芯片毛细管电泳电动进样的数值分析

利用集成毛细管电泳芯片进行生物化学分析时,电动进样是重要的操作步骤之一.本文通过建立数学模型,对“十“字型进样沟道内的电场分布进行了计算机数值模拟,通过改变进样电压和分析沟道内部电场分布,得到了进样及分离时的最佳电压组合.试验结果与模拟计算的结果吻合较好.     

芯片毛细管电泳电动进样的数值分析

利用集成毛细管电泳芯片进行生物化学分析时，电动进样是重要的操作步骤之一。本文通过建立数学模型，对“十”字型进样沟道内的电场分布进行了计算机数值模拟，通过改变进样电压和分析沟道内部电场分布，得到了进样及分离时的最佳电压组合。试验结果与模拟计算的结果吻合较好。     

负电子微分迁移率场效应管的二维数值分析

本文对于新型的负电子微分迁移率场效应管内部的电位、沿沟道方向的电场以及载流子浓度的稳态分布进行了二维数值模拟,结果表明通过适当选取器件尺寸、掺杂分布以及偏置电压,沿沟道方向可以产生一个处于负电子微分迁移率范围之内的均匀电场,使沟道具有负RC效应而不出现高场畴.     

一种具有N埋层的AlGaN/GaN高电子迁移率晶体管

为了进一步提高GaN HEMT器件的击穿电压,并保持低的导通电阻,文中提出了一种具有N型GaN埋层的AlGaN/GaN HEMT.该埋层通过调整器件的电场分布,降低了高场区的电场峰值,从而降低器件关断时的泄漏电流.该埋层使得栅漏之间的横向沟道电场分布更加均匀,提高了器件的击穿电压.通过Sentaurus TCAD仿真发...     

AlGaN/GaN HEMT击穿特性与受主陷阱相关性研究

通过计算沟道电场的分布,研究了受主陷阱对AlGaN/GaN HEMT器件击穿特性的影响.研究发现,有受主陷阱的条件下,漏端出现电场峰值,栅端电场峰值被大幅度削减.当Vg=0 V,Vd=60 V,受主陷阱浓度NA=1×10(17)cm-3时,栅端电场峰值与不加受主陷阱时相比可下降到56%.受陷阱电荷影响,当击穿电压大于某个电压时,漏端电场峰值超过栅端电场峰值,此时,击穿发生在漏端.该仿真结果修正了HEMT击穿总发生在栅端边缘处的传统看法.     

薄型双漂移区高压器件新结构的耐压分析

提出与CMOS工艺兼容的薄型双漂移区(TD)高压器件新结构.通过表面注入掺杂浓度较高的N-薄层,形成不同电阻率的双漂移区结构,改变漂移区电流线分布,降低导通电阻;沟道区下方采用P离子注入埋层来减小沟道区等位线曲率,在表面引入新的电场峰,改善横向表面电场分布,提高器件击穿电压.结果表明:TD LDMOS较常规结构击穿电压提高16%,导通电阻下降31%.     

高可靠性P-LDMOS研究

分析了沟道高电场分布产生原因及各个参数对高电场的影响,提出了两条沟道设计的原则--拉长沟道同时降低沟道浓度.模拟结果显示,两条原则能够有效地降低沟道两端的两个峰值电场,从而缓解沟道热载流子效应,提高P-LDMOS的可靠性.     

高可靠性P-LDMOS研究

分析了沟道高电场分布产生原因及各个参数对高电场的影响,提出了两条沟道设计的原则——拉长沟道同时降低沟道浓度.模拟结果显示,两条原则能够有效地降低沟道两端的两个峰值电场,从而缓解沟道热载流子效应,提高P-LDMOS的可靠性.     

基于能带调制模型的高压增强型AlGaN/GaN HFET器件

提出了一种能带调制模型,通过在异质结界面处引入负离子电荷(如氟离子)调制异质结处的局部能带分布,实现了对异质结界面处的高密度2DEG的改变。基于能带调制模型,提出了一种复合调制沟道AlGaN/GaNHFET器件。通过在增强型沟道调制区和RESURF调制区分别引入不同剂量的负离子,不仅实现了增强型器件,而且可以降低尖峰电场,优化异质结电场分布,提高器件击穿电压。通过器件仿真软件对其器件工作原理进行了模拟分析,并通过实验结果表明,其器件品质因子FOM由传统器件的4.8MW.cm-2提高到26.7MW.cm-2。     

部分耗尽SOI NMOSFET总剂量辐照的最坏偏置

通过模拟对ON、OFF、TG三种偏置下PD SOI NMOSFET的总剂量辐照效应进行了研究.模拟发现正沟道的最坏偏置是ON偏置,背沟道的最坏偏置与总剂量有关.当总剂量大时,背沟道的最坏偏置是OFF偏置;当总剂量小时则是TG偏置.而NMOSFET的最坏偏置则取决于起主要作用的是正栅还是背栅.由于辐照产生电子空穴对的过程与电场分布强相关,通过分析不同偏置下电场分布的差异确定最坏偏置的内在机制.     

功率LDMOS中的场极板设计

本文提出了LDMOS器件漂移区电场分布和电势分布的二维解析模型,并在此基础上得出了LDMOS漂移区电势分布和电场分布的解析表达式。通过表达式的结果,研究了多晶硅场板的长度和位置对于器件表面电场和电势的影响,解析结果与MEDICI结果相符。     

基于过渡金属氧化物薄膜为连接层的叠层有机电制发光器件的数值模型

By utilizing a two-step process to express the charge generation and separation mechanism of the transition metal oxides （TMOs） interconnector layer, a numerical model was proposed for tandem organic light emitting diodes （OLEDs） with a TMOs thin film as the interconnector layer. This model is valid not only for an n-type TMOs interconnector layer, but also for a p-type TMOs interconnector layer. Based on this model, the influences of different carrier injection barriers at the interface of the electrode/organic layer on the charge generation ability of interconnector layers were studied. In addition, the distribution characteristics of carrier concentration, electric field intensity and potential in the device under different carrier injection barriers were studied. The results show that when keeping one carrier injection barrier as a constant while increasing another carrier injection barrier, carri- ers injected into the device were gradually decreased, the carrier generation ability of the interconnector layer was gradually reduced, the electric field intensity at the interface of the organic/electrode was gradually enhanced, and the electric field distribution became nearly linear： the voltage drops in two light units gradually became the same. Meanwhile, the carrier injection ability decreased as another carrier injection barrier increased. The simulation re- sults agree with the experimental data. The obtained results can provide us with a deep understanding of the work mechanism of TMOs-based tandem OLEDs.     

Analytical model for the programming of source side injection SST superflash split-gate cell using two-dimensional analysis

An analytical model for source side injection programming of E²PROM is presented based on two-dimensional analysis on SST SuperFlash cells. Owing to SST cells dual-gate specific configuration and programming bias conditions, two maximum peaks are expected in the lateral electric field distribution along the channel. However, only hot electrons generated at the gap region, where the vertical field is in favor of electrons collection can effectively contribute to the gate current. A virtual gate with linearly increased potential is assumed in the gap region to solve the channel electric field distribution. By applying analytical electric field results to the Lucky-Electron model and impact-ionization model, SST cell gate current and substrate current models are derived and verified by experimental data.     

平板电容器边缘电场特性探究

平板电容器是＂电磁场与电磁波＂课程中静态场部分的重点分析对象。一般根据平板电容器的均匀电荷分布,求解平板电容器的电位和电场分布。本文考虑实际平板导体上电荷分布的不均匀性,利用逼近的方法,从分析导体的电荷密度出发,得出电荷分布的边缘效应,从而确定平板电容器边缘附近的电位和电场分布。仿真结果表明此逼近方法切实可行,具有一定...     

对接地网腐蚀后性能的仿真研究

为了分析接地网腐蚀后的性能,采用场路结合的算法,建立了一种接地网不等电位模型并进行仿真计算。利用节点电压方程和导体之间的互阻关系,形成ATP-EMTP仿真电路。通过对接地网导体腐蚀变细,电流注入点附近导体腐蚀断线和接地网边沿边角处导体腐蚀断线等情况下地表电位分布的仿真计算可以看出,接地网电流注入点附近及边沿边角处导体腐蚀断线会造成接地网内部巨大的电位差。研究表明,接地网应重点加强电流注入点附近及边缘边角处的抗腐蚀性能。     

复合介质层SOI高压器件电场分布解析模型

提出复合介质埋层SOI(compound dielectric buried layer SOI,CDL SOI)高压器件新结构,建立其电场和电势分布的二维解析模型,给出CDL SOI和均匀介质埋层SOI器件的RESURF条件统一判据.CDL SOI结构利用漏端低k(介电常数)介质增强埋层纵向电场,具有不同k值的复合介质埋层调制漂移区电场,二者均使耐压提高.借助解析模型和二维数值仿真对其电场和电势进行分析,二者吻合较好.结果表明,对低k值为2的CDL SOILDMOS,其埋层电场和器件耐压分别比常规SOI结构提高了82%和58%.     

The internal electric field distribution in bilayer organic light emitting diodes

The internal electric field distribution in a bilayer 4,4^′-bis[N-(1-napthyl)-N-phenylamino]-biphenyl/tris-(8-hydroxyquinoline) aluminium organic light emitting diode has been investigated experimentally using electroabsorption spectroscopy. The experimental results have been compared to those obtained from a drift–diffusion device simulation, further validating the model and highlighting the potential worth of such modelling. With the aid of the simulation, the electric field distribution can be explained in terms of charge carrier accumulation at the interface between the two organic layers, due to the HOMO and LUMO band offsets, and charge injection into the device, demonstrating the influence of contact materials on device behaviour.     

Potential distribution in voltage terminating structures with floating <Emphasis Type="Italic">p–n</Emphasis> junction rings of silicon radiation detectors

A model of the potential distribution in voltage terminating structures (VTSs) with floating p ⁺-n junction rings in silicon radiation detectors is proposed. The model is based on experimental current-voltage characteristic of interring gaps, measured for detectors based on high-resistivity silicon with resistivities from 1 to 25 kΩ cm. The physical basis of the model is the injection principle of current flow through VTS interring gaps, which becomes possible at a certain electric field distribution in space charge regions of p ⁺-n junctions of the sensitive contact and rings. It is shown that the injection current flow is a universal operation principle of the VTS with floating rings, which leads to rigid stabilization of potentials of individual rings. As a result, it becomes possible to divide the potential irrespective of the semiconductor material resistivity.     

行波电渗微流体驱动仿真和实验研究

为了探讨在封闭通道内微流体在行波电渗作用下的流动状态,进行了行波电渗微流体驱动实验及仿真研究。通过对行波电渗微流体驱动原理的分析,建立了行波电渗微流体驱动数学模型。根据微通道内电势分布满足Laplace方程及通道内流体流动满足Navier-Storks方程,并利用建立的边界条件,确定了行波电渗在微通道内电势及电场的分布,通过对电场及流场问题的耦合求解,获得了微通道内行波电渗微流体驱动流场。分析表明,其仿真计算结果与实验结果具有较好的一致性,从而验证了行波电渗微流体驱动理论模型的正确性,为进一步研究和分析行波电渗微泵提供了理论工具和仿真手段。     

反向开关复合管的物理模型与数值方法实现

从大注入半导体物理的基本理论推导得到了反向开关复合管(RSD)工作的基本物理方程.通过考虑大注入和强电场效应,建立了RSD以pnn 二极管方式工作于反向预充阶段,以pin二极管方式工作于正向导通阶段的物理模型.采用有限差分法把器件工作的偏微分方程转化为差分方程,并将相应的边界条件转化为精度较高的离散化形式.结合RSD工作的典型电路建立电路方程组,采用Runge-Kutta方法求解,由非平衡载流子分布得到了RSD的电压、电流波形.通过RSD的放电实验与模型计算进行比较,分析了误差产生的原因,论证了物理模型本身及数值方法的合理性.通过应用电路说明了模型及算法的实用价值.物理模型和数值方法对于RSD器件设计及仿真电路的开发具有指导意义.