结具有整流特性,正反偏压为±5V时,整流比大于70,并在此异质结上观察到了光电转换现象,开路电压为10mV,短路电流为0.16uA。C-V测试结果显示Ag/CH3NH3PbI3/p-Si异质结具有与MIS(金属-绝缘层-半导体)结构相似的C-V特性曲线,与理想MIS的C-V特性曲线相比,异质结的C-V曲线整体沿电压轴向正电压方向平移。C-V特性曲线的这种平移表明Ag/CH3NH3PbI3/p-Si异质结界面存在界面缺陷,CH3NH3PbI3层也可能存在固定电荷。这种界面缺陷是导致CH3NH3PbI3/p-Si异质结开路电压的大幅度降低的重要原因。此外,CH3NH3PbI3薄膜的C-V测试结果显示其具有介电非线性特性,其介电常数约为4.64。     

改进碲镉汞液相外延方法原位生长正组分梯度薄膜材料

研究了液相外延生长条件对碲镉汞薄膜材料组分梯度的影响,建立了指导液相外延生长的理论模型。通过改变水平推舟液相外延工艺的汞损失速率,生长出具有正组分梯度的碲镉汞薄膜材料。针对这种特定条件下生长的碲镉汞外延薄膜,通过腐蚀减薄光谱测试与二次离子质谱测试证实了材料具有正组分梯度结构。与传统方法生长的具有负组分梯度的碲镉汞薄膜相比,这种薄膜材料具有相近的表面形貌与红外透射光谱曲线;且具有较高的晶体质量,其X射线衍射双晶摇摆曲线半峰宽达到28.8 arcsec。     

Performance improvement of c-Si solar cell by a combination of SiNx/SiOx passivation and double P-diffusion gettering treatment

SiN_x/SiO_x passivation and double side P-diffusion gettering treatment have been used for the fabrication of c-Si solar cells. The solar cells fabricated have high open circuit voltage and short circuit current after the double P-diffusion treatment. In addition to better surface passivation effect, SiN_x/SiO_x layer has lower reflectivity in long wavelength range than conventional SiN_x film. As a consequence, such solar cells exhibit higher conversion efficiency and better internal quantum efficiency, compared with conventional c-Si solar cells.     

Partial Fraction Decomposition and Correlation Sequence in 2D Systems

In this paper, results of the one-dimensional (1D) digital filtering are extended to the two-dimensional (2D) case. It introduces a technique and an algorithm for the computation of the product H(z₁,z₂)H(z₁⁻¹,z₂⁻¹). The technique is used to find a minimum phase transfer function of a 2D system such that the previous product matches a given correlation sequence. The algorithm requires less arithmetic operations than the traditional methods. The former is based on a matrix formulation of the product, which is used to investigate the 2D partial fraction decomposition (PFD) and stability.     

微波法制备高活性H1-xSr2Nb3-xMoxO10 (x = 0, 0.05, 0.1, 0.15 and 0.2) 光催化剂

通过微波辅助法制备出高活性H1-xSr2Nb3-xMoxO10光催化材料,制备过程和时间均被大大缩短。采用X射线粉末衍射（XRD）、扫描电镜（SEM）、紫外-可见吸收吸收光谱（UV-Vis DRS）等表征其材料性能。考察了催化材料在40W汞灯辐照下催化降解甲基橙的催化性能。实验结果表明,MoO3的掺入量为15%（摩尔分数）时,材料的光催化性能最优。     

Microstructure of reactively sputtered oxide diffusion barriers

Molybdenum oxide (Mo_1-x O _x ) and ruthenium oxide (RuO₂) films were prepared by rf reactive sputtering of Mo or Ru targets in an O₂/Ar plasma. Both films exhibit metallic conductivities. The influence of the deposition parameters on the phase that forms and on the microstructure of Mo_1-x O _x and RuO₂ films is reported. A phase transformation is observed in Mo_1-x O _x films subjected to heat treatment. The diffusion barrier performance of Mo_1-x O _x and RuO₂ layers interposed between Al and Si is compared.