砷化镓微波单片集成电路的失效分析

通过封装内部气氛、芯片显微、能谱等分析手段对国内某研究所研制砷化镓微波单片集成电路高温加速寿命试验后的样品进行了失效分析,对其失效机理进行探讨,得出:封装气密性不好、工艺造成的缺陷是引起失效的主要原因,也是造成国内产品质量与可靠性不如国外同类产品的重要原因。     

Collinear acoustooptical interaction in annealed proton-exchanged LiNbO_3 waveguides

The performances of the proto-exchanged(PE) LiNbO_3 waveguides as a key ele-ment of acoustooptical deflector or spectrum analyzer were distinctly improved after anneal-ing.In this paper,reasons for the improvement are analysed by applying the theories of modecoupling and multilayer waveguides,so as to provide a theoretical basis for further improve-ment of the performances of the devices.     

Damage to n-MOSFETs from electrical stress Relationship to processing damage and impact on device reliability

The study reported herein examines and compares damage to n-channel and p-channel metal-oxide-silicon field-effect transistors (MOSFETs) from direct current (d.c.) and alternating current (a.c.) electrical stresses as well as the relationship of this damage to plasma processing damage in MOSFETs. The lightly-doped drain (LDD) MOSFETs used are of 0.5 μm channel length and with a 90 Å thick thermally grown gate oxide fabricated using a full flow CMOS process up to and including metal-1 processes and post-metallization annealing (PMA). The damage to MOSFETs is assessed using transistor parameter characterization and charge-to-breakdown measurements on the gate oxide. It is found that manifestations of d.c. stress-induced damage and a.c. stress-induced damage to transistors are fairly similar in that both forms of damage are passivated by PMA and are reactivated by a subsequent d.c. electrical stress. However, a.c. stress-induced damage is observed to occur at much lower electric fields across the gate oxide than those necessary for d.c. stress-induced damage to be significant. This is attributed to a.c. currents, caused by carrier hopping, occurring at relatively low electric fields. One implication of our results is that plasma-charging damage, often attributed to d.c. electrical stress alone, may comprise an a.c. electrical stress component too.     

跨越不同容量设置DWDM网络的动态IP/DWDM综合路由算法研究

IP/DWDM网络的综合路由中的一个重要的研究问题就是如何对跨越不同DWDM网络的IP路由进行综合路由,特别是当两个DWDM网络的容量设置不同时。本文着重解决的就是如何对从单波长带宽大的网络进入单波长带宽小的网络传输的IP业务的综合路由问题。根据尽量鼓励对波长链路的带宽进行完全使用,以减小波长链路带宽碎片的原则,我们提出了两种解决算法:1 n 算法和 m n算法。仿真结果对两种算法的效率和性能进行了测试。     

宽带综合业务数字网的ATM技术

目前宽带综合业务数字网(B—ISDN)已成为各国研究与开发的重要内容。本文简述了信息传输技术的发展趋势,着重介绍了ATM技术的概念、ATM信元结构和传输帧结构、ATM交换技术和ATM系统参考模型。     

IMPROVED GENERALIZED ADMITTANCE MATRIX TECHNIQUE AND ITS APPLICATIONS TO RIGOROUS ANALYSIS OF MILLIMETER-WAVE DEVICES IN RECTANGULAR WAVEGUIDE

An improved generalized admittance (GAM) matrix technique is presented in this paper. Matrix transformation eliminates the singularity factor of GAM, denominator (1+Γ), because of new presentations of GAM. The relationship equations between II-port current and I-port incidence wave is computed by mode matching method. The generalized scattering matrix (GSM) of waveguide structure and its discontinuity problems is obtained with relationship equations and reflection coefficients. The GSM’s of millimeter-wave multistepped bend and T-junction in rectangular waveguide are computed by the improved GAM technique. The results comparisons between the proposed method and commercial software HFSS10.0 show the validity of the proposed method, which improves the validity of the GAM technique and reduces mathematical efforts. It is general, very efficient and can be used to solve other complicated and multiport network problems.     

Monolithically integrated HgCdTe focal plane arrays

The cost and performance of hybrid HgCdTe infrared (IR) focal plane arrays are constrained by the necessity of fabricating the detector arrays on a CdZnTe substrate. These substrates are expensive, fragile, available only in small rectangular formats, and are not a good thermal expansion match to the silicon readout integrated circuit. We discuss in this paper an IR sensor technology based on monolithically integrated IR focal plane arrays that could replace the conventional hybrid focal plane array technology. We have investigated the critical issues related to the growth of HgCdTe on Si read-out integrated circuits and the fabrication of monolithic focal plane arrays: (1) the design of Si read-out integrated circuits and focal plane array layouts; (2) the low-temperature cleaning of Si(001) wafers; (3) the growth of CdTe and HgCdTe layers on read-out integrated circuits; (4) diode creation, delineation, electrical, and interconnection; and (4) demonstration of high yield photovoltaic operation without limitation from earlier preprocessing such as substrate cleaning, molecular beam epitaxy (MBE) growth, and device fabrication. Crystallographic, optical, and electrical properties of the grown layers will be presented. Electrical properties for diodes fabricated on misoriented Si and readout integrated circuit (ROIC) substrates will be discussed. The fabrication of arrays with demonstrated I–V properties show that monolithic integration of HgCdTe-based IR focal plane arrays on Si read-out integrated circuits is feasible and could be implemented in the third generation of IR systems.     

LiNbO3质子交换波导及其退火效应

采用质子交换技术,以苯甲酸为交换源,实验研究X-切LiNbO₃质子交换平面波导及其退火效应。利用棱镜耦合器测出波导模折射率。采用费米函数,由模折射率确定出波导折射率分布随退火时间的变化关系,给出了分布参数和曲线.     

波导管中高压氢气受激拉曼散射特性研究

本文研究了波导管中准分子激光泵浦高压氢气的高效受激拉曼散射特性,并从理论上分析了采用波导结构后转换效率提高的原因。     

Solvent detection using porous silicon optical waveguides

Since the first report on the use of porous silicon as an optical waveguide medium in 1995, significant development has been made towards the understanding and applicability of such material. Here, the introduction of solvents (acetone, methanol, and propan-2-ol) into the pores is shown to dramatically reduce the loss of the waveguides, in a reversible manner. Both the magnitude and duration of this effect are sensitive to the solvent introduced. In some waveguides, for example, the measured loss (at 0.633 μm) falls by as much as 34 dB cm⁻¹ on the introduction of acetone. Theoretical estimates of the effect of solvents on the interfacial scattering loss confirm this as the origin of the observed reductions. These results, combined with the fact that a substantial portion of the guided-mode field interacts with the solvent, indicate an enhanced sensitivity for sensor applications may be achievable.