共查询到20条相似文献,搜索用时 171 毫秒
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基于非选择性外延,自对准注入技术,集电区选择性注入和快速热退火工艺,提出了一种适用于1.5μm BiCMOS集成技术的SiGe HBT器件结构。该结构具有内基区薄,外基区厚,B/E结两侧杂质浓度低,发射极/基极自对准诸优点。利用TSuprem4和Medici进行工艺模拟和电学特性仿真。结果表明,所设计的的SiGe HBT具有良好的电学特性,其最大电流增益为210,当Vce=2.5 V时,截止频率达到65 GHz,验证了器件结构设计的合理性。 相似文献
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SiGe HBT器件的研究设计 总被引:1,自引:0,他引:1
研制了一种平面集成多晶发射极SiGe HBT,并对SiGe HBT设计进行了研究分析。给出了双极晶体管的结构和关键工艺参数,并进行了流片测试,结果表明,在室温下电流增益β大于1500,最大达到3000,Vceo为5V,厄利电压VA大于10V,βVA乘积达到15000以上。这种器件对多晶Si发射极As杂质浓度分布十分敏感。 相似文献
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基于器件结构特点和电学特性,研究了影响SiGe HBT(异质结双极晶体管)直流电流增益的主要因素,分析了不同的电流密度条件下,器件的物理参数、结构参数与集电极电流密度和中性基区复合电流的关系,建立了SiGe HBT集电极电流密度,空穴反注入电流密度、中性基区复合电流、SRH(Shockley-Read- Hall)复合电流密度、俄歇复合电流密度以及直流电流增益模型,对直流电流增益模型进行了模拟仿真,分析了器件物理、结构参数以及复合电流与直流电流增益的关系,得到了SiGe HBT直流电流增益特性的优化理论依据. 相似文献
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A new analytical model for the base current of Si/SiGe/Si heterojunction bipolar transistors(HBTs) has been developed. This model includes the hole injection current from the base to the emitter, and the recombination components in the space charge region(SCR) and the neutral base. Distinctly different from other models, this model includes the following effects on each base current component by using the boundary condition of the excess minority carrier concentration at SCR boundaries: the first is the effect of the parasitic potential barrier which is formed at the Si/SiGe collector-base heterojunction due to the dopant outdlffusion from the SiGe base to the adjacent Si collector, and the second is the Ge composition grading effect. The effectiveness of this model is confirmed by comparing the calculated result with the measured plot of the base current vs. the collector-base bias voltage for the ungraded HBT. The decreasing base current with the increasing the collector-base reverse bias voltage is successfully explained by this model without assuming the short-lifetime region close to the SiGe/Si collector-base junction, where a complete absence of dislocations is confirmed by transmission electron microscopy (TEM)[1]. The recombination component in the neutral base region is shown to dominate other components even for HBTs with a thin base, due to the increased carrier storage in the vicinity of the parasitic potential barrier at collector-base heterojunction. 相似文献
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A simple experimental technique is presented that enables the accurate extraction of the collector-base resistance rμ that models the impact of neutral base recombination on the ac output resistance of bipolar transistors. Measurements of ratios of rμ to the output resistance ro arising from the Early effect for SiGe HBTs allows for the quantitative determination of the impact of neutral base recombination on analog circuits that are designed to have a high output resistance. It is found that SiGe HBT structures indicative of those currently being used commercially in advanced analog processes exhibit neutral base recombination that is significant enough to severely degrade the output resistance of analog circuits, even when the output transistors experience ac base voltage drive conditions. Finally, it is shown how extraction of the ratio of r μ to ro can be a useful tool to determine the impact of parasitic potential barriers formed by boron out-diffusion at the collector-base junction on device and analog circuit performance 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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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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This work quantifies neutral base recombination in UHV/CVD SiGe heterojunction bipolar transistors (HBTs) using calibrated two-dimensional (2-D) simulation. The simulated collector-base conductance through neutral base recombination (NBR) modulation is far below the experimentally observed values, and hence does not explain the measured output resistance degradation under forced-IB operation. In spite of the output resistance degradation, these UHV/CVD SiGe HBTs have approximately the same base current as the silicon control, and hence higher current gain. Based on the observation of the majority carrier concentration limited recombination in the CB junction depletion layer, as opposed to the minority carrier concentration limited recombination in the neutral base, local presence of traps in the CB junction depletion layer is suggested. This explains the measured CB conductance modulation and the related output resistance degradation without compromising the current gain. Numerical simulations using traps locally introduced into the CB junctions successfully reproduced the measured collector-base conductance from simulation without appreciable degradation in current gain 相似文献
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Jin Tang Guofu Niu Joseph A.J. Harame D.L. 《Electron Devices, IEEE Transactions on》2004,51(9):1475-1482
This work investigates the impact of collector-base (CB) junction traps on low-frequency noise in high breakdown voltage (HBV) SiGe HBTs. By comparing the base current and 1/f noise at the same internal emitter-base (EB) voltage of the standard breakdown voltage (SBV) and HBV devices, we show that the CB junction traps not only increase base current, but also contribute base current 1/f noise when high injection occurs. The individual 1/f noise contributions from the emitter-base junction traps and from the collector-base junction traps are separated. The dependence of the 1/f noise component on the corresponding base current component is determined, and shown to be different for the EB and CB junction traps. The dependence of the total 1/f noise on the total base current, however, remains the same before and after high injection occurs in the HBV device, which is approximately the same as that for the SBV device. The I/sub B/ contribution from the CB junction recombination current needs to be modeled for accurate I-V and 1/f noise modeling. 相似文献
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Anteney I.M. Lippert G. Ashburn P. Osten H.J. Heinemann B. Parker G.J. Knoll D. 《Electron Device Letters, IEEE》1999,20(3):116-118
An electrical method is applied to SiGe and SiGe:C heterojunction bipolar transistors (HBTs) to extract the bandgap narrowing in the base layer and to characterize the presence of parasitic energy barriers in the conduction band, arising from boron transient enhanced out-diffusion from the SiGe layer. It is shown that a background carbon concentration within the base (≈1020 cm-3) eliminates parasitic energy barriers at the collector/base junction, and hence shows that transient enhanced diffusion of boron from the base has been completely suppressed 相似文献
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超结SiGe功率开关二极管可以克服常规Si功率二极管存在的一些缺陷,如阻断电压增大的同时,正向导通压降也将增大,反向恢复时间也变长。该新型功率二极管有两个重要特点:一是由轻掺杂的p型柱和n型柱相互交替形成超结结构,代替传统功率二极管的n-基区;二是p+区采用很薄的应变SiGe材料。该器件可以同时实现高阻断电压、低正向压降和快速恢复的电学特性。与相同器件厚度的常规Si功率二极管相比较,反向阻断电压提高了42%,反向恢复时间缩短了40%,正向压降减小了约0.1V(正向电流密度为100A/cm2时)。应变SiGe层中Ge含量和器件的基区厚度是影响超结SiGe二极管电学特性的重要参数,详细分析了该材料参数和结构参数对正向导通特性、反向阻断特性和反向恢复特性的影响,为器件结构设计提供了实用的参考价值。 相似文献
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Our basic approach is to develop a symmetrical design with equal delay times for collector, base and the total load to simulate the high frequency behaviour of SiGe heterobipolar transistors (HBTs). On this base we have investigated the feasibility of SiGe HBTs with transit frequencies fT above 200 GHz. A symmetrical design reaching fT=208 GHz is presented. The dependence of the high frequency behaviour on Ge content and vertical transistor design is shown. Critical parameters like the maximum current density and the breakthrough voltage are considered. An analytical model is compared to numerical simulations and experimental data. 相似文献