Improved bipolar transistor performance in a VLSI CMOS process

Bipolar n-p-n transistors have been successfully fabricated on a high-performance n-well VLSI CMOS process incorporating an additional mask and implant step. A double active-base implant was utilized to control the base surface concentration and the transistor characteristics separately. High forward common-emitter current gain and collector-emitter breakdown voltage can be achieved by this process. n-p-n transistors with βf= 100, BVCE0= 9.0 V, and BVCB0= 23 V can be easily fabricated on this scaled VLSI CMOS process.     

Improved 2D joint process lattice for adaptive restoration ofimages

An improved method to obtain the 2D joint process lattice structure using recently developed 2D orthogonal quarter-plane filters for AR modelling is reported. It is shown that a set of orthogonal backward prediction error fields can be used to calculate the corresponding joint process coefficients     

Improved SRAM failure diagnosis for process monitoring via current signature analysis

SRAM's are frequently used as monitor circuits for defect related yield, due to the ease of testing and the good correlation to the yield characteristics of logic circuitry. For the identification of the failure/fault type and the nature of the defect causing the failure, measured failbitmaps are mapped onto a failbitmap catalog obtained from defect-fault simulation. Often this mapping is not unique. A given failbitmap can be caused by several faults or defects.In this contribution, the application of current signature analysis is demonstrated for a stand-alone 16kx1 SRAM monitor circuit. It is found that the resolution of the failbitmap-fault-defect catalog can be improved considerably by additional current signature measurements. The interpretation of current measurements is based on simulation of the possible faults contained in the failbitmap catalog under the operating conditions in the current test. There was good agreement between the simulated and measured current values.With the aid of current measurements, more yield learning information is obtained from the process monitoring vehicle. In some cases, the shorted nodes inside a SRAM cell can be determined exactly. This eases the localization of the failure and is of practical importance for the sample preparation in physical failure analysis.     

基于改进层次分析法的动力定位系统综合评价

文章从分析动力定位系统的体系结构入手建立系统评价的指标体系,即将测量效能、控制效能和推力效能3方面作为动力定位系统效能的第一层准则;位置参考系统可靠性、数据处理与融合能力、原动机功率转化能力等作为第二准则层。文章针对动力定位系统的效能评估工作,采用了改进的层次分析法为评估算法,以某耙吸式挖泥船为研究对象进行评估,最后评估结果与实际运行情况相符,验证了方法的可行性和有效性。     

Improved manufacturability of ZrO2 MIM capacitors by process stabilizing HfO2 addition

A broad compositional range of the dielectric material Zr_1?xHf_xO₂ was evaluated with respect to its applicability in DRAM storage capacitors. The paper reports on phase composition, crystallization behavior, and electrical properties of the mixed system in planar metal-insulator-metal (MIM) capacitors. Admixture of HfO₂ into ZrO₂ proved to stabilize the deposition process at high temperatures without degrading the dielectric properties of the film. Compared to pure ZrO₂ the 30–40% HfO₂ containing films showed improved scalability (capacitance equivalent thickness 0.73 nm at 8 * 10^?9 A/cm²) as well as improved reliability.     

Improved device performances in polymer light-emitting diodes using a stamp transfer printing process

The device performances of spin-coated and stamp transfer printed devices were compared. There was little difference of morphology between the spin-coated and stamp transfer printed devices. However, the stamp transfer printing process was better than the spin-coating process in terms of current density, light-emitting efficiency and lifetime. In particular, the lifetime of the stamp transfer printed device was doubled compared with that of the spin-coated device.     

Improved barium fluoride process YBa2Cu3)7-x films via post-anneal monitoring

The continuous monitoring of the conversion, of Y, Cu and BaF₂ precursors to form superconductor thin films has been achieved using a fluorine-specific-ion electrode immersed in an effluent gas-washing cell. High-quality thin films of YBa₂Cu₃O_7-x deposited on NdGaO₃, LaA10₃ and LaGaO₃, have been produced by limiting the wet oxygen annealing phase of the post-deposition anneal. When the films were over-annealed in humidified oxygen the superconducting transition temperature as measured by inductive methods and the crystal quality, determined by x-ray rocking curves were degraded.     

Improved NiSi salicide process using presilicide N/sub 2//sup +/ implant for MOSFETs

An improved Ni salicide process has been developed by incorporating nitrogen (N/sub 2//sup +/) implant prior to Ni deposition to widen the salicide processing temperature window. Salicided poly-Si gate and active regions of different linewidths show improved thermal stability with low sheet resistance up to a salicidation temperature of 700 and 750/spl deg/C, respectively. Nitrogen was found to be confined within the NiSi layer and reduced agglomeration of the silicide. Phase transformation to the undesirable high resistivity NiSi/sub 2/ phase was delayed, likely due to a change in the interfacial energy. The electrical results of N/sub 2//sup +/ implanted Ni-salicided PMOSFETs show higher drive current and lower junction leakage as compared to devices with no N/sub 2//sup +/ implant.     

Improved efficiency of multicrystalline silicon solar cells by TiO2 antireflection coatings derived by APCVD process

This paper reports about the adaptation of the chemical vapor deposition (CVD) thin films technology to the fabrication process of multicrystalline silicon solar cells as a simple, low cost and very effective technology for efficiency device improvement by reducing reflection and improving the light-generated current. In this contribution, the higher reflection of a mc-Si solar cell surface is strongly reduced by the deposition of TiO₂ antireflection coating (ARC) on the front using the atmospheric pressure chemical vapor deposition method (APCVD). The surface morphology and elemental composition of the TiO₂ antireflective layers were revealed using scanning electron microscopy in conjunction with energy dispersive X-ray spectroscopy . The reflectivity was then reduced from 35% to 8.6% leading to the increase of the short circuit current J_sc which was 33.86 mA/cm² with a benefit of 5.23 mA/cm² (surface area=25 cm²) compared to the reference cell (without ARC). This simple and low cost technology induces a 14.26% conversion efficiency which is a gain of +3% absolute in comparison to the reference cell. The LBIC measurements of a typical multicrystalline cell confirmed the uniformity of the photocurrent distribution throughout the device. These results are encouraging and prove the effectiveness of the APCVD method for efficiency enhancement in silicon solar cells.     

Improved spectral resolution

Two new methods are presented for the estimation of the frequencies of closely spaced complex valued sinusoidal signals in the presence of noise. The most effective method is a computationally efficient method for realization of maximum likelihood or maximum posterior probability estimates of the frequencies. The second method is a class of algorithms for removing some of the deficiencies of present adaptive filtering and correlation-estimation approaches to estimation of frequencies, such as the forward-backward linear prediction method. In both of these new methods one is fitting a signal model to data. In method 1 the data are the observed samples of two complex sinusoids plus noise. In the second method the data are elements of an estimated correlation matrix, or of some of its eigenvectors, obtained from the observed samples.     

Improved Feedback Theory

A previous cut-insertion theorem for linear circuits and its application to a generalization of the elementary feedback theory are further extended. The new theorem is based on the splitting of an arbitrary node into two nodes and on the insertion between them and another arbitrary ldquoreferencerdquo node, of a three-terminal circuit which keeps the network currents and voltages unchanged. The system analysis is in turn performed on the equivalent cut network by means of the techniques for two-port circuits, using generic variables, i.e., either voltages or currents. The new approach allows one to define a two-port circuit as an open loop around the split and reference nodes, as well to define a new feedback model specifically focused on it. Furthermore, it allows one to retrieve all the results of the previous general feedback theories, as well as several new ones. The obtained expressions of the overall transfer function include, as a particular case, the Blackman formula for the immittances, and relationships without the leakage term, which are useful for circuit synthesis and for dealing with spurious signals. New expressions are proposed for the evaluation of the output and input immittances. The virtual short-circuit method is derived and numerical and design examples are provided. The new approach retains the intuitive feedback vision of the elementary models.     

Improved ICT Infrastructure

The global WAN infrastructure originally followed the hierarchical structure in the telephony networks. The present evolution is going in the direction of uncoordinated loosely coupled ad hoc networks without an overall commonly agreed upon architecture. The convergence towards a unified global WAN platform, providing a comprehensive set of services spanning from best effort to guaranteed high quality services, sets the agenda for the design and implementation of the next generation Global Information Infrastructure. These problems were presented and discussed during the Extraordinary Brainstorming Panel: “EC FP7 Call 5” at the SW09 at Rebild, Denmark, May 15–17, 2009. There was a general consensus on the need for initiatives to ensure an improved and needed long term evolution towards a more well organized and structured approach to identify the key parameters for a new global ICT Infrastructure Reference Architecture. This paper reflects some of the elements of the discussions, some examples presented and some initiatives taken in order to follow up on the conclusions.     

改进型Quasi-Z源逆变器

传统Z源逆变器通过自身特殊的阻抗网络实现升压功能,而不需要加入升压斩波电路,使得Z源逆变器得到了广泛的应用。但是传统Z源逆变器的升压能力有限,且存在启动冲击电流问题。为了克服传统Z源逆变器的不足,提出一种改进型Quasi-Z源逆变器拓扑结构,以改善逆变器的工作性能。改进型Quasi-Z源逆变器有效提高了逆变器的升压能力,使其可以适用于需要高增益的场合,在理论研究的基础上,通过Matlab/Simulink仿真验证了改进型Quasi-Z源逆变器拓扑结构的可行性和优越性。     

Improved morphological top-hat

An improved morphological top-hat transform is presented which offers improved detection of light or dark image blobs in the presence of certain types of noise     

Improved Nyquist pulses

In this letter, we propose two new Nyquist (intersymbol interference free) pulses that exhibit better error probability performance in the presence of sampling errors than the popular raised-cosine and a recently proposed pulse by Beaulieu, Tan, and Damen. The new pulses are also robust to the root and truncation operations.     

一种改进的Woo-Lam协议

串空间是一种基于定理证明的,新兴的安全协议形式化分析模型.认证协议使用密码技术实现网络环境下的身份认证和信息保密.本文针对Woo-Lam协议的不足,对其进行改进,提出了一种新的Woo-Lam协议,使其成为双向认证协议,并基于串空间模型,然后对改进的Woo-Lam协议进行分析证明,结果证明了改进的Woo-Lam协议为双向认证协议.最后通过比较了改进前后的Woo-Lam协议,得出了结论.     

Improved microwave-transistor structure

An improved microwave-transistor structure, in which the active and inactive base regions are formed by separate processes, is described. In this structure, a low base resistance is obtained by the use of a heavily doped inactive base region, which has a low sheet resistance and which also, by lateral diffusion, reduces the effective width of the emitter. At the same time, the active base region, formed by ion implantation, is separately optimised to improve the current-gain cutoff frequency. Transistors with the improved structure have noise factors of 2.3 dB at 4 GHz, compared with 3.6 dB for transistors with the same geometry but fabricated by the conventional double-diffusion process.