大功率半导体激光器脉冲驱动电源研制

研制了一种大电流、窄脉宽的半导体激光器驱动电源,该驱动电源激励半导体激光器用于驱动砷化镓光导开关。驱动电路采用高速金属氧化物半导体场效应晶体管(MOSFET)作为开关,为半导体激光器提供一个前沿快(1.2 ns)、脉宽窄(15 ns)、峰值电流大(72 A)的脉冲驱动电流,并可根据需要调节电路中的参数,获得不同前沿、不同脉宽、不同峰值的电流脉冲。半导体激光器输出的激光脉冲功率可达75 W,上升前沿约3 ns,抖动均方根小于200 ps,可稳定触发工作在非线性模式下的砷化镓光导开关。     

高重频可调小型高功率半导体激光电源研究

为了获得高功率、高重频半导体激光脉冲,设计了一种体积小、重量轻、造价低的纳米级大功率半导体激光器驱动电源。采用改进的单稳态触发器产生窄脉冲,经放大后驱动快速开关MOSFET获得大电流窄脉冲;电源脉冲电流驱动能力0A～80A,脉冲上升时间2.8ns,下降时间3.8ns,脉冲宽度5ns～500ns范围内可调,最小5.2ns,重复频率可达200kHz。用该电源实验测试了激光波长为905nm的半导体激光器,在重复频率为10kHz时,激光脉冲峰值功率达到70W以上。结果表明,采用窄脉冲驱动MOSFET可以得到高重复频率10ns以内的大电流窄脉冲,可以驱动大功率半导体激光器,若驱动100A以上的激光器需进一步研究。     

一种脉宽可调的窄脉冲激光器驱动电路设计

针对半导体激光器中纳秒级脉宽的驱动电路脉冲宽度范围小、无法调节的问题,提出一种脉宽可调的窄脉冲激光器驱动电路设计方案.根据现场可编程逻辑门阵列(FPGA)技术和半导体激光的工作原理,搭建了半导体激光驱动电路的一般模型,并进行了仿真与实验分析.以FPGA开发板为控制核心,使用高速金属氧化物半导体场效应晶体管(MOSFET)驱动芯片DE375作为开关,实现驱动电源及半导体激光器的精密控制.该电路输出的脉冲电流幅值可达40A,脉冲宽度为5～200 ns,重复频率为0～50 kHz,上升沿宽度小于5 ns,有效增强了半导体激光器驱动电路的功能.     

基于LDMOS的可调窄脉冲半导体激光器驱动源研究

介绍了一种利用横向双扩散金属氧化物半导体(LDMOS)作为开关器件驱动激光半导体的设计方法。通过对半导体激光器驱动电路原理的分析,并结合PSPICE建立射频功率晶体管的电路模型,经过理论分析和计算从而获得更优化的驱动电路;采用高速电流反馈型运算放大器构成电流串联负反馈电路从而得到稳定的输出电流,有效地提高了窄脉冲信号的转换速率和频响特性。实验结果表明,半导体激光器输出电流脉宽20 ns-CW可调,上升和下降时间小于10 ns,幅度最高可达2 A,重复频率为0~10 MHz。实验结果验证了设计思路的可行性,进一步提高了半导体激光器的输出指标。     

基于FPGA脉宽可调的窄脉冲激光器驱动电路设计

针对激光驱动电路纳秒脉冲宽度无法调节的问题,设计了一种新型的脉宽可调的窄脉冲激光驱动电路。利用FPGA和激光二极管的工作原理,设计并搭建半导体激光器驱动电路。电路采用高速MOSFET作为开关器件驱动激光二极管SPLPL90-3,并利用LTspice仿真软件分析激光驱动电路中电源电压、储能电容和阻尼电阻对驱动脉冲的影响,最终选择最佳的电路参数。当电源电压为150 V,储能电容为1 nF,阻尼电阻为2Ω时,最终输出激光二极管的电流为39.7 A,脉冲宽度6 ns,上升沿3 ns,满足了大电流纳秒脉冲半导体激光器驱动电路的设计要求。     

基于雪崩晶体管的脉冲半导体激光电源的设计

介绍了一种基于时间延迟和雪崩晶体管的纳秒级窄脉冲半导体激光器电源,该电源主要由脉冲发生电路、雪崩电路组成。实践证明,该电源可以作为一种简单的纳秒脉冲产生装置,产生脉宽〈30ns、峰值为1A的电流脉冲,用于驱动普通半导体激光器。     

基于DE150的高速大电流窄脉宽半导体激光电源

总结了一种基于射频MOSFET管的高速大电流窄脉宽半导体激光驱动源设计方法,运用PSpice对整个驱动电路进行了仿真,最后利用DE150-201N09A MOSFET管制作了面积为12cm2的电路板,测试结果表明半导体激光器输出电流脉宽10ns左右、上升时间4ns,最大脉冲电流27A,最高重复频率可达50 kHz。     

基于频率补偿的窄脉冲量子级联激光器快速驱动技术

脉冲量子级联激光器(QCL)因自热效应会导致谱线展宽,故需极短的电流脉冲驱动。理论极限线宽所需的脉宽为5~15 ns,但由于环路寄生参数的影响,窄脉冲会引起信号过冲或振荡,因此目前商用的QCL驱动器无法满足这个要求。为获得更理想的激光器线宽,在常规脉冲恒流电路的基础上,采用频率补偿的方法来消除过冲和振荡,并设计了一款稳定的纳秒级激光器驱动电路。实验结果显示该驱动装置实现了峰值电流0~2 A、脉宽8.4~200 ns、上升时间4 ns、过冲1%的脉冲电流输出。使用中国科学院半导体研究所研制的波长4.6m激光器和傅里叶变换光谱仪进行测试,当驱动脉宽由100 ns减小到10 ns时,激光器线宽由0.35 cm-1线性递减到0.12 cm-1。综合验证表明,所设计的驱动装置实现了稳定的窄脉冲电流输出,尤其适用于量子级联激光器的窄线宽驱动及应用。     

纳秒脉冲半导体激光驱动器的研究

为了获得高功率、高重复频率的纳秒级光脉冲,介绍了一种基于Marx bank脉冲发生原理的纳秒脉冲激光驱动器的设计,以及设计过程中雪崩晶体管的选取.该驱动器采用一级小雪崩管对触发脉冲进行陡化,由小雪崩管产生的脉冲对Marx bank电路进行触发,以获得大电流窄脉冲,用于驱动半导体激光器.设计所得驱动器的峰值电流为12.5A、半峰全宽为1.51ns、重复频率为100kHz,实现了大幅度纳秒脉冲半导体激光驱动器的设计要求.结果表明,对触发脉冲的陡化,可以降低后一级Marx bank电路的雪崩电压,同时使得脉宽更窄,这将更加有利于驱动半导体激光器.     

窄脉冲大电流半导体激光器驱动电路设计与仿真

设计出了一种窄脉冲大电流的半导体脉冲激光器驱动电路,并对电路进行理论分析以及Multisim仿真研究。相比以往研究,本仿真研究中考虑了电路和LD本身的寄生参数,使得仿真与实际电路更加吻合。该电路结构简单,采用了专用的MOSFET硬件关断加速电路和电容充放电方式向负载提供瞬时窄脉冲大电流的脉冲输出,脉冲宽度低于2.5ns,上升时间低于3.5ns,峰值电流超过20A。     

Technology innovation and process integrations for sub-100nm gate patterning

This paper presents a brief overview of the Applied Centura(R)DPS(R)system,configured with silicon etch DPS Ⅱ chamber, with emphasis on discussing tuning capability for CD uniformity control. It also presents the studies of etch process chemistry and film integration impact for an overall successful gate patterning development. Discussions will focus on resolutions to key issues, such as CD uniformity, line-edge roughness, and multilayer film etching integration.     

White organic light-emitting devices based on fac tris（2- phenylpyridine） iridium sensitized 5,6,11,12-tetraphenylnap -hthacene

We have fabricated the white organic light-emitting devices （WOLEDs） based on 4,4＇ -bis（2,2 -diphenyl vinyl）-1,1＇ - biphenyl （DPVBi） and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene （rubrene）. The device structure is ITO/2T-NATA （20 nm）/NPBX （20 nm）/CBP： x%Ir（ppy）3：0.5% rubrene （8 nm）/NPBX （5 nm）/DPVBi （30 nm）/Alq（30 nm）/LiF（0.5 nm）/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris （2-phenylpyridine） iridium [Ir（ppy）3], acts as a yellow light-emitting layer, and N,N＇ -bis- （1-naphthyl）- N,N＇ -diphenyl -1, 1＇ -biphenyl-4,4＇ -diamine （NPBX） acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir （PPY）3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.     

Complete approach to automatic identification and subpixel center location for ellipse feature

To meet the need of automatic image features extraction with high precision in visual inspection, a complete approach to automatic identification and sub-pixel center location for similar-ellipse feature is proposed. In the method, the feature area is identified automatically based on the edge attribute, and the sub-pixel center location is accomplished with the leastsquare algorithm. It shows that the method is valid, practical, and has high precision by experiment. Meanwhile this method can meet the need of instrumentation of visual inspection because of easy realization and without man-machine interaction.     

小角度扩展相关性近似算法分析

本论文提出一种在多天线MIMO信道相关性建模中小角度扩展近似理论算法,并应用于分析MIMO系统性能。分析中分别对三种不同角能量分布情况下的空间相关性研发快速近似计算法,并同时提出双模(Bi-Modal)角能量分布情况下的近似运算。通过分析这些新方法的近似效率,可以得到计算简单、复杂度低、而且符合实际的MIMO相关信道矩阵,对系统级的快速高效计算法的研究和系统级的评估以及误差分析具有重要的意义。     

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.     

A Versatile Mixed-Signal Pin Approach for Cost-Effective Test of Automotive ICs

Integrated circuits (ICs) intended for increasingly sophisticated automotive applications bring unique test demands. Advanced ICs for applications such as highly integrated automatic braking system (ABS) and airbag controllers combine high voltage digital channels, significant VI demands and precise timing capability. Along with continued missioncritical reliability concerns, the trend toward higher voltage operation and increased device integration requires specialized test capabilities able to extend across the wide operating ranges found in automotive applications. Among these capabilities, automotive test requirements increasingly dictate a need for a cost-effective versatile mixed-signal pin electronics with very high data rates reaching up to 50MHz with a voltage swing of-2 V to +28 V.     

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.     

Critical Stage Rule-Based Real Time Dispatch（RTD）System in Highly-Mixed-Products （HMP） FAB

An improving utilization and efficiency of critical equipments in semiconductor wafer fabrication facilities are concerned. Semiconductor manufacturing FAB is one of the most complicated and cost sensitive environments. A good dispatching tool will make big difference in equipment utilization and FAB output as a whole. The equipment in this paper is In-Line DUV Scanner. There are many factors impacting utilization and output on this equipment group. In HMP environment one of the issues is changing of reticule in this area and idle counts due to load unbalance between equipments. Here we'll introduce a rule-based RTD system which aiming at decreasing the number of recipe change and idle counts among a group of scanner equipment in a high-mixed-products FAB.     

Optical vibration and deviation measurement of rotating machine parts

It is of interest to get appropriate information about the dynamic behaviour of rotating machinery parts in service. This paper presents an approach of optical vibration and deviation measurement of such parts. Essential of this method is an image derotator combined with a high speed camera or a laser doppler vibrometer （LDV）.