薄栅氧化层0.25μm RF PDSOI NMOSFETs电离总剂量辐照效应研究

本文研制了一种与0.1μm SOI CMOS工艺兼容的射频PD SOI NMOSFET,并分析了电离总剂量辐照对四种不同结构射频器件的静态特性和频率特性的影响,分别包括前/背栅阈值、泄漏电流、跨导,输出特性以及交流小信号电流增益和最大有效/稳定增益。实验表明,在室温环境下经过总剂量为1Mrad(Si)的g射线辐照,所有的射频PDSOI NMOSFET的静态和射频特性均表现出明显退化,其中以浮体NMOSFET变化最大。虽然损失了部分驱动电流、开关速度和高频特性,LBBC型体接触结构的射频器件仍表现出优于GBBC和BTS型体接触结构的射频器件的抗电离总剂量辐照的能力。     

RF PDSOI LDMOS器件的电离总剂量辐照效应

研制了一种用于射频领域的叉指栅PDSOI LDMOS晶体管,并分析了总剂量辐照对其静态和小信号射频特性的影响. 其静态工作模式下的辐照响应由前/背栅阈值、泄漏电流、跨导和输出特性表征,而其交流工作模式下的辐照响应由截止频率和最高振荡频率表征. 实验表明,在室温环境下经过总剂量为1Mrad(Si)的γ射线辐照,不同尺寸和结构的射频SOI LDMOS晶体管的各项指标均表现出明显退化,并且仅当器件工作在静态模式时LBBC LDMOS才表现出优于BTS LDMOS的抗辐照性能.     

RF PDSOI LDMOS器件的电离总剂量辐照效应

研制了一种用于射频领域的叉指栅PDSOI LDMOS晶体管,并分析了总剂量辐照对其静态和小信号射频特性的影响.其静态工作模式下的辐照响应由前/背栅阈值、泄漏电流、跨导和输出特性表征,而其交流工作模式下的辐照响应由截止频率和最高振荡频率表征.实验表明,在室温环境下经过总剂量为1Mrad(Si)的γ射线辐照,不同尺寸和结构的射频SOI LDMOS晶体管的各项指标均表现出明显退化,并且仅当器件工作在静态模式时LBBC LDMOS才表现出优于BTS LDMOS的抗辐照性能.     

PDSOI 静态随机存储器的总剂量辐照加固

对PDSOI CMOS 器件及电路进行总剂量辐照的加固势必会引起其性能下降,这就需要在器件及电路加固和其性能之间进行折中.从工艺集成的角度,对PDSOI CMOS器件和电路的总剂量辐照敏感区域:正栅氧化层、场区氧化层及埋氧层提出了折中的方法.采用此种方法研制了抗总剂量辐照PDSOI SRAM ,进行总剂量为2×105 rad(Si)的辐照后SRAM的各项功能测试均通过,静态电流的变化满足设计要求,取数时间:辐照前为26.3 ns;辐照后仅为26.7 ns.     

部分耗尽DTMOS的模拟和射频特性研究

基于0.35μm部分耗尽SOI CMOS工艺技术平台,我们实现了一种H栅型PDSOI动态阈值MOS晶体管。通过比较H栅型PDSOI动态阈值NMOS和传统PDSOI H栅NMOS的模拟和射频特性,我们深入研究了此类H栅型PDSOI动态阈值NMOS不同于其他H栅MOS器件的工作原理和物理机制。实验结果表明,此类H栅型PDSOI动态阈值NMOS在栅源电压为0.7V和漏源电压为1V的情况下,可获得40GHz截止频率和29.43GHz最大振荡频率。     

SiGe HBT 60Co γ辐照总剂量效应

测量了SiGe HBT直流增益在60Coγ辐照过程中随剂量及器件电流注入水平的变化。实验结果显示在累计辐照剂量超过5 000 Gy(Si)后,器件电流增益变化与辐照剂量存在线性反比关系,且增益损伤系数与器件电流注入水平有关;器件在受到总剂量为2.78×104Gy(Si)辐照后,器件静态基极电流Ib、集电极电流Ic、静态直流增益及最大振荡频率fmax出现不同程度退化;但器件其他电参数如截止频率fT、交流增益|H21|及结电容(CCBO)与辐照前相比未出现显著退化。利用MEDICI数值模拟分析了SiGe HBT参数退化机理。     

抗辐射0.18μm NMOS器件热载流子效应研究

基于0.18μm CMOS工艺开发了抗总剂量辐射加固技术,制备的1.8 V NMOS器件常态性能良好,器件在500 krad(Si)剂量点时,阈值电压与关态漏电流无明显变化。研究器件的热载流子效应,采用体电流Isub/漏电流Id模型评估器件的HCI寿命,寿命达到5.75年,满足在1.1 Vdd电压下工作寿命大于0.2年的规范要求。探索总剂量辐射效应与热载流子效应的耦合作用,对比辐照与非辐照器件的热载流子损伤,器件经辐照并退火后,受到的热载流子影响变弱。评估加固工艺对器件HCI可靠性的影响,结果表明场区总剂量加固工艺并不会造成热载流子损伤加剧的问题。     

源区浅结SOI MOSFET的辐照效应模拟

研究了源区浅结的不对称SOI MOSFET对浮体效应的改善,模拟了总剂量、抗单粒子事件(SEU)、瞬时辐照效应以及源区深度对抗辐照性能的影响.这种结构器件的背沟道抗总剂量能力比传统器件有显著提高,并且随着源区深度的减小,抗总剂量辐照的能力不断加强.体接触不对称结构的抗SEU和瞬时辐照能力优于无体接触结构和传统结构器件,这与体接触对浮体效应的抑制和寄生npn双极晶体管电流增益的下降有关.     

源区浅结SOI MOSFET的辐照效应模拟

研究了源区浅结的不对称SOIMOSFET对浮体效应的改善 ,模拟了总剂量、抗单粒子事件 (SEU)、瞬时辐照效应以及源区深度对抗辐照性能的影响 .这种结构器件的背沟道抗总剂量能力比传统器件有显著提高 ,并且随着源区深度的减小 ,抗总剂量辐照的能力不断加强 .体接触不对称结构的抗SEU和瞬时辐照能力优于无体接触结构和传统结构器件 ,这与体接触对浮体效应的抑制和寄生npn双极晶体管电流增益的下降有关     

抗总剂量Boost型 DC-DC转换器设计

采用设计加固方法,基于标准商业0.35微米CMOS工艺,设计了抗总剂量Boost型 DC-DC转换器芯片。从系统设计角度出发,综合采用了同步整流、高开关频率、自适应动态斜坡补偿等技术提高DC-DC转换器性能和抗辐照能力;分别从电路级和器件级对转换器进行了加固设计。考虑DC-DC转换器总剂量效应,电路级加固分别从模拟电路加固和数字电路加固着手;提高环路稳定裕度,有效的提高转换器反馈环路的抗总剂量能力。为有效的降低场区辐射寄生漏电,器件级采取的加固措施是转换器的控制部分MOS管采用H栅实现,输出功率MOS管采用环形栅实现。辐照实验结果表明,设计的抗总剂量Boost型 DC-DC转换器在总剂量超过120 krad (Si )后才出现功能失效,而非加固的电路在总剂量超过80 krad (Si )后才出现功能失效;加固电路的辐照后电流明显小于非加固电路;加固电路的辐照后效率也高于非加固电路。     

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.     

Development of the readout system for waveguide multilayer optical card

Waveguide multilayer optical card （WMOC） is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling ＆ processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic （VB） language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.     

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.     

A method for calculating the center position of collimated light

It is a key problem to accurately calculate beam spots＇ center of measuring the warp by using a collimated laser. A new method, named double geometrical center method （DGCM）, is put forward for the first time. In this method, a plane wave perpendicularly irradiates an aperture stop, and a charge couple device （CCD） is employed to receive the diffraction-beam spots, then the geometrical centers of the fast and the second diffraction-beam spots are calculated respectively, and their mean value is regarded as the center of datum beam. In face of such adverse instances as laser intension distributing defectively, part of the image being saturated, this method can still work well. What＇s more, this method can detect whether an unacceptable error exits in the courses of image receiving, processing and calculating. The experimental results indicate the precision of this method is high.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems.