BOARD-LEVEL BUILT-IN SELF-REPAIR METHOD OF RAM

This paper describes the method of built-in self-repairing of RAM on board,designs hardware circuit,and logic for the RAM's faults self-repairing system based on FPGA.The key technology is that it util...     

基于双口RAM核监测数字示波器设计研究

在核监测中,常将各种传感器输出的信号通过A／D转换器转换为数字信号,然后利用数字信号处理技术对各种核信号进行数字处理。为了准确测量核信号数字波形的各种参数,对基于FPGA双口RAM的数字示波器进行了设计和测试分析。实验表明,该数字示波器能准确获取核信号的数字波形及各种参数的值,可对核信号的波形进行录制、回放和精确分析,为核监测及其仪器准确设计提供有力的保证。     

Agitation of Herschel–Bulkley fluids with the Scaba–anchor coaxial mixers

The design of the coaxial mixers depends on many interrelated parameters including the geometry and dimensions of the mixing vessel, the location and type of the impellers, speed ratio, impeller diameter, rotation mode, and fluid rheology. No study has been reported in the literature regarding the mixing performance of the coaxial mixers in the agitation of yield-pseudoplastic fluids. Thus, the main objective of this study was to evaluate the performance of a Scaba–anchor coaxial mixer (a novel configuration) in the mixing of xanthan gum solutions (yield-pseudoplastic fluids). The Herschel–Bulkley model was used to describe the rheological behavior of the xanthan gum solutions. To develop new correlations for the generalized Reynolds and power numbers of the coaxial mixers employed in the agitation of this class of non-Newtonian fluids, we utilized numerous experimental and computational fluid dynamics (CFD) data. The new correlations were tested successfully at different operating conditions (e.g. speed ratio, fluid rheology, and operation mode).     

多层压电结构中声表面波特性的计算

The propagation properties of the surface acoustic waves(SAWs) in a ZnO-SiO2-Si multilayered piezoelectric structure are calculated by using the recursive asymptotic method.The phase velocities and the electromechanical coupling coefficients for the Rayleigh wave and the Love wave in the different ZnO-SiO2-Si structures are calculated and analyzed.The Love mode wave is found to be predominantly generated since the c-axis of the ZnO film is generally perpendicular to the substrate.In order to prove the calculated results,a Love mode SAW device based on the ZnO-SiO2-Si multilayered structure is fabricated by micromachining,and its frequency responses are detected.The experimental results are found to be mainly consistent with the calculated ones,except for the slightly larger velocities induced by the residual stresses produced in the fabrication process of the films.The deviation of the experimental results from the calculated ones is reduced by thermal annealing.     

Preparation of SrBi2Ta2O9 ferroelectric thin film by rf magnetron sputtering

Abstract

SrBi₂Ta₂O₉ (SBT) thin films were deposited on 6-inch Pt/Ti/SiO₂/Si substrates by rf magnetron sputtering using a 12-inch ceramic SBT single target. It is found that several sputtering parameters such as argon (Ar) pressure and rf power were very effective to control the Bi content of SBT thin films which is essential for obtaining good ferroelectric properties.     

Plasma Etch Processes for Embedded FRAM Integration

We describe the etch processes used for integration of embedded ferroelectric random access memory (FRAM) within a standard CMOS logic flow. The ferroelectric module is inserted following front-end contact formation and prior to backend integration using only two additional mask levels: capacitor pattern and bi-level via pattern. The single-mask stack etch process employs a TiAlN hardmask to define Ir/IrO_x/PZT/IrO_x/Ir capacitors. Protective sidewalls can be formed using an etchback process. The bi-level via etch and subsequent metal fill processes complete the FRAM module formation. Functional 4 MB arrays embedded with 5 levels of Cu/FSG integration have been demonstrated.     

Advances in Etching High-Density Embedded FRAM Structures

The development of ferroelectric random access memories (FRAM) has been a sustained endeavor among semiconductor manufacturers over the past decade in response to the growing communications and consumer electronics demand for nonvolatile memories capable of high-speed/low-voltage operation. Process technology and materials performance improvements have refined cell structure, device density, operating voltage, endurance, and data retention. Similarly, advances are being made in etch technology to enable the patterning of true high-density, electrically sound FRAM capacitor arrays. This paper addresses enhancements in chamber design and etch chemistry that have significantly improved electrical performance of the capacitors and achieved sustained stability of the etch process.     

AN HSPICE MACROMODEL FOR RESISTIVE RANDOM ACCESS MEMORY CELL BASED ON CuxO SYSTEM

ABSTRACT

A general HSPICE macromodel for the Cu_xO based resistive random access memory(ReRAM) cell is presented in this paper. It can simulate both the dc and transient behavior of ReRAM cells. The simulation results were compared with the experimental results and exhibited desirable accordance.     

微型数控铣床开发平台运动控制卡的设计

根据开放式系统的设计理念,开发了微型数控铣床的运动控制卡系统。首先,对运动控制卡的功能及硬件结构进行详细设计;然后,根据功能需求将控制卡分成DSP系统、主轴电动机控制系统、XYZ轴步进控制系统及双端口RAM通讯系统进行详细设计;最后,根据设计原理完成控制卡的PCB图和电路板的设计加工调试工作。该运动控制卡已在微型数控铣床开发平台上实验成功,其设计方法对今后运动控制系统的设计具有较高的参考价值。