基于单π模型的RF螺旋电感模型及参数提取法

提出了一种基于单π模型的RF螺旋电感等效电路模型及参数提取方法。该模型在传统单π模型基础上,增加支路间的并联RC网络来表征衬底耦合。在串联支路,增加RL网络来模拟趋肤效应和邻近效应。采用分频段的方法来合理简化等效电路。采用直接解析法来获得等效电路网络中所有的模型参数,无需任何优化。验证结果表明,在0~40 GHz范围内,模型值与仿真值吻合较好。该模型及参数提取方法不仅能简化计算量,还能更好地解释电路行为,对RFIC设计有参考价值。     

22 nm FDSOI器件的制备与背偏效应研究

提出了一种基于后栅极工艺的22 nm 全耗尽绝缘体上硅(FDSOI)器件的制备方法。基于电学测试结果,分析了器件的基本性能,研究了背栅偏压对器件性能的影响。结果表明,器件的开关电流比比较高、亚阈值摆幅较小,符合产业的一般标准。背栅偏压对长沟道和短沟道器件的阈值电压均有明显的影响。电路设计人员可以根据不同需求,选择工作在正向体偏置(FBB)模式或者反向体偏置(RBB)模式的器件。     

基于神经网络的逻辑门NBTI退化建模与计算

提出了基于神经网络的逻辑门退化延迟模型。根据逻辑门延迟数据特征,采用神经网络BP算法,对仿真样本数据进行训练,获得7种基本逻辑门延迟退化计算方法以及网络模型参数。基于45 nm CMOS工艺进行验证,模型计算值与Spice仿真数据的误差不超过5%。在此基础上,提出NBTI效应下的电路路径延迟退化计算流程,并编写计算程序,对基本逻辑门构成的任意组合逻辑电路(ISCAS85)进行NBTI退化分析,获得路径时序的NBTI退化量。采用该模型,可在电路设计阶段预测电路时序,为高性能、高可靠性数字集成电路的设计提供重要依据。     

14 nm FinFET栅围寄生电容的建模与拟合

提出了一种基于保角映射方法的14 nm鳍式场效应晶体管(FinFET)器件栅围寄生电容建模的方法。对FinFET器件按三维几何结构划分寄生电容的种类,再借助坐标变换推导出等效电容计算模型,准确表征了不同鳍宽、鳍高、栅高和层间介质材料等因素对寄生电容的依赖关系。为了验证该寄生电容模型的准确性,对不同结构参数的寄生电容进行三维TCAD仿真。结果表明,模型计算结果与仿真结果的拟合度好,准确地反映了器件结构与寄生电容之间的依赖关系。     

Comparison of total dose effects on SiGe heterojunction bipolar transistors induced by different swift heavy ion irradiation

The degradations in NPN silicon-germanium （SiGe） heterojunction bipolar transistors （HBTs） were fully studied in this work, by means of 25-MeV Si, 10-MeV C1, 20-MeV Br, and 10-MeV Br ion irradiation, respectively. Electrical parameters such as the base current （IB）, current gain （β）, neutral base recombination （NBR）, and Early voltage （VA） were investigated and used to evaluate the tolerance to heavy ion irradiation. Experimental results demonstrate that device degradations are indeed radiation-source-dependent, and the larger the ion nuclear energy loss is, the more the displacement damages are, and thereby the more serious the performance degradation is. The maximum degradation was observed in the transistors irradiated by 10-MeV Br. For 20-MeV and 10-MeV Br ion irradiation, an unexpected degradation in Ic was observed and Early voltage decreased with increasing ion fluence, and NBR appeared to slow down at high ion fluence. The degradations in SiGe HBTs were mainly attributed to the displacement damages created by heavy ion irradiation in the transistors. The underlying physical mechanisms are analyzed and investigated in detail.     

单界面陷阱对7 nm P型GAAFET性能影响研究

采用3D TCAD软件仿真分析了单界面陷阱对7 nm P型全环栅场效应晶体管DC和AC性能的影响。研究结果表明:单个陷阱能使转移特性曲线发生严重偏移;当单界面陷阱位于沟道中心附近且陷阱能级靠近导带时,对关态电流和阈值电压的影响最大;陷阱使栅电容的相对变化量小于1%;环栅晶体管沟道长度和纳米线直径的缩小会加重陷阱对器件性能的影响,高介电常数材料的Spacer可减小陷阱引起的沟道能带弯曲程度,从而缓解陷阱对器件性能的影响。在调节器件结构参数使器件性能最大化的同时,应使陷阱对器件性能的影响最小化。     

不同剂量率下锗硅异质结双极晶体管电离损伤效应研究

对于相同制作工艺的NPN锗硅异质结双极晶体管(SiGe HBT), 在不同辐照剂量率下进行⁶⁰Co γ射线的辐照效应与退火特性的研究. 测量结果表明, 两种辐照剂量率下, 随着辐照总剂量增加, 晶体管基极电流增大, 共发射极电流放大倍数降低, 且器件的辐照损伤、性能退化与辐照剂量率相关, 低剂量率下辐照损伤较高剂量率严重. 在经过与低剂量率辐照等时的退火后, 高剂量率下的辐照损伤仍较低剂量率下的损伤低, 即待测SiGeHBT具有明显的低剂量率损伤增强效应(ELDRS). 本文对相关的物理机理进行了探讨分析. 关键词： 锗硅异质结双极晶体管 低剂量率辐照损伤增强 辐照效应     

功率半导体器件辐射效应综述

功率半导体器件是航天器电源系统中的核心元件,太空环境中的粒子辐射会使其发生失效。首先,总结了硅功率半导体器件几种主要的辐射效应。然后,介绍了近年来一些新的研究成果和研究热点。最后,对第三代半导体功率器件中的辐射效应进行了简单介绍。     

A single-event transient induced by a pulsed laser in a silicon-germanium heterojunction bipolar transistor

A study on the single event transient (SET) induced by a pulsed laser in a silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) is presented in this work. The impacts of laser energy and collector load resistance on the SET are investigated in detail. The waveform, amplitude, and width of the SET pulse as well as collected charge are used to characterize the SET response. The experimental results are discussed in detail and it is demonstrated that the laser energy and load resistance significantly affect the SET in the SiGe HBT. Furthermore, the underlying physical mechanisms are analyzed and investigated, and a near-ideal exponential model is proposed for the first time to describe the discharge of laser-induced electrons via collector resistance to collector supply when both base-collector and collector-substrate junctions are reverse biased or weakly forward biased. Besides, it is found that an additional multi-path discharge would play an important role in the SET once the base-collector and collector-substrate junctions get strongly forward biased due to a strong transient step charge by the laser pulse.     

Improved high-frequency equivalent circuit model based on distributed effects for SiGe HBTs with CBE layout

In this paper, we present an improved high-frequency equivalent circuit for SiGe heterojunction bipolar transistors(HBTs) with a CBE layout, where we consider the distributed effects along the base region. The actual device structure is divided into three parts: a link base region under a spacer oxide, an intrinsic transistor region under the emitter window,and an extrinsic base region. Each region is considered as a two-port network, and is composed of a distributed resistance and capacitance. We solve the admittance parameters by solving the transmission-line equation. Then, we obtain the smallsignal equivalent circuit depending on the reasonable approximations. Unlike previous compact models, in our proposed model, we introduce an additional internal base node, and the intrinsic base resistance is shifted into this internal base node,which can theoretically explain the anomalous change in the intrinsic bias-dependent collector resistance in the conventional compact model.