A Numerical Method for Calculating Transmission Coefficients Across Arbitrary Potential Barriers with High Accuracy

We report a new method for calculating transmission coefficients across arbitrary potential barriers based on the Runge-Kutta method. A numerical solution of the Schrodinger equation is calculated using the Runge-Kutta method,and a new model is established to analyze the numerical results to find the transmission coefficient. This technique is applied to various cases, such as parabolic potential barrier and double-barrier structures. Transmission probability with high precision is obtained and discussed. The tunnelling current density through a MOS structure is also explored and the result coincides with the Fowler-Nordheim model,which indicates the applicability of our method.

SOI光波导高速电光调制器的研究进展

介绍了不同截面大小的SOI(silicon-on-insulator)波导单模条件,详细描述了几种降低传输损耗,消除偏振相关,提高耦合效率的技术手段.分析比较了一种带有MOS(metal-oxide-semiconductor)电容结构和一种具有微环结构的高速电光调制器,其调制频率分别达到10和1.5GHz.

Sensitivity of Total-Dose Radiation Hardness of SIMOX Buried Oxides to Doses of Nitrogen Implantation into Buried Oxides

In order to improve the total-dose radiation hardness of the buried oxides(BOX) in the structure of separa tion-by-implanted-oxygen(SIMOX) silicon-on-insulator(SOI), nitrogen ions are implanted into the buried oxides with two different doses,2 × 1015 and 3 × 1015 cm-2 , respectively. The experimental results show that the radiation hardness of the buried oxides is very sensitive to the doses of nitrogen implantation for a lower dose of irradiation with a Co-60 source. Despite the small difference between the doses of nitrogen implantation, the nitrogen-implanted 2 × 1015 cm-2 BOX has a much higher hardness than the control sample (i. e. the buried oxide without receiving nitrogen implantation) for a total-dose irradiation of 5 × 104rad(Si), whereas the nitrogen-implanted 3 × 1015 cm-2 BOX has a lower hardness than the control sample. However,this sensitivity of radiation hardness to the doses of nitrogen implantation reduces with the increasing total-dose of irradiation (from 5 × 104 to 5 × 105 rad (Si)). The radiation hardness of BOX is characterized by MOS high-frequency (HF) capacitance-voltage (C-V) technique after the top silicon layers are removed. In addition, the abnormal HF C-V curve of the metal-silicon-BOX-silicon(MSOS) structure is observed and explained.

部分耗尽型SOI CMOS模拟电路设计研究

介绍了部分耗尽型SOI MOS器件浮体状态下的Kink效应及对模拟电路的影响.阐述了4种常用体接触方式及其他消除部分耗尽型SOI MOS器件Kink效应的工艺方法,同时给出了部分耗尽型SOIMOSFET工作在浮体状态下时模拟电路的设计方法.

注氮工艺对SIMOX器件电特性的影响

研究了氮离子注入对SIMOX器件电特性的影响.氮注入SIMOX的埋氧层并退火后,将减小前栅MOS-FET/SIMOX的阈电压,提高其漏源击穿电压但对栅击穿电压影响较小.氮注入方式对SIMOX器件的I-V特性有重要影响.

突破间接带局限创新Si基激光器

Si基高效发光与受激光发射是Si基光子学突破性发展的关键课题,它的实现对Si基微电子学的发展有深远的重大意义.由于受到天然Si材料间接带能带结构的限制,Si材料的发光效率极低,更谈不上可实现受激光发射,人工改性就成为当代研究、开拓的主要途径.新的Si基直接带体材料(如β-FeSi2等)的探索,Ge/Si量子阱、超晶格、量子点的能带工程介观改性,子带发光跃迁的探索,异类元素插入短周期超晶格中的化学键改性,以及SiO2高浓度nc-Si的生成和高激活度稀土离子的掺入发光等已开展了多途径的研究,不同程度上取得了重要的进展,一种MIS结构电子隧道注入高效发光器件已在SiO2:RE MOS结构中实现.运用激光器件物理的深入设计和新的器件技术的引入,可以预计本世纪初叶,对实现Si基激光器的奢望将会成为现实,无疑它对Si基光子学、Si基集成光电子学乃至信息高科技的发展将作出历史性的巨大贡献.

新型硅基双异质外延SOI材料Si/γ-Al_2O_3/Si制备

异质外延法是目前制备新型SOI材料的技术途径之一。采用低压化学气相沉积技术(LPCVD)在硅衬底上先外延r-A1-2O-3绝缘单晶薄膜，制备出硅衬底上外延氧化物外延结构r-Al-2O-3／Si(EOS)，然后采用类似SOS薄膜生长的常压CVD(APCVD)方法在EOS上外延硅单晶薄膜，形成新型硅基双异质SOl材料Si／r-Al-2O-3／Si。利用反射高能电子衍射(RHEED)、X射线衍射(XRD)、俄歇电子能谱(AES)及MOS电学测量等技术表征分析了Si(100)／r-Al-2O-3(100)／Si(100)SOI异质结构的晶体结构、组分和电学性能。测试结果表明，已成功实现了高质量的新型双异质外延SOI结构材料Si(100)／ r-Al-2O-3(100)／Si(100)，r-Al-2O-3与Si外延薄膜均为单晶，r-Al-2O-3薄膜具有良好绝缘性能，SOI结构界面清晰陡峭，该SOI材料可应用于CMOS电路的研制。

热退火γ-Al_2O_3/Si异质结构薄膜质量改进

采用高真空MOCVD外延技术，利用TMA（Al(CH_3)_3）和O_2作为反应源，在Si(100)衬底上外延生长γ－Al_2O_3绝缘膜形成γ-Al_2O_3/Si异质结构材料。同时，引入外延后退火工艺以便改善γ-Al_2O_3薄膜的晶体质量及电学性能。测试结果表明，通过在O_2常压下的退火工艺可以有效地消除γ－Al_2O_3外延层的残余热应力及孪晶缺陷，改善外延层的晶体质量，同时可以提高MOS电容的抗击穿能力，降低漏电电流。

与CMOS工艺兼容的硅高速光电探测器模拟与设计

用器件模拟的方法，设计了一种与常规CMOS工艺兼容的硅高速光电探测器，该探测器可与CMOS接收机电路单片集成，对该探测器进行了器件模拟研究，给出了该探测器的电路模型。通过MOSIS（MOS implementation support project）0.35 μm COMS工艺制做了该探测器，实际测试了该器件的频率响应和波长响应，探测器频率响应在1GH以上，峰值波长响应在0.69 μm。

Heteroepitaxial growth of novel SOI material Si/gamma-Al2O3/Si

In this paper, we report the fabrication of Si-based double hetero-epitaxial SOI materials Si/gamma-Al2O3/Si. First, single crystalline gamma-Al2O3 (100) insulator films were grown epitaxially on Si(100) by LPCVD, and then, Si(100) epitaxial films were grown on gamma-Al2O3 (100)/Si(100) epi-substrates using a CVD method similar to silicon on sapphire (SOS) epitaxial growth. The Si/gamma-Al2O3 (100)/Si(100) SOI materials are characterized in detail by RHEED, XRD and AES techniques. The results demonstrate that the device-quality novel SOI materials Si/gamma-Al2O3 (100)/Si(100) has been fabricated successfully and can be used for application of MOS device.

Studies of 6H-SiC devices

Silicon carbide (SiC) is recently receiving increased attention due to its unique electrical and thermal properties. It has been regarded as the most appropriate semiconductor material for high power, high frequency, high temperature, and radiation hard microelectronic devices. The fabrication processes and characterization of basic device on 6H-SiC were systematically studied. The main works are summarized as follows:The homoepitaxial growth on the commercially available single-crystal 6H-SiC wafers was performed in a modified gas source molecular beam epitaxy system. The mesa structured p(+)n junction diodes on the material were fabricated and characterized. The diodes showed a high breakdown voltage of 800 V at room temperature. They operated with good rectification characteristics from room temperature to 673 K.Using thermal evaporation, Ti/6H-SiC Schottky barrier diodes were fabricated. They showed good rectification characteristics from room temperature to 473 K. Using neon implantation to form the edge termination, the breakdown voltage was improved to be 800 V.n-Type 6H-SiC MOS capacitors were fabricated and characterized. Under the same growing conditions, the quality of polysilicon gate capacitors was better than Al. In addition, SiC MOS capacitors had good tolerance to gamma rays. (C) 2002 Published by Elsevier Science B.V.

一种红外探测器专用77K工作CMOS前置放大器

利用single endedfolded cascode结构和MOS管工作在线性区做反馈电阻,实现了一种在77K工作的高性能低功耗、低噪声前置放大器.分析了它的噪声特性,提出了减少噪声的措施.此前置放大器用1.2μm的标准CMOS工艺制造完成.经过测试,这种前置放大器在低温77K下能正常工作,反馈电阻大小为兆欧级,线性度达到了1%,等效输入噪声电流仅0.03pA/Hz,功耗小于1mW.

基于DMOS管的电荷灵敏前置放大器设计；Design of A Charge Sensitive Preamplifier Based on DMOS FET

提出了一种由DMOS场效应管构成的电荷灵敏前置放大器,可用于硅,Si(Li),CdZnTe及CsI探测器。该前置放大器采用不同于传统的阻容反馈式的电路结构,完全使用MOS管搭建,该前放的设计完成为设计实现ASIC电路准备了技术基础。由Multisi m仿真结果看出该电荷灵敏前置放大器输出信号上升时间小于15ns,并且具有很好的稳定性。

基于CMOS器件的专用放大电路设计

随着国家大科学工程兰州重离子加速器冷却储存环(HIRFL-CSR)建成，CSRm实验探测系统也正在建设当中。CSRm实验探测系统具有多种探测器数万个探测单元。对于这样先进的探测器和大型实验探测系统采用传统的电子学仪器和方法已经无法构成读出电子学系统和数据获取系统，对前端读出电子学系统、数据获取系统提出更高的要求。因此，采用专用集成电路芯片(ASIC)构成前端读出电子学系统是最可行的方法。本论文所述的基于MOS管的专用放大电路设计正是基于集成电路（ASIC）芯片构建前端读出电子学系统的前期研究子部分。作为ASIC前端读出电子学研究的一部分，本论文主要阐述基于MOS器件的放大电路的研究，主要包括以下内容： 1、设计及实现基于CMOS管的电荷灵敏前置放大器，最后给出制作PCB板后的实验室调试结果； 2、设计仿真基于DMOS管的电荷灵敏前置放大器，对仿真结果进行讨论； 3、利用集成电路设计软件Tanner Pro实现电荷灵敏前置放大器的物理版图设计

微功耗核谱数据获取系统

本文介绍我们最新研制的微功耗核谱数据获取系统。目前，该系统基于微型计算机（IBM PC 486）获取，有待进一步发展成单片机获取系统。该系统具有功能强、功耗低、体积小、重量轻以及抗辐射的特点。为了降低功耗，电路设计中尽量使电路简单化，并选用微功耗、抗辐射的MOS场效应管元件。功率消耗单通道小于2.2w，若做成四通道可少于4W。 本系统以脉冲幅度分析方式获取数据，软件采用Turbo C 2.0编写，界面友好，操作方便。