共查询到19条相似文献,搜索用时 359 毫秒
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Si/Si1—x Gex异质结双极晶体管和Si双极晶体管高频性能的比较分析 总被引:1,自引:0,他引:1
本文介绍了对Si/Si1-x Gex异质结双极晶体管(HBT)和硅双极结晶体管(BJT)高频性能进行模拟比较的结果,其结构参数是为获得最高fT≈fmax设计的,模拟研究表明,(1)Si/Si1-xGex HBT具有64GHz的峰值fT(=fmax),它比Si BJT提高了16.4%,(2)发射极充电时间对,高频性能有相当大的影响,即使电流密度高达80kAcm^-2时也是如此;(3)SiGe基区组分梯度和基区掺杂分布强烈影响着fT和fmax,研究发现高斯梯度分布具有最高的峰值fT=fmax,据估计其峰值截止频率比均匀掺杂分布高30%。(4)高频性能对集电极设计的依赖关系表明,要在fT,fmax和BVCBO间进行折衷处理,并且(5)通过降低发射区或基区掺要浓度,可设计出fT超过100GHz的Si1-xGexHBT,同样,通过提高基区掺杂浓度和降低非本征电容和电阻,可实现100GHz的fmax. 相似文献
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版图尺寸对SiGe/Si HBT高频噪声特性的影响 总被引:1,自引:0,他引:1
从实验上研究了版图尺寸对Si/SiGe HBT高频噪声特性的影响。结果表明,在现有工艺条件下,减少外基区电阻(即减少发射极与基区间距),对降低高频噪声很显著。增加基极条数、增加条长也可减少基极电阻,降低高频噪声。发射极条宽从2μm减少为1μm,对噪声的改善很有限。对1μm或2μm条宽,40μm条长的5个基极条或9个基极条的SiGe HBT,在片测试表明,频率从0.4 GHz增加到1.2 GHz,噪声系数在2.5~4.6 dB之间变化。 相似文献
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在对红外热像仪的测量中,噪声是评价红外热像仪性能的主要参数。噪声参数包括时间域噪声和空间域噪声,时间域噪声可分为高频时间噪声和低频时间噪声(即1/f噪声);空间域噪声可分为高频空间噪声(即固定模式噪声FPN)和低频空间噪声(非均匀性噪声)。对高频时间噪声和低频时间噪声进行了严格的区分和定义;给出了在短时间内忽略低频时间噪声时高频噪声NETD的计算模型;在不忽略低频时间噪声时计算高频噪声等效温差的数学计算模型和测量方法;对高频时间域NETD测量结果进行了不确定度分析与评价。 相似文献
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噪声是DC/DC变换器重要的性能指标,它限制了其在高精密电子系统中的应用。DC/DC变换器的噪声分为高频噪声和低频噪声。高频噪声包括电流纹波与热噪声。低频噪声主要成分有1/f噪声和散粒噪声。高频噪声直接影响产品性能,低频噪声除了与产品性能有关之外,还与产品质量和可靠性密切相关。本文在详细研究DC/DC变换器低频噪声测量技术的基础上,完成了对国产军用DC/DC变换器低频噪声的测量。实验结果表明,1/f噪声和散粒噪声是DC/DC变换器低频噪声的主要成分。基于此实验结果,本文对DC/DC变换器低频噪声的产生机理进行了分析,并进一步讨论了低频噪声作为DC/DC变换器质量与可靠性诊断工具可行性。 相似文献
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目前,应变Si1-xGex薄膜材料杂质浓度尚未有准确且简便易行的测试方法。为了快速准确地确定应变Si1-xGex薄膜材料的掺杂浓度,在研究应变Si1-xGex材料多子迁移率模型的基础上,采用Matlab编程模拟仿真,求解并建立了不同Ge组分下应变Si1-xGex薄膜材料掺杂浓度与其电阻率的关系曲线,讨论了轻、重掺杂两种情况下该关系曲线的变化趋势。通过Si1-xGex薄膜材料样品的四探针电阻率测试及电化学C-V掺杂浓度测试的对比实验,对本关系曲线进行了验证。 相似文献
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本文主要介绍新颖的Si_(1-x)Ge_x/Si异质结内光电发射长波红外探测器和焦平面阵列的现状、典型结构、性能参数及制备技术. 相似文献
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采用减压化学气相淀积(RPCVD)技术在弛豫Si_(1-x)Ge_x虚拟衬底上赝晶生长应变硅层,以其为沟道材料制造得到的应变硅n-MOSFET表现出显著的性能提升。研究了通过改变Si_(1-x)Ge_x中Ge的摩尔组分x以改变硅帽层中的应变以及在器件制造流程中通过控制热开销来避免应变硅层发生弛豫等关键问题。在室温下,相对于体硅器件,应变硅器件表现出约87%的低场电子有效迁移率增强,在相同的过驱动电压下,饱和漏端电流增强约72%。在293 K到353 K的温度范围内研究了反型层电子有效迁移率和饱和漏端电流随温度的变化,实验结果表明,当温度升高时应变硅材料的电子迁移率增强倍数保持稳定。 相似文献
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Calculations were performed on the band edge levels of (111)-biaxially strained Si on relaxed Si_(1-x)Ge_x alloy using the k·p perturbation method coupled with deformation potential theory. The results show that the conduction band (CB) edge is characterized by six identicalvalleys, that the valence band (VB) edge degeneracies are partially lifted, and that both the CB and VB edge levels move up in electron energy as the Ge fraction (x) increases. In addition, the dependence of the indirect bandgap and the VB edge splitting energy on x was obtained. Quantitative data from the results supply valuable references for Si-based strained device design. 相似文献
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Pei-Wen Li Wei-Ming Liao Ching-Chieh Shih Tine-Shang Kuo Li-Shyue Lai Yang-Tai Tseng Tsai M.-J. 《Electron Device Letters, IEEE》2003,24(7):454-456
We have investigated the effect of substrate biasing on the subthreshold characteristics and noise levels of Si/Si/sub 1-x/Ge/sub x/ (x=0,0.15,0.3) heterostructure MOSFETs. A detailed analysis of the dependence of threshold voltage, off-state current, and low-frequency noise level on the substrate-source (V/sub bs/) biasing showed that SiGe heterostructure MOSFETs offer a significant speed advantage, an extended subthreshold operation region, a reduced noise level, and reduced bulk potential sensitivity compared to Si bulk devices. These experimental results demonstrate that SiGe heterostructure MOSFETs render a promising extension to the CMOS technologies at the low-power limit of operation, eventually making the micropower implementation of radio frequency (RF) functions feasible. 相似文献
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使用超高真空磁控溅射系统在p-Si上制备了铂铱硅(Pt_xIr_(1-x)Si)薄膜,并制作了Pt_xIr_(1-x)Si/p-Si红外探测器,研究了探测器在3~5 μm波段的特性,结果表明,Pt_xIr_(1-x)Si/p-Si势垒高度为0.177 eV,相应红外探测器截止波长为7.0μm.与普通铂硅红外探测器相比,铂铱硅红外探测器在3~5μm中波红外波段响应明显增强.Abstract: Ultra thin Pt_xIr_(1-x)Si films were deposited on p-Si substrates with ultra high vacuum sputtering system and Pt_xIr_(1-x)Si /p-Si(100) Schottky barrier detectors were fabricated and the characteristics of the detectors operating in the wavelength range of 3 ~ 5 μm were studied, with the barrier height of 177 meV and cutoff wavelength of 7. 0 μm. compared with ordinary Pt-Si IR detectors, Pt_xIr_(1-x)Si detectors have a much higher response at 3~5 μm MWIR spectral range. 相似文献
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Tsung-Hsi Yang Guangli Luo Chang E.Y. Tsung-Yeh Yang Hua-Chou Tseng Chun-Yen Chang 《Electron Device Letters, IEEE》2003,24(9):544-546
The properties of nickel silicide formed by depositing nickel on Si/p/sup +/-Si/sub 1-x/Ge/sub x/ layer are compared with that of nickel germanosilicide on p/sup +/-Si/sub 1-x/Ge/sub x/ layer formed by depositing Ni directly on p/sup +/-Si/sub 1-x/Ge/sub x/ layer without silicon consuming layer. After thermal annealing, nickel silicide on Si/p/sup +/-Si/sub 1-x/Ge/sub x/ layer shows lower sheet resistance and specific contact resistivity than that of nickel germanosilicide on p/sup +/-Si/sub 1-x/Ge/sub x/ layer. In addition, small junction leakage current is also observed for nickel silicide on a Si/p/sup +/-Si/sub 1-x/Ge/sub x//n-Si diode. In summary, with a Si consuming layer on top of the Si/sub 1-x/Ge/sub x/, the nickel silicide contact formed demonstrated improved electrical and materials characteristics as compared with the nickel germanosilicide contact which was formed directly on the Si/sub 1-x/Ge/sub x/ layer. 相似文献