模拟集成电路新技术

近几年来,模拟集成电路得到了飞速发展,其表现之一是使用MOS器件的模拟集成电路逐渐成为主流,改变了模拟集成电路主要使用双极型器件的局面。MOS器件具有尺寸小、功耗低等优点,特别是它与数字电路的主流工艺兼容,这对系统级芯片(SOC)的实现有重要意义。而MOS器件的噪声大,工作频率低的缺点,随着集成电路工艺和电路技术的进步,已有很大改观,完全可以满足一般电子系统对性能的要求。     

MOS晶体管失配模型研究及应用

采用0.18μm CMOS工艺,研究在模拟集成电路中MOS管的失配.通过分析MOS管在饱和区失配因素,优化MOS管失配模型,提出用最小二乘曲线拟合法进行相关模型参数提取.并根据这些参数对基本电路的失配进行预测和分析,给出改善MOS管匹配性的方法.这为相应的集成电路设计中存在的失配提供了理论依据.     

模拟电路设计中匹配器件组版图自动生成技术

目前,大多数模拟版图设计者采用人工方式分析电路图、查找匹配器件组,从而进行手工布局.在大规模集成电路设计中,为了缩短集成电路的设计周期,降低成本,利用C++语言算法开发一款模拟集成电路版图布局自动化的工具.针对模拟电路中匹配器件组的匹配模式不同,根据每种匹配模式的特点编写了相应匹配器件组自动布局的算法,缩短版图的布局时间,从而缩短了设计周期,降低设计成本.通过对每种匹配模式的模拟测试及结果分析,验证了该算法的可行性和有效性.     

功率集成电路TID加固环栅器件研究现状综述

总结了标准工艺下功率集成电路中总剂量辐射(TID)加固环栅MOS器件与环栅功率器件的研究现状,归纳了不同结构形态的环栅器件的性能优劣,推荐8字形环栅MOS器件、华夫饼功率器件及回字形LDMOS器件结构用于功率集成电路的TID加固设计。同时,阐述了现有环栅MOS器件等效W/L的建模情况,提出保角变换是环栅MOS器件等效W/L精确建模的重要方法,最后还给出了环栅器件建库的基本流程。     

差分放大器中的不匹配效应及消除方法

叙述模拟集成电路设计中关于MOS管不匹配特性的一些基本概念,以及随着加工尺寸的不断减小,MOS管所引起的一系列短沟道效应,进而描述整个MOS管模型的发展历史,以此说明一个精确模型对模拟电路设计的重要意义.然后进一步阐述因MOS管失配而引起电路性能变差,尤其是对整个D/A转换器性能的影响;进而采用改进技术,并对其进行了进一步验证.针对放大器引起的失调,介绍通过版图设计消除失配的原理,并且运用电路设计方法进行消除,采用TSMC0.25μm标准CMOS工艺参数对其进行仿真验证.针对D/A的电流源失配引起的电路性能变差,采用了电流源自校准技术,并对这种方法进行了仿真验证,取得了不错的成果.     

SiO_2中电子束辐照产生的电子陷阱

<正> SiO_2中的陷阱在MOS短沟道器件的设计中是一重要限制,随着MOS集成电路集成度的提高,器件尺寸的缩小,必须考虑器件的热电子效应,SiO_2中陷阱的存在使热电子注入后器件性能发生变化,严重影响器件的稳定性、可靠性,另外电子束曝光、离子刻蚀、     

B样条函数在短沟道MOS器件直流特性模拟中的应用

本文提出了采用B样条函数模拟MOS器件直流特性的新方法。基于“张量积”原理和重结点技巧,推导出满足MOS器件边界约束条件的三维二次B样条函数最小二乘法的数学模型,并开发了相应的 SMDC程序(Simulation for MOS DC Characteristics). 该程序对沟道长度分别为 8、5、3和 0.39μm的MOS器件直流特性的模拟结果表明,所有器件的计算值与测量值相符得很好,在器件的工作范围内,全部数据的平均相对误差只有2％左右.在IBM370/148机器上运行SMDC程序时,计算一个I_(DS)数据的CPU时间为0.1秒. 与集成电路通用模拟程序SPICE中的MOS解析模型相比较,SMDC程序在模拟短沟道MOS器件、尤其是沟道长度小于1μm的亚微米器件的直流特性的精度方面,具有明显的优越性.     

初学者知识园地

它是以金属—氧化物一半导体场效应晶体管为主体构成的集成电路,简称为MOS集成电路。以N型沟道MOS晶体管构成的集成电路,称为N沟MOS集成电路,以P型沟道MOS晶体管构成的集成电路称为P沟MOS集成电路,二者统称单沟MOS电路。 N沟器件的多数载流子是电子,P沟器件的多数载流子是空穴。场效应器件是多数载流子工作的器件,电子比空穴的有效质量小,迁     

High-k材料MOS器件的PISCES-II模拟

High-k材料是指介电常数k高于SiO2的材料。使用high-k材料做栅绝缘层,是减小MOS器件栅绝缘层直接隧道击穿(DirectTunneling,DT)电流的有效方法。文章在二维器件模拟软件PISCES-II中添加了模拟以high-k材料为栅绝缘层的MOS器件模型,并对SiO2和high-k材料的MOS晶体管器件特性进行了模拟比较,成功地验证了所加high-k材料MOS器件模型的正确性。改进后的PISCES-II程序,可以方便地对以各种high-k材料为栅绝缘层的器件性能进行模拟。     

浅谈CMOS模拟集成电路版图设计的器件匹配方法

基于模拟集成电路版图设计中的器件不匹配问题,对版图设计中的器件匹配的方法、技巧以及需要注意的问题进行总结,并结合一个运放的版图设计实例详细阐述了版图设计的基本器件匹配方法与技巧。     

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.     

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.     

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.     

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.     

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.