Si/SiGe异质结双极晶体管的研制

通过理论分析计算，计算机模拟和工艺实验，对Si/SiGe异质结双极晶体管（HBT）的结构参数进行了精细的优化设计，特别是采用了本征间隔层和新颖的Ge分布曲线，有效地削弱了基区杂质外扩散，基区复合和异质结势垒效应的不利影响。开发了兼容于硅工艺的锗硅HBT工艺，并据此试制出了Si/SiGeHBT，测量结果表明，器件的直流和交流特性均较好，电流放大系数为50，截止频率fT为5.1GHz。     

SiGe/Si光电探测器研究进展

本文综述了目前国内外在工作波长１．３～１．５μｍ的ＳｉＧｅ／Ｓｉ超晶格探测器和工作波长为８～１２μｍ的ＳｉＧｅ／Ｓｉ异质结长波长红外探测器方面的研究进展，并分析了存在的问题和材料的各种生长方法。     

具有高电流处理能力的多发射极条微波功率GeSi HBT

本文对多发射极条(指)微波功率GeSi HBT进行了设计、制造和测试,并就测试结果对电流处理能力进行了研究.实验结果表明,对20～80指的GeSi HBT,发射极单位长度的电流密度I0在1.67～1.06A/cm之间变化.随发射极条数的增加,I0逐渐减少,分析认为这是由发射极条之间的热耦合引起有源区的温度非均匀分布而导致的.并且通过测试所得到的I0值,证明多指GeSi HBT可通过选择合适的发射极条数、条长和发射区面积获得更高的电流处理能力.     

SiGe／Si光电探测器研究进展

本文综述了目前国内外在工作波长１．３－１．５μｍ的ＳｉＧｅ／Ｓｉ超晶格探测器的工作波长为８－１２μｍ的ＳｉＧｅ／Ｓｉ异质结长波长红外探测器方面的研究进展，并分析了存在的问题和材料的各种生长方法。     

SiGe/Si异质结光电器件

SiGe/Si异质结光电器件及其光电集成(OEIC)是硅基光电研究的一个非常引人注目的领域.综述了SiGe/Si异质结材料的基本性质,SiGe/Si异质结光电器件的结构、性能、应用及其光电集成.重点介绍了SiGe/Si光电探测器及其与其他相关器件的集成.     

超宽带SiGe HBT低噪声放大器的设计和分析

设计了一款具有电阻反馈的新型超宽带(UWB)SiGe HBT低噪声放大器(LNA).因为摒弃了使用占片面积大的电感,所以极大节省了放大器的芯片面积和制作成本.在新型放大器的反馈支路中,使用了复合分布式电阻和隔直流电容,代替了传统的单一电阻.用这种方式设计的LNA,仅通过调整与电容串联的电阻就可以极大地改善放大器的端口匹...     

WC和Si衬底生长金刚石薄膜的研究

采用ＳＥＭ,Ｒａｍａｎ光谱等手段,较全面系统地研究了ＨＦＣＶＤ法在ＷＣ和Ｓｉ衬底上生长金刚石薄膜时,衬底预处理、碳源深度、热丝及衬底温度等对金刚石形核、生长的影响。并对两种衬底进行了对比与分析,最后总结出影响金刚石形核密度、形核速率、晶形结构及晶形完善性的关键因素。     

Si(001)衬底上方形3 C-SiC岛的LPCVD生长

Si衬底上SiC的异质外延生长深受关注,为了了解Si衬底上的成核及长大过程,采用PLCVD方法在Si(001)衬底上生长出了方形3C-SiC岛,利用Nomarski光学显微镜和扫描电子显微镜（SEM）观察了SiC岛的形状,尺寸,密度和界面形貌,结果表明,3C－SiC岛生长所需的Si原子来自反应气源,衬底上的Si原子不发生迁移或外扩散,气相中C原子浓度决定了SiC岛的生长过程。     

基于高阻硅衬底的微波传输线和数字移相器

在高阻硅衬底上微波传输线以及工作在7.5～8.5GHz频带的四位数字移相器.测试表明,在高阻硅衬底上制备的50Ω微带线在5～15GHz频率范围内的插入损耗低于0.8dB/cm;在同样衬底上用混合集成技术制作的7.5～8.5GHz四位数字移相器的各状态插入损耗为(7.5±3)dB,回波损耗大于12dB,均方根(RMS)相位误差小于5°.具有良好的微波器件性能.     

C~+离子注入SiGe衬底提高NiSiGe表面和界面特性研究

本文主要研究了不同剂量C+离子预先注入Si0.8Ge0.2衬底后,对Ni和Si0.8Ge0.2反应的影响。研究结果充分表明:C+离子注入的Si0.8Ge0.2衬底,降低了Ni和Si0.8Ge0.2反应的速度,提高了NiSi0.8Ge0.2的热稳定性。此外,我们发现C原子分布在NiSi0.8Ge0.2/Si0.8Ge0.2的界面,大幅度降低了NiSi0.8Ge0.2表面和NiSi0.8Ge0.2/Si0.8Ge0.2界面的粗糙度,高剂量C+注入的样品效果更为明显。     

Electrical Performance of Electron Irradiated SiGe HBT and Si BJT

The change of electrical performances of 1 MeV electron irradiated silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied. After electron irradiation, both the collector current IC and the base current IB changed a little, and the current gain β decreased a little for SiGe HBT. The higher the electron irradiation fluence was, the lower the IC decreased. For conventional Si BJT, IC and IB increased as well as /? decreased much larger than SiGe HBT under the same fluence. The contribution of IB was more important to the degradation of β for both SiGe HBT and Si BJT. It was shown that SiGe HBT had a larger anti-radiation threshold and better anti-radiation performance than Si BJT. The mechanism of electrical performance changes induced by irradiation was preliminarily discussed.     

横向尺寸的变化对SiGe HBT高频噪声的影响

从发射极条宽、发射极条长、基极条数、发射极与基极间距四个方面分析了横向尺寸变化对SiGe HBT高频噪声的影响.结果表明增加发射极条长、基极条数和减小发射极与基极间距可以较为有效地减小晶体管噪声,而减小发射极与基极间距对噪声的改善效果比较显著.发射极与基极间距从1μm减小到0.5μm,2GHz工作频率下最小噪声系数可减小9dB,在0.5GHz工作频率下最小噪声系数可降至1.5dB,2GHz工作频率下最小噪声系数为3dB.     

改善多指功率SiGe HBTs热稳定性的版图设计

提出非均匀指间距结构功率SiGe HBTs的版图设计用以改善热稳定性。模拟和实验结果均表明,与传统的均匀指间距结构相比,非均匀指间距结构HBT的峰值结温和温度分布非均匀性均得到显著改善。上述改善归功于非均匀指间距结构HBT中心指间距的增加,从而有效阻止热流由外侧指流向中心指处。此外,与均匀指间距结构器件相比,其热阻改善13.71%,热退化功率水平提高22.8%。因此,模拟和实验均证明采用非均匀指间距结构HBT的版图设计可有效改善功率HBTs热稳定性。     

SiGe／Si和SGOI材料的Li离子束RBS分析

SiGe合金薄膜中的Ge含量度分布对材料的禁带宽度和制作器件的性能有十分重要的影响。本文用Li离子束卢瑟福背散射分析法对SiGe／Si和SiGe-OI材料样品进行了分析。与TEM，SEM、Raman等分析结果进行比较表明，Li离子束RBS分析可同时测量SiGe层厚度，Ge含量度其深度分布，Si过渡层和SiO2层厚度，并有较好的测量精度。     

SiGe/Si hetero-field-effect-transistor with PN-junction gate

We report the first SiGe/Si HFET with a PN junction as a gate electrode. The epitaxial layer structure of the device is grown by MBE on a relaxed SiGe buffer. A mesa technology is used for device fabrication with implanted contact areas for source and drain and lift off technique for metallization. First DC results show the promising performance of this novel structure with respect to gate leakage current and breakdown voltage.     

High performance infra-red detectors based on Si/SiGe multilayers quantum structure

Recently, single crystalline (Sc) Si/SiGe multi quantum structure has been recognized as a new low-cost thermistor material for IR detection. Higher signal-to-noise (SNR) ratio and temperature coefficient of resistance (TCR) than existing thermistor materials have converted it to a candidate for infrared (IR) detection in night vision applications. In this study, the effects of Ge content, C doping and the Ni silicidation of the contacts on the performance of SiGe/Si thermistor material have been investigated. Finally, an uncooled thermistor material with TCR of −4.5%/K for 100 μm × 100 μm pixel sizes and low noise constant (K_1/f) value of 4.4 × 10⁻¹⁵ is presented. The outstanding performance of the devices is due to Ni silicide contacts, smooth interfaces, and high quality multi quantum wells (MQWs) containing high Ge content.     

Terahertz emission of SiGe/Si quantum wells

THz emission of stimulated character was observed in Si/SiGe/Si quantum well (QW) structures doped with boron. The resonance cavity formed by extremely parallel-structure planes due to total internal reflection, is necessary for the emission. The mechanism for the possible population inversion of strain-split acceptor levels is proposed.