Electrical characteristics and TDDB breakdown mechanism of N2-RTA-treated Hf-based high-κ gate dielectrics

This study investigates the effects of rapid thermal annealing (RTA) in nitrogen ambient on HfO₂ and HfSiO_x gate dielectrics, including their electrical characteristics, film properties, TDDB reliability and breakdown mechanism. The optimal temperature for N₂ RTA treatment is also investigated. The positive oxide trap charges (oxygen vacancies) in HfO₂ and HfSiO_x dielectric films can be reduced by the thermal annealing, but as the annealing temperature increased, many positive oxide trap charges (oxygen vacancies) with shallow or deep trap energy level will be formed in the grain boundaries, degrading the electrical characteristics, and changing the breakdown mechanism. We believe that variation in the number of positive oxide trap charges (oxygen vacancies) with shallow or deep trap energy levels is the main cause of the CV shift and difference in the breakdown behaviors between HfO₂ and HfSiO_x dielectrics. With respect to CV characteristics and TDDB reliability, the optimal temperature for N₂ RTA treatment is in the range 500-600 °C and 800-900 °C, respectively.     

栅控二极管正向 R- G电流对 SOI体陷阱特征和硅膜结构的依赖性

使用半导体器件数值分析工具 DESSISE- ISE,对侧向的 P+ P- N+栅控二极管的正向 R- G电流对 SOI体陷阱特征和硅膜结构的依赖性进行了详尽的研究 .通过系统地改变硅膜体陷阱的密度和能级分布 ,得出了相应的 P+ P-N+ 栅控二极管的正向 R- G电流的变化 .同时 ,表征硅膜结构的参数如沟道掺杂和硅膜厚度的变化也使器件从部分耗尽向全耗尽方向转化 ,分析了这种转化对 R- G电流大小和分布的影响     

基于SEOA算法的抽水蓄能梯级水库调度研究

针对含混合式抽水蓄能电站的梯级水库发电调度的维数灾问题,在考虑历史径流序列随机性和非线性特点的基础上,建立含混合式抽水蓄能电站的梯级水库长期优化调度模型。文中以调度期内混合式抽水蓄能电站梯级水库发电量最大为目标函数,引入改进社会情态优化(SEOA)算法编程求解。仿真结果表明,新方法在混合式抽水蓄能电站梯级水库发电优化调度问题中既能减少传统算法的冗余计算,又可有效地结合决策者的主观偏好和利益倾向。对比动态规划算法,新方法在较短时间内得到年发电量为66.96×10 ⁸ kWh的高质量解。     

基于SNMP的带外服务器的研究

分析了基于SNMP协议的网络管理结构及在嵌入式带外服务器中实现SNMP模块的重要性,详细说明了SNMP Agent的工作流程.在原有的基于嵌入式Linux平台的带外管理系统中增加了SNMP模块,增强了该系统的网络可管理性,可以通过网络管理工作站对其进行监控和维护.     

超深亚微米P+栅PMOSFET中NBTI效应及其机理研究

本文深入研究了P⁺栅PMOSFET中的NBTI效应,首先通过实验分析了NBTI应力后器件特性及典型参数的退化,基于这些实验结果提出了一种可能的NBTI效应发生机制:即由水分子参与的Si-SiO₂界面处的电化学反应.最后从工艺的角度给出了减小和抑制NBTI效应的方法.     

SiO_2-Si_3N_4栅介质膜陷阱特性的高频C-V分析

采用高频 C-V特性测试技术 ,研究由热氧化生成的超薄 Si O2 膜和低压化学汽相淀积法制备的非均匀结构 Si3N4膜 ,两者组成的栅介质膜的陷阱特性 (包括陷阱密度、能量和空间分布深度等参数 )。结果表明 :在栅复合膜陷阱电荷非稳态释放模型下建立的高频 C-V理论及其分析方法 ,可以很好地表征实验曲线 ,并获取所需的存储陷阱分布参数     

GaN基MSM结构紫外探测器光响应特性

在求解一维电流连续性方程和传输方程的同时考虑表面态陷阱的作用,获得了GaN基MSM结构紫外探测器在稳态光照下的电流随电压变化的解析解,从而导出了其光响应特性主要参数,并解释了电流和响应度随偏压变化的原因和光增益现象.将该模型应用于具体器件,实验测得饱和临界偏压约6 V,稳态电流6×10-8A,响应率0.085 7 A/W,与理论计算较吻合.     

Snapback应力对90nm nMOSFET栅氧化层完整性的影响

基于测试对snapback应力引起的栅氧化层损伤特性和损伤位置进行了研究.研究发现应力期间产生的损伤引起器件特性随应力时间以近似幂指数的关系退化.应力产生的氧化层陷阱将会引起应力引起的泄漏电流增加,击穿电荷减少,也会造成关态漏泄漏电流的退化.栅氧化层损伤不仅在漏区一侧产生,而且也会在源区一侧产生.热空穴产生的三代电子在指向衬底的电场作用下向Si-SiO2界面移动,这解释了源区一侧栅氧化层损伤的产生原因.     

Simulating and modeling the breakdown voltage in a semi-insulating GaAs P+N junction diode

This work aims to determine the characteristic PN junction diode, subject to a reverse polarization, while I （breakdown voltage） of the inverse current in a GaAs specifying the parameters that influence the breakdown voltage of the diode. In this work, we simulated the behavior of the ionization phenomenon by impact breakdown by avalanche of the PN junctions, subject to an inverse polarization. We will take into account both the trapping model in a stationary regime in the P＋N structure using like material of basis the Ⅲ-Ⅴ compounds and mainly the GaAs semi-insulating in which the deep centers have in important densities. We are talking about the model of trapping in the space charge region （SCR） and that is the trap density donor and acceptor states. The carrier crossing the space charge region （SCR） of W thickness creates N electron-hole pairs： for every created pair, the electron and the hole are swept quickly by the electric field, each in an opposite direction, which comes back, according to an already accepted reasoning, to the crossing of the space charge region （SCR） by an electron or a hole. So the even N pair created by the initial particle provoke N2 ionizations and so forth. The study of the physical and electrical behaviour of semiconductors is based on the influence of the presence of deep centers on the characteristic I（V） current-tension, which requires the calculation of the electrostatic potential, the electric field, the integral of ionization, the density of the states traps, the diffusion current of minority in the regions （1） and （3）, the current thermal generation in the region （2）, the leakage current in the surface, and the breakdown voltage.     

基于ZigBee的水库水位监测及远程控制系统

国内水库水位测量大多采用人工测量的方法,或是通过GPRS实现远程监测。人工方法测量存在人身安全问题,测量数据的不准确性,监测的实时性较差等问题,利用GPRS对水库水位远程多点实时监控,功耗、供电等问题造成附加成本较高。系统采用STC89C52微控制器,处理传感器测得的水位数据,通过现场数码管实时显示水位信息,采用低功耗的ZigBee技术实现数据无线远程传输,监控中心通过C#编写的可视化界面实时观测水库水位信息。实验证明系统具有实时性强、数据准确、智能化高、易组网、成本低、便于安装和维护等优点,具有一定的应用价值。