共查询到20条相似文献,搜索用时 15 毫秒
1.
Cressler J.D. Vempati L. Babcock J.A. Jaeger R.C. Harame D.L. 《Electron Device Letters, IEEE》1996,17(1):13-15
We report the first measurements of low-frequency noise in high-performance, UHV/CVD epitaxial Si- and SiGe-base bipolar transistors. The magnitude of the noise power spectral density at fixed frequency for both Si and SiGe devices is comparable for similar bias, geometry, and doping conditions, indicating that the use of strained SiGe alloys does not degrade transistor noise performance. The best recorded values of noise corner frequency were 480 Hz and 373 Hz for the Si and SiGe transistors, respectively, for multi-stripe devices with an emitter area of 0.5×10.0×3 μm2. A functional dependence of the noise power spectral density on base current for both device types of IB1.90 was observed, and noise measurements as a function of device geometry suggest that the contributing noise sources are uniformly distributed across the emitter of the transistors, not at the emitter periphery 相似文献
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以Si2H6和GeH4作为源气体,用UHV/CVD方法在Si(100)衬底上生长了Sil-xGex合金材料和Si1-xGex/Si多量子阱结构.用原子力显微镜、X光双晶衍射和透射电子显微镜对样品的表面形貌、均匀性、晶格质量、界面质量等进行了研究.结果表明样品的表面平整光滑,平均粗糙度为1.2nm;整个外延片各处的晶体质量都比较好,各处生长速率平均偏差为3.31%,合金组分x值的平均偏差为2.01%;Si1-xGex/Si多量子阱材料的X光双晶衍射曲线中不仅存在多级卫星峰,而且在卫星峰之间观察到了Pendellosung条纹,表明晶格质量和界面质量都很好;Si1-xGex/Si多量子阱材料的TEM照片中观察不到位错的存在. 相似文献
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UHV/CVD生长SiGe/Si异质结构材料 总被引:11,自引:5,他引:6
以 Si2 H6 和 Ge H4 作为源气体 ,用 UHV/CVD方法在 Si( 1 0 0 )衬底上生长了 Si1- x Gex 合金材料和 Si1- x Gex/Si多量子阱结构 .用原子力显微镜、X光双晶衍射和透射电子显微镜对样品的表面形貌、均匀性、晶格质量、界面质量等进行了研究 .结果表明样品的表面平整光滑 ,平均粗糙度为 1 .2 nm;整个外延片各处的晶体质量都比较好 ,各处生长速率平均偏差为 3.31 % ,合金组分 x值的平均偏差为 2 .0 1 % ;Si1- x Gex/Si多量子阱材料的 X光双晶衍射曲线中不仅存在多级卫星峰 ,而且在卫星峰之间观察到了 Pendellosung条纹 ,表明晶格质量和界面质量都很好 ;Si 相似文献
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Low-frequency noise characteristics of 0.1 μm Si1−xGex channel pMOSFETs were studied by numerical simulations in the framework of the carrier number fluctuation model as well as the correlated fluctuation in the mobility model. Simulation results predict that Si1−xGex channel pMOSFETs could offer improved low-frequency noise performance as compared to the conventional bulk Si devices. This improvement in Si1−xGex channel pMOSFETs could be attributed to less effective oxide trap density for noise generation due to the increasing separation of quasi-Fermi level and valence band edge at Si–SiO2 interface by Ge-induced band offset. 相似文献
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利用 Si H4 和 Ge H4 作为源气体 ,对 UHV/CVD生长 Si1- x Gex/Si外延层的表面反应机理进行了研究 ,通过 TPD、RHEED等实验观察了 Si( 1 0 0 )表面 Si H4 的饱和吸附、热脱附过程 ,得出 Si H4 的分解应该是每个 Si H4 分子的 4个 H原子全部都吸附到了 Si表面 ,Si H4 的吸附率正比于表面空位的 4次方 ,并分析了 Ge H4 的表面吸附机制 .在此基础上建立了 UHV/CVD生长Si1- x Gex/Si的表面反应动力学模型 ,利用模型对实验结果进行了模拟 ,二者符合得很好 相似文献
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利用SiH4和GeH4作为源气体,对UHV/CVD生长Si1-xGex/Si外延层的表面反应机理进行了研究,通过TPD、RHEED等实验观察了Si(100)表面SiH4的饱和吸附、热脱附过程,得出SiH4的分解应该是每个SiH4分子的4个H原子全部都吸附到了Si表面,SiH4的吸附率正比于表面空位的4次方,并分析了GeH4的表面吸附机制.在此基础上建立了UHV/CVD生长Si1-xGex/Si的表面反应动力学模型,利用模型对实验结果进行了模拟,二者符合得很好. 相似文献
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The equivalent base noise SIb of InP/InGaAs heterojunction bipolar transistors (HBT's) with a circular pattern emitter is investigated experimentally at a low frequency ranging from 10-105 Hz. The measured SIb exhibits the 1/f dependence in an overall frequency range without any accompanying burst noise. Furthermore, SIb varies as Ibγ for the base current Ib and as d-2 for the emitter diameter d, where the value of γ ranges from 1.62-1.72 depending on d of HBT's used. The 1/f noise model, which rigorously deals with the recombination current at the base surface Ibs as a function of Ib as well as of d is proposed. Applying our noise model to the dependence of SIb on Ib, as well as on d, reveals that even though γ is less than two, the origin of SIb is due to the recombination of electrons at the exposed base surface near the emitter edges. On the basis of theoretical considerations for the diffusion length of electrons and traps at the base surface, the Hooge parameter αH for the noise due to the base surface recombination is deduced to be in the order of 10 -2 for the first time 相似文献
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An ultrahigh vacuum chemical vapor deposition (UHV/CVD) system is introduced.SiGe alloys and SiGe/Si multiple quantum wells (MQWs) have been grown by cold-wall UHV/CVD using disilane(Si2H6) and germane (GeH4) as the reactant gases on Si(100) substrates.The growth rate and Ge contents in SiGe alloys are studied at different temperature and different gas flow.The growth rate of SiGe alloy is decreased with the increase of GeH4 flow at high temperature.X-ray diffraction measurement shows that SiGe/Si MQWs have good crystallinity,sharp interface and uniformity.No dislocation is found in the observation of transmission electron microscopy(TEM) of SiGe/Si MQWs.The average deviation of the thickness and the fraction of Ge in single SiGe alloy sample are 3.31% and 2.01%, respectively. 相似文献
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用于SiGeHBT器件的UHV/CVDn~-型硅外延研究 总被引:1,自引:0,他引:1
利用超高真空化学气相淀积(UHV/CVD)设备,在掺Asn+型Si衬底上生长了掺Pn-型Si外延层.用扩展电阻法分析了在不同的生长温度和PH3气体流量下生长的Si外延层的过渡区厚度.结果表明,生长温度对n+-Si衬底的As外扩有明显影响,在700℃下生长的Si外延层的过渡区厚度为0.16μm,而在500℃下仅为0.06μm,且杂质分布非常陡峭.X射线双晶衍射分析表明在700℃下生长的Si外延层的质量很高.制作的锗硅异质结晶体管(SiGeHBT)的击穿特性很硬,击穿电压为14.5V,在VCB=14.0V下的漏电流仅为0.3μA;输出特性很好,在VCE=5V,IC=3mA时的放大倍数为60 相似文献
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The collector-base junction avalanche multiplication factor (M-1) in SiGe HBTs is investigated using a new technique better tolerant to self-heating and collector-base leakage. The new technique provides higher accuracy at low current densities and enables M-1 to be measured at high current densities typically used in circuits. Comparisons with identically processed silicon control devices show that M-1 is not inadvertently increased by the incorporation of SiGe, despite its smaller bandgap. With cooling, M-1 first increases, and then saturates when T<117 K. A 2.3 V critical reverse CB voltage at which base current reversal occurs is observed down to 83 K, which is sufficiently high for today's bipolar and BiCMOS logic applications 相似文献
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利用超高真空化学气相淀积(UHV/CVD)设备,在掺As n+型Si衬底上生长了掺P n-型Si外延层.用扩展电阻法分析了在不同的生长温度和PH3气体流量下生长的Si外延层的过渡区厚度.结果表明,生长温度对n+-Si衬底的As外扩有明显影响,在700℃下生长的Si外延层的过渡区厚度为0.16μm,而在500℃下仅为0.06μm,且杂质分布非常陡峭.X射线双晶衍射分析表明在700℃下生长的Si外延层的质量很高.制作的锗硅异质结晶体管(SiGe HBT)的击穿特性很硬,击穿电压为14.5V,在 V CB =14.0V下的漏电流仅为0.3μA;输出特性很好,在 V CE =5V, I C=3mA时的放大倍数为60. 相似文献
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Hot electron and hot hole degradation of UHV/CVD SiGe HBT's 总被引:1,自引:0,他引:1
Gogineni U. Cressler J.D. Niu G. Harame D.L. 《Electron Devices, IEEE Transactions on》2000,47(7):1440-1448
We investigate the degradation in current gain and low-frequency noise of SiGe HBT's under reverse emitter-base stress due to hot electrons (forward-collector stress) and hot holes (open-collector stress). Contrary to previous assumptions we show that hot electrons and hot holes with the same kinetic energy generate different amounts of traps and hence have a different impact on device degradation. These results suggest that the accuracy of using forward-collector stress as an acceleration tool and reliability predictor must be carefully examined. We also present, for the first time, the effect of Ge profile shape on the reliability of SiGe HBT's, as well as discuss measurements on SiGe HBT's as a function of device geometry and temperature 相似文献
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超高真空化学气相生长用于应变硅的高质量SiGe缓冲层 总被引:4,自引:1,他引:3
采用UHV/CVD技术,以多层SiGe/Si结构作为缓冲层来生长应变弛豫SiGe虚衬底,并在此基础上生长出了具有张应力的Si层.利用高分辨X射线、二次离子质谱仪和原子力显微镜分别对薄膜的晶体质量、厚度以及平整度进行了分析.结果表明,通过这种方法制备的SiGe虚衬底,不仅可以有效提高外延层中Ge含量,以达到器件设计需要,而且保证很好的晶体质量和平整的表面.Schimmel液腐蚀后观察到的位错密度只有1×106cm-2. 相似文献
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Niu G. Cressler J.D. Zhang S. Gogineni U. Ahlgren D.C. 《Electron Devices, IEEE Transactions on》1999,46(5):1007-1015
This paper presents measurements of the avalanche multiplication factor (M-1) in SiGe HBTs using a new technique capable of separating the avalanche multiplication and Early effect contributions to the increase of collector current with collector-base bias, as well as allowing safe measurements at practical current densities. The impact of collector doping, current density, Ge profile, and operation temperature are reported for the first time using measured and simulated results from a production quality UHV/CVD SiGe HBT technology. Limitations of the technique in the presence of significant self-heating are discussed. By turning on the secondary hole impact ionization, we revealed the difference in impact ionization between strained SiGe and Si in the presence of the “dead space” effect. Despite its smaller bandgap, the compressively strained SiGe layer shows an apparent decrease in the secondary hole impact ionization rate compared to Si 相似文献
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Tashiro T. Tatsumi T. Sugiyama M. Hashimoto T. Morikawa T. 《Electron Devices, IEEE Transactions on》1997,44(4):545-550
A P-i-N SiGe/Si superlattice photodetector with a planar structure has been developed for Si-based opto-electronic integrated circuits. To make the planar structure, a novel SiGe/Si selective epitaxial growth technology which uses cold wall ultrahigh-vacuum/chemical vapor deposition has been newly developed. The P-i-N planar SiGe/Si photodetector has an undoped 30-Å Si0.9Ge0.1/320-Å Si, 30 periods, superlattice absorption layer, a 0.1-μm P-Si buffer layer, and a 0.2-μm P+-Si contact layer on a bonded silicon-on-insulator (ηext). The bonded SOI is used to increase the external quantum efficiency (ηext) of the photodetector. Moreover, a 63-μm deep/128-μm wide trench, to achieve simple and stable coupling of an optical fiber to the photodetector, is formed in the silicon chip. The P-i-N planar photodetector exhibits a high ηext of 25-29% with a low dark current of 0.5 pA/μm2 and a high-frequency photo response of 10.5 GHz at λ=0.98 μm 相似文献