高探测率的GaAs/AlGaAs多量子阱长波长红外探测器

探测器采用50周期GaAs/Al_(0.3)Ga_(0.7)As多量子阱结构的分子束外延材料,并制成直径为320μm的台面型式单管.其器件主要性能和指标如下:探测峰值波长为 9.2 μm,工作温度为77 K,峰值电压响应率 R_v= 9.7× 10~5V/W,峰值探测率 D~*= 6.2 × 10~(10)cmHz~(1/2)/W.     

光学浸没型双色HgCdTe光导探测器

本文利用光学浸没原理以及叠层双色探测器工作原理,研制出浸没型3μm～5μm,8μm～12μm双色HgCdTe光导探测器.3μm～5μm探测器峰值探测率可达10~(11)cmHz~(1/2)/W;8μm～14μm探测器峰值探测率达7.0×10~(10)cmHz~(1/2)W.峰值响应率可达10~3V/W.     

"风云二号"卫星用水汽/热红外双波段探测器

报导了我国第一颗静止气象卫星"风云二号"卫星多通道扫描辐射计中使用的水汽/热红外双波段6.3～7.6μm、10.5～12.5μm四元碲镉汞红外探测器性能.探测器工作温度T=100K时,热红外波段探测率D*(10.5～12.5)为3.4×1010cmHz1/2/W,波段响应率R(10.5～12.5)为3.0×104(V/W);水汽波段探测率D*(6.3～7.6)为1.1×1011cmHz1/2/W,波段响应率R(6.3～7.6)为6.1×104(V/W).探测器经过环境应力筛选,密封筛选,电应力筛选,抗太阳辐照试验,电子、质子辐照试验以及高真空、低温工作寿命试验,获得了探测器可靠性寿命数据,器件失效率小于7.5×10-6/h.     

长波大面积HgCdTe光导红外探测器的研究

研制的长波大面积HgCdTe光导红外探测器的面积为2.1×2.1mm~2,在80K时探测率D_p~*=1.86×10~(10)cmHz~(1/2)W~(-1),响应率R_p=386VW~(-1),长波限λ_(co)(50%)>18μm.还研制了带有低温聚光器组合件结构的新型探测器,D_p~*=7.3×10~(10)cmHz~(1/2)W~(-1),λ_(co)(50%)>16μm.     

双色红外探测器研究

为适应遥感、遥测及精确制导技术的发展,我们已研制出一定性能的CdS/HgCdTe(0.3～0.5μm/3～5μm)、Si/InSb(0.3～1.05μm/3～5μm)、Si/HgCdTe(0.3～1.05μm/3～5μm)、HgCdTe/LiTaO_3(3～5μm/8～14μm)、HgCdTe/HgCdTe(3～5μm/8～14μm)等多种双色红外探测器。其中HgCdTe/HgCdTe(3～5μm/8～14μm)光导双色探测器的峰值探测率D~*(5.1,980,1)=2.1×10~(10)cmHz~(1/2)/W,D~*(9.8,980,1)=8.1×10~9cmHz~(1/2)/W, 峰值响应率R(5.1,980,1)=1.3×10~4V/W,R(9.8,980,1)=373V/W。文中介绍了双色探测器的设计、结构、制备及器件的性能水平。     

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%.     

新型Ge_xSi_(1-x)/Si异质结远红外探测器

用分子束外延技术结合硅平面工艺研制成了Ge_xSi_(1-x)/Si异质结远红外探测器。测试结果表明,界面势垒高度低于0.09eV,预计对应的工作波长可从2μm到12μm以上。50K时的探测率(黑体_(873k)~*)优于2×10~8cm·Hz~(1/2)/W,30K为6×10~8cmHz~(1/2)/W,对500K黑体,30K工作温度下D_(500k)~*为1.6×10~8cm·Hz~(1/2)/W。由于探测器为宽带型,虽然峰值D~*并不很高,但在30℃的环境辐射背景下,对人体温度的辐射也有较强烈的响应。     

两种新型红外探测器

华北光电技术研究所近期研制成下述两种红外探测器: 1.碲锡铅异质结红外探测器 这是以碲锡铅晶体作衬底、用液相“异质结”外延技术制成的红外探测器。响应波长为8～12μm,适于室温目标的探测、成象。可应用于红外前视、医用热成象、遥感、跟踪、污染监控等方面。该器件的探测率D一般大于1×10~(10)cm·Hz 1/2/W,最高的D≥4～5×10~(10)cm·Hz 1/2/W;峰值波长λ_p≥10μm。经     

用CMOS工艺方法制作的低成本非致冷红外探测器（上）

本文介绍用标准的 n 阱 CMOS 工艺方法实现的两种低成本非致冷红外微测辐射热计探测器，并对它们的性能进行了比较，其中一种探测器基于悬置式 n 阱电阻器，它是用0.8μm 的 CMOS 工艺方法制作的，其像元尺寸为80μm×80μm,占空因数为13%；另一种探测器基于悬置的p~+激活/n 阱二极管，这是用0.35μm 的 CMOS 工艺方法制作的，其像元尺寸为 40μm×40μm，占空因数为44%,在 CMOS 制作之后，这些探测器用简单的整体微机械加工方法即可获得，无需任何复杂的平版印刷或者淀积工序，在20μA 的偏置电流和'80毫乇的真空条件下，测得的二极管型探测器的响应率(π)为4970V/W，热时间常数为35.8ms，在带宽为4kHz 时，测得的均方根噪声为0.52μV，结果其探测率(D~#)为9.7×10~8cmHz~1/2/W.与二极管型探测器相比，电阻器型 n 阱探测器在1.68V 的偏压下能达到同样的直流响应率，但其自热却10倍于二极管型探测器，在带宽为4kHz 时，这种探测器的均方根噪声为0.81μV，由此得出的探测率(D~*)为8.9×10~8cmHz~1/2/W。如果给电阻器型 n 阱探测器施加更高的偏压，其探测率还可提高，但其自热会更高，由于二极管型探测器在像元尺寸较小和所加偏压更低的情况下仍具有比较高的响应率，因此更适用于低成本大规格红外探测器列     

带耦合光栅的量子阱红外探测器研制

报导了带二维衍射光栅的 12 8元线列GaAs/AlGaAs多量子阱长波红外焦平面探测器的研究成果。探测器光吸收峰值波长λP=8.9μm ,采用垂直入射光耦合的工作模式 ,在 80K工作温度下其平均黑体电压响应率为 2 .75× 10 4 V/W ,平均黑体探测率为 2 .5 2× 10 9cmHz1/ 2 /W ;电压响应率和探测率的非均匀性分别 5 .2 %和 8.3%。 12 8元线列探测器与 6 4元CMOS读出电路对接后与光学系统、扫描系统、数据采集系统和图像显示系统等组成红外成像演示系统 ,实验室获得了清晰的人体手部热像和余热图像     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Study of waveguide coupling efficiency in hybrid silicon lasers

This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel＇s.     

Curved crystal spectrometer for the measurement of X-ray lines from laser-produced plasmas

In order to diagnose the laser-produced plasmas, a focusing curved crystal spectrometer has been developed for measuring the X-ray lines radiated from a laser-produced plasmas. The design is based on the fact that the ray emitted from a source located at one focus of an ellipse will converge on the other focus by the reflection of the elliptical surface. The focal length and the eccentricity of the ellipse are 1350 mm and 0.9586, respectively. The spectrometer can be used to measure the X- ray lines in the wavelength range of 0.2-0.37 nm, and a LiF crystal （200） （2d = 0.4027 nm） is used as dispersive element covering Bragg angle from 30° to 67.5°. The spectrometer was tested on Shengnang- Ⅱ which can deliver laser energy of 60-80 J/pulse and the laser wavelength is 0.35 μm. Photographs of spectra including the 1 s2p ^1P1-1s^2 ^1S0 resonance line（w）, the 1s2p ^3P2-1s^2 1S0 magnetic quadrupole line（x）, the 1s2p ^3P1-1 s^2 ^1S0 intercombination lines（y）, the 1 s2p ^3S~1-1 s^2 ^1S0 forbidden line（z） in helium-like Ti Ⅹ Ⅺ and the 1 s2s2p ^2P3/2-1 s622s ^2S1/2 line（q） in lithium-like Ti Ⅹ Ⅹhave been recorded with a X-ray CCD camera. The experimental result shows that the wavelength resolution（λ/△ 2） is above 1000 and the elliptical crystal spectrometer is suitable for X-ray spectroscopy.     

Preparation and Characterization of TaN ALD Precursors

High purity organic-tantalum precursors for thin film ALD TaN were synthesized and characterized.Vapor pressure and thermal stability of these precursors were studied.From the vapor pressure analysis,it was found that TBTEMT has a higher vapor pressure than any other published liquid TaN precursor,including TBTDET,TAITMATA,and IPTDET.Thermal stability of the alkyl groups on the precursors was investigated using a 1H NMR technique.The results indicated that the tertbutylimino group is the most stable group on TBTDET and TBTEMT as compared to the dialkylamido groups.Thermal stability of TaN precursors decreased in the following order:TBTDET ＞ PDMAT ＞ TBTEMT.In conclusion,precursor vapor pressure and thermal stability were tuned by making slight variations in the ligand sphere around the metal center.     

Electronic Structure of Semiconductor Nanocrystals

This paper reviews our recent development of the use of the large-scale pseudopotential method to calculate the electronic structure of semiconductor nanocrystals, such as quantum dots and wires, which often contain tens of thousands of atoms. The calculated size-dependent exciton energies and absorption spectra of quantum dots and wires are in good agreement with experiments. We show that the electronic structure of a nanocrystal can be tuned not only by its size,but also by its shape. Finally,we show that defect properties in quantum dots can be significantly different from those in bulk semiconductors.     

A rigorous proof of MIMO channel capacity’s increase with antenna number

It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output（MIMO） communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.