发射极-基极-发射极结构PNP型AlGaAs/GaAs HBT电流增益的理论分析

建立了PNP型异质结双极晶体管基区少数载流子浓度的解析模型.理论分析了发射极-基极-发射极布局的PNP型HBT的电流增益.讨论了不同基极电流成分,如外基区表面复合电流,基极接触处的界面复合电流,基区体内复合电流,以及刻蚀台面处的台面复合电流对电流增益的影响.     

发射极-基极-发射极结构PNP型AlGaAs/GaAsHBT电流增益的理论分析

建立了 PNP型异质结双极晶体管基区少数载流子浓度的解析模型 .理论分析了发射极 -基极 -发射极布局的PNP型 HBT的电流增益 .讨论了不同基极电流成分 ,如外基区表面复合电流 ,基极接触处的界面复合电流 ,基区体内复合电流 ,以及刻蚀台面处的台面复合电流对电流增益的影响     

发射极-基极-发射极结构PNP型AlGaAs/GaAs HBT电流增益的理论分析

建立了PNP型异质结双极晶体管基区少数载流子浓度的解析模型。理论分析了发射极－基极－发射极布局的PNP型HBT的电流增益。讨论了不同基极电流成分,如外基区表面复合电流,基极接触处的界面复合电流,基区体内复合电流,以及刻蚀台面处的台面复合电流对电流增益的影响。     

Ge组分对SiGe HBT直流特性的影响

制作了基区Ge组分分别为0.20和0.23的多发射极指数双台面结构SiGe异质结双极型晶体管(HBT)。实验结果表明,基区Ge组分的微小增加,引起了较大的基极复合电流,但减小了总的基极电流,提高了发射结的注入效率,电流增益成倍地提高。Ge组分从0.20增加到0.23,HBT的最大直流电流增益从60增加到158,提高了约2.6倍。     

精细的几何图形改进微波双极晶体管的性能

休利特—派卡公司采用精细的几何图形制出了亚微米发射极条,制出了频率高、增益大而又保持噪声低的 HXTR6101器件,其性能是在4千兆赫下,增益为9.0～9.5分贝,典型噪声系数为2.3～2.7分贝。休利特—派卡公司的这种技术,包括离子注入、局部氧化、计算机辅助设计以及自对准工艺。采用制造精细图形的关键工艺—离子注入和自对准技术,在二氧化硅层上同时制做发射极和基极接触窗口。自对准技术可消除最苛刻的对准和硅双极晶体管中的二个主要噪声源:基极扩展电阻中的热噪声和跨越发射极和基极结注入电流中的散粒噪声。作者宣称,要提高这种器件的增益,必须把集电极—基极结电容和集电极—基极键合区     

射频晶体管3DG2714基极电阻R_(bb’)的分析与研究

射频晶体管具有高的特征频率fT,高的功率增益GP。为此在工程上多采用浓硼扩散形成嫁接基区。尽可能减少基极电阻Rbb’,同时采用梳状结构电极,浅结扩散,小的结面积等工艺,提高fT,从而双方面提高功率增益GP。文章以该公司生产的射频晶体管3DG2714为例,分析了发射结下基区部分电流流动状态,合理计算了这部分的基极电阻Rb1,分析了发射极与基极之间淡硼扩散区的电流流动状态,合理计算了这部分的基极电阻Rb2,忽略了两个影响极小的电阻,计算了总的基极电阻Rbb’。为减小基极电阻提高功率增益的射频晶体管设计制造提供了依据。     

I~2L晶体管的基极电流

对于I~2Lnpn晶体管来说,介绍了允许将基极电流分成不同成分的方法:在氧气化层和金属复盖的Fp区中电子的复合电流,在高掺杂n~+发射区中空穴复合电流以及流到P型衬底的空穴漏电流。在固定发射极—基极电压时对不同几何形状的IL器件基极电流进行了比较。讨论了几种预防寄生效应的措施。在540～650ml的发射极—基极电压范围内进行了测量,不同的基极电流密度被表示为外加的发射极—基极电压的一个函数。对所测得的电流密度推导出数学表达式并与理论相比较。文章指出为了解释实验值和理论值之间的差异,器件处于重掺杂范围时应考虑到禁带宽度变窄的影响。此外,它表明实验测定的四个集电极I~2L门的基极电流与计算值能很好地相符。对这个门来说,电子复合电流仅仅是基极电流的20%,而空穴复合电流是基极电流的主要成分。     

非晶态发射极晶体管(FFJ)

采用非晶态硅作为双极型微波功率晶体管的发射极材料,利用这种硅层的垂直电阻的镇流作用,能够消除发射极边缘的注入电流集边现象。与通常晶体管相比,FFJ的有效发射极面积对基极面积之比值提高2～3倍,输出功率-阻抗乘积提高5～10倍。 由于FFJ的发射极-基极结电容仅仅取决于它的发射极掺杂情况,因此,可以同时得到较小的基极电阻r_b和较高的发射极截止频率f_(TE)。f_(max)的数值可以比通常的晶体管高3～5倍。     

用于低电压、宽带CDMA的HBT功率放大器

据《信学技报》(日)2010年109-361期报道,日本三菱电机高频光器件制作所开发了用于低电压、宽带CDMA的HBT功率放大器。HBT的主要特性为:DC电流增益100 typ,基极集电极耐压22 V,集电极发射极耐压15 V,基极集电极二极管等价直流阻抗6Ω(4 mA/100μm~2电流时)。该功率放大器在频率824 MHz、输出功率28 dBm时,功率增益27.7 dB,邻沟道泄漏功率抑制比-50.5 dBc,功率附加效率36%;在频率925 MHz时,功率增益27.5 dB,邻沟道泄漏功率抑制比-51.3 dBc,功率附加效率36%。其工作温度范围为-20～+85℃。     

无偏置源的多谐振荡器

普通等待式的多谐振荡器,为保持其中一个晶体管截止,要求有偏置电压(图a).在晶体管BG_1的基极接一个二极管D_1,可不用偏置源(图b).当电路处于静态时,供给BG_1基极电流唯一的电压是导通管BG_2的集电极-发射极饱和电压.这电压为激起通过BG_1的基极的电流是太小了,因BG_1的基极-发射极     

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.     

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.     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first