与标准CMOS完全兼容的硅基LED器件模拟

采用工业标准 0 6 μmCMOS工艺设计了以反向击穿硅 p n结为基础的光发射器件 .讨论了该器件的光发射机理 .利用商业模拟软件对器件的工作特性进行了模拟 ,包括器件的正向和反向I V特性、p区掺杂浓度对击穿电压的影响以及门电压对器件发光强度的调制特性的影响等 .结果表明该器件是一种很有前途的硅发光器件 ,在光互连等领域具有广阔的应用前景.     

500 V体硅N-LDMOS器件研究

借助Tsuprem-4和Medici软件详细讨论分析了高压N-LDMOS器件的衬底浓度、漂移区注入剂量、金属场极板长度等参数与击穿电压之间的关系,通过对各参数的模拟设计,最终得到兼容体硅标准低压CMOS工艺的500V体硅N-LDMOS的最佳结构、工艺参数,通过I-V特性曲线可知该高压N-LDMOS器件的关态和开态击穿电压都达到500V以上,开启电压为1.5V,而且制备工艺简单,可以很好地应用于各种高压功率集成芯片。     

PDSOI nMOSFETs关态击穿特性

分别采用不同的背栅沟道注入剂量制成了部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件.对这些器件的关态击穿特性进行了研究.当背栅沟道注入剂量从1.0×1013增加到1.3×1013cm-2,浮体n型沟道器件关态击穿电压由5.2升高到6.7V,而H型栅体接触n型沟道器件关态击穿电压从11.9降低到9V.通过测量寄生双极晶体管静态增益和漏体pn结击穿电压,对部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件的击穿特性进行了定性解释和分析.     

PDSOI nMOSFETs关态击穿特性

分别采用不同的背栅沟道注入剂量制成了部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件.对这些器件的关态击穿特性进行了研究.当背栅沟道注入剂量从1.0×1013增加到1.3×1013cm-2,浮体n型沟道器件关态击穿电压由5.2升高到6.7V,而H型栅体接触n型沟道器件关态击穿电压从11.9降低到9V.通过测量寄生双极晶体管静态增益和漏体pn结击穿电压,对部分耗尽绝缘体上硅浮体和H型栅体接触n型沟道器件的击穿特性进行了定性解释和分析.     

硅PiN管的雪崩击穿的修正

硅PiN结构在工业产品中有多种应用,是多种二极管的基本结构。本文分析了该结构的雪崩击穿特性,推导得到一个适合于PiN结构的突变结雪崩击穿电压公式。该解析式能估算器件杂质分布为单边突变结、双边突变结和PiN结构的雪崩击穿电压,修正了以往解析式中i层宽度为零时,击穿电压为零的错误结论。该解析式对于PiN管的器件物理分析、工艺结构的优化和产品流水线的监控是有用的。     

一种新型硅基恒流二极管的特性研究

提出了一种新型硅基环状分布垂直沟道恒流二极管,包括并联的结型场效应晶体管和PIN整流管。建立了器件的数值模型,并利用SILVACO TCAD仿真工具对器件的恒定电流值、击穿电压等特征参数进行模拟。结果显示,该器件工作于正向时,恒流效果好,开启电压约为3 V,击穿电压可达140 V;该器件工作在反向时,表现出良好的整流特性,开启电压约为0.8 V。     

SOI横向二极管击穿特性分析

对硅片直接键合方法制作的 SOI横向二极管的击穿特性在不同条件下进行了测量 ,通过计算机模拟分析了击穿机理 ,从器件的几何尺寸和衬底偏置电压方面 ,提出了提高击穿电压的途径。     

100V体硅N-LDMOS器件研究

为了设计一款100 V体硅N-LDMOS器件,通过借助Tsuprem-4和Medici软件详细讨论分析了高压N-LDMOS器件衬底浓度、漂移区参数、金属场极板长度等与击穿电压、开态电阻之间的关系,最终得到兼容体硅标准低压CMOS工艺的100 V体硅N-LDMOS最佳结构、工艺参数.折衷考虑到了击穿电压、开态电阻这一对矛盾体以满足设计指标.通过模拟曲线可知该高压器件的关态和开态的击穿电压都达到要求,开启电压为1.5 V,而且完全兼容国内体硅标准低压CMOS工艺,可以很好地应用于各种高压功率集成芯片.     

应变SiGe沟道pMOSFET的击穿特性

以半导体器件二维数值模拟程序Medici为工具,模拟和对比了SiGepMOS同SipMOS的漏结击穿电压随栅极偏压、栅氧化层厚度和衬底浓度的变化关系;研究了SiGepMOS垂直层结构参数硅帽层厚度、SiGe层厚度及Ge剂量和p+ δ掺杂对于击穿特性的影响.发现SiGepMOS击穿主要由窄带隙的应变SiGe层决定,击穿电压明显低于SipMOS并随Ge组分增加而降低;SiGe/Si异质结对电场分布产生显著影响,同SipMOS相比电场和碰撞电离具有多峰值分布的特点;Si帽层及SiGe层参数对击穿特性有明显影响,增加p型δ掺杂后SiGepMOS呈现穿通击穿机制     

应变SiGe沟道pMOSFET的击穿特性

以半导体器件二维数值模拟程序Medici为工具,模拟和对比了SiGe pMOS同Si pMOS的漏结击穿电压随栅极偏压、栅氧化层厚度和衬底浓度的变化关系;研究了SiGe pMOS垂直层结构参数硅帽层厚度、SiGe层厚度及Ge剂量和p+ δ掺杂对于击穿特性的影响.发现SiGe pMOS击穿主要由窄带隙的应变SiGe层决定,击穿电压明显低于Si pMOS并随Ge组分增加而降低;SiGe/Si异质结对电场分布产生显著影响,同Si pMOS相比电场和碰撞电离具有多峰值分布的特点;Si帽层及SiGe层参数对击穿特性有明显影响,增加p型δ掺杂后SiGe pMOS呈现穿通击穿机制.     

基于CMOS工艺的Si-LED器件设计与测试

采用CSMC(华润上华)0.5 μm CMOS工艺设计和制备了正向偏置和反向偏置情况下发出两种不同种类光的Si-LED.在室温条件下,对器件进行了初步测试,正向导通电压为0.7 V,反向击穿电压为7.5V.器件的结构采用P-base层与n+区交叠,形成Si-pn结LED.观察了Si-LED发光显微照片及实际器件的版图,...     

基于标准CMOS工艺的Si基光发射器件

基于反偏雪崩击穿的发光原理,按照Chartered 0.35μm标准CMOS工艺要求,设计并制作了一种Si基光发射器件。在室温下对器件特性进行了初步测试,正向导通电压为0.75V,反向击穿电压为8.4V,能够在一个较宽的电压范围(8.4～12V)内稳定工作。总结了工艺对器件电学特性的影响,并将该器件结构与Snyman等人研究的器件结构进行了比较分析。该器件较强的边缘发光在平面结构的Si基片上集成光互联系统中将会有一定的应用价值。     

标准CMOS工艺栅控Si-LED设计与制备

采用新加坡半导体制备有限公司的0.35um EEPROM双栅标准CMOS工艺设计和制备了U型Si-LED发光器件。器件结构采用P+-N+-P+-P+-P+-N+-P+-P+-P+-N+-P+叉指结构形成U型器件,外部的两个P+区为保护环,在相邻的内部两个P+区之间使用多晶硅作为栅极来调控LED的正偏发光。使用奥林巴斯IC显示镜测得了硅LED实际器件的显微图形,并对器件进行了电学的正反向I-V特性测量。器件在室温下正向偏置,在100～140mA电流下对器件进行了光功率的检测,发光峰值在1089nm处。结果表明,器件发光功率随着栅控电压偏置电流的增加而增加。     

Graphene/SiO2/p‐GaN Diodes: An Advanced Economical Alternative for Electrically Tunable Light Emitters

Advanced materials that combine novel functionality and ease of applicability are central to the development of light‐emitting diodes (LEDs), which is of ever increasing commercial importance. Here a new metal‐insulator‐semiconductor (MIS) LED structure that combines economical fabrication with novel device properties is reported. The presented MIS‐LED consists of a graphene electrode on p‐GaN substrate separated by an insulating SiO₂ layer. It is found that the MIS‐LED possesses a unique tunability of the electroluminescence spectra depending on the bias conditions. Tunnel injection from graphene into the p‐GaN can explain the difference in luminescence spectra under forward and reverse bias. The demonstrated MIS‐LED expands the use of graphene and also possibly allows the direct integration of light emitters with other circuit elements.     

Reverse bias activation of salt-doped polymer light-emitting devices

We report sandwich polymer light-emitting devices doped with a lithium salt. The salt-doped polymer devices are initially conductive and weakly emitting under forward bias but blocking under reverse bias. The application of a large reverse bias or current activates the device, causing a dramatic increase in current and the onset of electroluminescence under reverse bias. Meanwhile, the forward-bias current and emission have become heavily suppressed. Moreover, the activated devices exhibit photovoltaic response whose polarity is opposite to that of an un-activated device. Electrical, electroluminescent, photoluminescent and photovoltaic properties of the activated devices suggest the formation of a p–n junction by in situ electrochemical doping. Devices made with a green-emitting polymer are quasi-frozen with no significant degradation in current density and light intensity after 1200 h of storage at room temperature.     

Silicon light emitting device in CMOS technology

A novel silicon light emitting device was realized with standard 0.35μm 2P4M Mixed Mode/RF CMOS technology. The device functions in a reverse breakdown mode and can be turned on at 8.3 V and operated normally at a wide voltage range of 8.3 V-12.0 V. An output optical power of 13.6 nW was measured at the bias of 10 V and 100 mA, and the emitted light intensity was calculated to be more than 1 mW/cm2. The optical spectrum of the device is in the range of 500-820 nm.     

Intrinsic electrochemical doping in blue light emitting polymer devices utilizing a water soluble anionic conjugated polymer

We report on light emitting device related properties of the water soluble blue light emitting anionic poly{1,4-phenylene-[9,9-bis(4-phenoxy-butylsulfonate)]fluorene-2,7-diyl} copolymer (PBS-PFP) with alkyl sulfonic acid sodium side chains. Compared to organic solvents water has the advantage of being environmentally friendly, which simplifies the handling during device fabrication by novel preparation techniques such as ink-jet printing. Light emitting devices fabricated from this polymer in thin film configuration show stable blue emission with an emission maximum at approximately 420 nm. Investigations concerning the current–density/voltage and the luminance/voltage device characteristics as well as the current–density over operation time at constant biases allow the identification of intrinsic electrochemical doping effects caused by ionic groups attached on the side chains of the polymer. Due to this fact, firstly the electroluminescence onset voltage for devices using high work-function electrodes for electron injection such as aluminum, which has the advantage of being air stable, can be distinctly reduced, and secondly devices fabricated from this polymer showed luminance in forward bias direction as well as in reverse bias direction.     

Two-dimensional simulation of silicon avalanche cathodes

The characteristics of silicon avalanche cathode as a novel electron emitting device with ultra-shallow p-n junctions have been studied using the two-dimensional device simulator PISCES-IIB. The steady-state simulation indicates that the nonplanar surface topology resulting from fabrication process causes current crowding near the edge of the emitting area where the surface step exists. Current crowding degrades the emission uniformity and also reduces the emission current under increased reverse bias. The nonplanar surface structure also causes punchthrough in the epitaxial layer as the reverse bias on the cathode increases. As a result, the percentage of the cathode current contributing to emission decreases, reducing the emission efficiency consequently. The simulation shows that the portion of the cathode current that flows through the emitting area drops to as much as 30% at cathode bias higher than 12 V, compared to the same current just after breakdown. This also affects the rate of increase in the total emission current which is the product of the emission efficiency and the overall cathode current     

有机发光器件中空穴注入对负电容的影响

对不同结构的有机发光器件(OLED)进行了电容-电压(C-V)特性测量,研究了不同空穴注入结构对OLED负电容的影响。结果表明,负电容的产生与OLED内部电场的分布有着密切的关系,负电容开始出现的频率与电压的平方根呈指数关系。与超薄的单层空穴注入层相比,掺杂的空穴注入层不仅能降低器件的驱动电压,而且其载流子传输特性和出现负电容时的初始电压对频率有着更强的依赖性。     

Optocoupler made from semiconducting polymers

Optocouplers (optoisolators) were fabricated using semiconducting polymers. The input unit is a polymer light emitting diode with an external quantum efficiency of ∼1% photons/electron. The output unit is a polymer photodiode with a quantum yield of ∼35% electrons/photon at 590 nm. Both units can be operated at bias voltages sufficiently low to be compatible with TTL and complementary metal-oxide semiconductor logic circuits. Since the transfer characteristic is nearly linear, the polymer optocoupler can be used in analogue circuits as well. The current transfer ratio reaches 2 × 10⁻³ under-10V reverse bias, comparable to that of commercial inorganic optocouplers.