含有本征SiGe层的SiGe异质结双极晶体管集电结耗尽层宽度模型

本文分别建立了含有本征SiGe层的SiGe HBT(异质结双极晶体管)集电结耗尽层各区域的电势、电场分布模型,并在此基础上,建立了集电结耗尽层宽度和延迟时间模型,对该模型进行了模拟仿真,定量地分析了SiGe HBT物理、电学参数对集电结耗尽层宽度和延迟时间的影响,随着基区掺杂浓度和集电结反偏电压的提高,集电结耗尽层延迟时间也随之增大,而随着集电区掺杂浓度的提高和基区Ge组分增加,集电结耗尽层延迟时间随之减小. 关键词： SiGe HBT 集电结耗尽层 延迟时间     

漏致势垒降低效应对短沟道应变硅金属氧化物半导体场效应管阈值电压的影响

结合应变硅金属氧化物半导体场效应管(MOSFET)结构,通过求解二维泊松方程,得到了应变Si沟道的电势分布,并据此建立了短沟道应变硅NMOSFET的阈值电压模型.依据计算结果,详细分析了弛豫Si_1－βGe_β中锗组分β、沟道长度、漏电压、衬底掺杂浓度以及沟道掺杂浓度对阈值电压的影响,从而得到漏致势垒降低效应对小尺寸应变硅器件阈值电压的影响,对应变硅器件以及电路的设计具有重要的参考价值. 关键词： 应变硅金属氧化物半导体场效应管 漏致势垒降低 二维泊松方程 阈值电压模型     

A device model for thin silicon-on-insulator SiGe heterojunction bipolar transistors with saturation effects

In this paper, we describe the saturation effect of a silicon germanium (SiGe) heterojunction bipolar transistor (HBT) fabricated on a thin silicon-on-insulator (SOI) with a step-by-step derivation of the model formulation. The collector injection width, the internal base—collector bias, and the hole density at the base—collector junction interface are analysed by considering the unique features of the internal and the external parts of the collector, as they are different from those of a bulk counterpart.     

小尺寸应变Si nMOSFET物理模型的研究

本文运用高斯定律得出多晶SiGe栅应变Si nMOSFET的准二维阈值电压模型,并从电流密度方程出发建立了小尺寸应变Si nMOS器件的I-V特性模型.对所得模型进行计算分析,得出沟道Ge组分、多晶Si_1-yGe_y栅Ge组分、栅氧化层厚度、应变Si层厚度、栅长以及掺杂浓度对阈值电压的影响.运用二维器件模拟器对器件表面势和I-V特性进行了仿真,所得结果与模型仿真结果一致,从而证明了模型的正确性. 关键词： 多晶SiGe栅 高斯定理 阈值电压 速度过冲     

An analytical threshold voltage model for dual-strained channel PMOSFET

Based on the analysis of vertical electric potential distribution across the dual-channel strained p-type Si/strained Si 1-x Ge x /relaxd Si 1-y Ge y (s-Si/s-SiGe/Si 1-y Ge y) metal-oxide-semiconductor field-effect transistor (PMOSFET),an-alytical expressions of the threshold voltages for buried channel and surface channel are presented.And the maximum allowed thickness of s-Si is given,which can ensure that the strong inversion appears earlier in the buried channel (compressive strained SiGe) than in the surface channel (tensile strained Si),because the hole mobility in the buried channel is higher than that in the surface channel.Thus they offer a good accuracy as compared with the results of device simulator ISE.With this model,the variations of threshold voltage and maximum allowed thickness of s-Si with design parameters can be predicted,such as Ge fraction,layer thickness,and doping concentration.This model can serve as a useful tool for p-channel s-Si/s-SiGe/Si 1-y Ge y metal-oxide-semiconductor field-effect transistor (MOSFET) designs.     

Valence band structure and density of states effective mass model of biaxial tensile strained silicon based on k·p theory

After constructing a stress and strain model, the valence bands of in-plane biaxial tensile strained Si is calculated by k·p method. In the paper we calculate the accurate anisotropy valance bands and the splitting energy between light and heavy hole bands. The results show that the valance bands are highly distorted, and the anisotropy is more obvious. To obtain the density of states (DOS) effective mass, which is a very important parameter for device modeling, a DOS effective mass model of biaxial tensile strained Si is constructed based on the valance band calculation. This model can be directly used in the device model of metal-oxide semiconductor field effect transistor (MOSFET). It also a provides valuable reference for biaxial tensile strained silicon MOSFET design.     

新型高速半导体器件IMOS阈值电压解析模型

本文在研究IMOS器件结构的基础上, 分析了该器件不同区域的表面电场, 结合雪崩击穿条件, 建立了P-IMOS的阈值电压解析模型. 应用MATLAB对该器件阈值电压模型与源漏电压、栅长和硅层厚度的关系进行了数值分析, 并用二维器件仿真工具ISE进行了验证. 结果表明, 源电压越大, 阈值电压值越小; 栅长所占比例越大, 阈值电压值越小, 硅层厚度越小, 阈值电压值越小. 本文提出的模型与ISE仿真结果一致, 也与文献报道符合. 这种新型高速半导体器件IMOS阈值电压解析模型的建立为该高性能器件及对应电路的设计、仿真和制造提供了重要的参考.     

应变Si全耗尽SOI MOSFET二维亚阈电流模型

本文通过求解二维泊松方程,为应变Si 全耗SOI MOSFET建立了全耗尽条件下表面势模型,利用传统的漂移-扩散理论.在表面势模型的基础上,得到了应变Si 全耗SOI MOSFET的亚阈电流模型,并通过与二维器件数值模拟工具ISE的结果做比较,证明了所建立的模型的正确性.根据所建立的模型,分析了亚阈电流跟应变Si应变度的大小,应变Si膜的厚度和掺杂浓度的关系,为应变Si 全耗SOI MOSFET物理参数设计提供了重要参考. 关键词： 应变硅 FD-SOI MOSFET 表面势 亚阈电流