共查询到19条相似文献,搜索用时 218 毫秒
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基区Ge组分的加入可以改善SiGe HBT的直流特性、 频率特性和噪声特性, 但Ge组分及其分布对HBT热学特性的影响报道还很少. 本文利用SILVACO半导体器件仿真工具, 建立了多指SiGe HBT模型, 对基区具有不同Ge组分梯度结构的SiGe HBTs的热学特性和电学特性的热稳定性进行了研究. 研究发现, 在Ge组分总量一定的条件下, 随着Ge组分梯度的增大, 器件的特征频率明显提高, 增益β和特征频率fT随温度变化变弱, 器件温度分布的均匀性变好, 但增益变小; 而基区均匀Ge组分(Ge组分梯度为零) 的HBT的增益较大, 但随温度的变化较大, 器件温度分布的均匀性也较差. 在此基础上, 将基区Ge组分均匀分布和Ge组分缓变分布相结合, 提出了兼顾器件热学特性、 增益特性和频率特性的新型基区Ge组分分布- 分段分布结构. 结果表明, 相比于基区Ge组分均匀分布的器件, 新器件温度明显降低; β和fT保持了较高的值, 且随温度的变化也较小, 显示了新结构器件的优越性. 这些结果对HBT的热学设计具有重要的参考意义, 是对SiGe HBT性能研究的一个补充. 相似文献
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本文结合1/f噪声信号功率谱随频率成反比变化的关系, 以及稀疏分解可以根据信号灵活构造原子库的特点, 提出一种基于稀疏分解估计大功率半导体激光器1/f噪声的新方法, 构造了具备1/f噪声特点的过完备库. 在该过完备库中通过Matching Pursuit(MP)算法完成了白噪声与1/f噪声混叠信号的稀疏分解. 实验结果显示:该方法估计出淹没在白噪声环境中1/f噪声的γ 参数, 与频谱分析仪的测量结果有较好的一致性, 通过对比不同的过完备库证明了所构造的过完备库的优越性. 相似文献
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在肖特基二极管(schottky barrier diode,SBD)辐照损伤机理和总剂量效应分析的基础上,利用1/f噪声的迁移率涨落和载流子数涨落模型,深入研究辐照损伤对器件1/f噪声的影响.研究结果表明,辐照诱生新的界面态,改变界面态密度分布,进而调制了肖特基势垒高度,增大表面复合速度是引起器件性能退化主要原因,也是1/f噪声剧烈增加的主要原因.正因为如此,噪声与器件退化存在相关性,即噪声拟合参数B越大,偏离标准值越多,器件可靠性越差,抗辐照能力越低,在辐照环境下工作越容易失效.由此可知,1/f噪声特性可以用作SBD辐照损伤机理的研究工具,并有可能用于SBD抗辐射加固的无损评估. 相似文献
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在肖特基二极管(Schottky barrier diode,SBD)辐照损伤机理和总剂量效应分析的基础上,利用1/f噪声的迁移率涨落和载流子数涨落模型,深入研究辐照损伤对器件1/f噪声的影响. 研究结果表明,辐照诱生新的界面态,改变界面态密度分布,进而调制了肖特基势垒高度,增大表面复合速度是引起器件性能退化主要原因,也是1/f噪声剧烈增加的主要原因. 正因为如此,噪声与器件退化存在相关性,即噪声拟合参数B越大,偏离标准值越多,器件可靠性越差,抗辐照
关键词:
肖特基二极管
f噪声')" href="#">1/f噪声
60Co γ射线')" href="#">60Co γ射线
界面态 相似文献
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首先测量了GaN肖特基二极管的正向变温电流-电压特性,研究了其电流输运机制,然后分析了在不同注入电流条件下的低频噪声行为.结果表明:1)在正向高电压区,热发射机制占主导,有效势垒高度约为1.25 eV;2)在正向低偏压区(V <0.8 V),与位错相关的缺陷辅助隧穿电流占主导,有效势垒高度约为0.92 eV (T=300 K);3)在极小电流(I <1μA)和极低频率(f <10 Hz)下,洛伦兹型噪声才会出现;电子的渡越时间取决于多个缺陷对电子的不断捕获和释放过程,典型时间常数约为30 ms (I=1μA);4)在更高频率和电流下,低频1/f噪声占主导;电流的输运主要受到势垒高度的随机波动的影响,所对应的系数约为1.1. 相似文献
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The discharge characteristics and the parameters of the cathode plasma in a two-stage ion source with a grid plasma cathode and a magnetic trap in the anode region are investigated. It is shown that an increase in the gas pressure and the accompanying increase in the reverse ion current in the bipolar diode between the cathode and anode plasmas lead to an increase in the cathode plasma potential and a transition of the cathode into the regime of electron emission from the open plasma boundary. The dependence of the ion current extracted from the anode plasma on the area of the exit aperture of the hollow cathode and the mesh size of the grid plasma cathode is explained. The conditions at which the ion emission current from the anode plasma is maximum are determined. The potential difference at the bipolar diode is measured by using the probe method. It is shown that, when the gas pressures reaches a critical value determined by the mesh size of the grid plasma cathode, the discharge passes into a contracted operating mode, in which the ion current extracted from the anode plasma decreases severalfold. 相似文献
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William D. Greason 《Journal of Electrostatics》2008,66(11-12):602-608
The effect of charge injection due to human body model (HBM) electrostatic discharge (ESD), charged device model (CDM) ESD and triboelectrification in capacitive microelectromechanical systems' (MEMS) structures is analyzed. The results show that as feature size is reduced, the effect remains constant for charging by triboelectrification. However, HBM ESD injected charge produces a change which is inversely proportional to the square of the gap separation and CDM ESD injected charge produces a change which is inversely proportional to the square of the plate area. 相似文献
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用发射光谱法测量氮气直流辉光放电的转动温度 总被引:2,自引:2,他引:2
本文报道了氮气气压分别为10和20Pa时,对直流辉光放电的发射光谱进行测量和分析的结果。选择的研究对象为N2放电中形成的N2^ B^2∑u^ →X^2∑g^ 跃迁的Δv=v′-v″=0谱带系中v′=0→v″=0谱带的R支。在阴极背面辉光区、阴极鞘层区、正柱区以及阳极辉光区中分别选择一点进行了转动分辨的发射光谱的测量。利用自己编写的光谱拟合程序,获得了相应的实验条件下N2^ 的转动温度,给出了转动温度随放电电压的变化趋势,其结果可以用直流放电的帕邢定律得到很好的解释。在10和20Pa气压下,放电的阴极鞘层区、正柱区、阳极辉光区中的转动温度都随放电电压呈现出了不同的变化趋势,甚至是完全相反的变化趋势。我们认为这是由于气压不同时,放电状态不同所致:气压为10Pa时的放电是正常辉光放电,而气压为时20Pa的放电为反常辉光放电。 相似文献
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The results of the investigation of the glow discharge time and space development in the neon‐filled diode at 1.33 mbar are presented. The glow is of the diffusion type with saturation current value of 0.2 mA. The temporal development of the light intensity, emitted perpendicularly on the diode axis from many different parts of the diode, is registered. Using this temporal development, the spatial development of the emitted light is examined. Electrically registered (by the oscilloscope) the total current through the diode reaches the saturation for 1.5 ms, which corresponds to the classical presumption of the formative time delay. The prebreakdown current is registered measuring the emitted light from diode gap. The investigation of light shows the increase of excitation in the gap at least 3 ms before any significant current has been registered (I < 1 µA). The negative glow appears in the diode gap near the anode and in the next a few milliseconds covers the cathode indicating the presence of the multiplication processes in the diode. The stationary regime in the diode is established for about 10 ms. Using this detection method, three stages of the discharge formation can be easily distinguished. These results indicate that the prebreakdown processes in the diode gap can be associated with the first stage of the breakdown formation. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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研究了低电压的人体模型(HBM)静电放电(ESD)对微电子器件造成的潜在失效。分别从CB结和EB结对2SC3356晶体管施加低电压HBM的ESD应力,结果表明:从CB结施加低电压的ESD电应力,所产生的潜在失效的几率要高于从EB结施加低电压的ESD电应力产生的潜在失效几率,即CB结比EB结对低电压的ESD应力引入的潜在失效更为敏感。高温(≥125 ℃)寿命实验有退火效应,从而缓解了低电压的ESD应力使器件产生的潜在损伤,使静电放电过程中引入的潜在损伤自恢复。 相似文献
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Puchkarev V.F. Bochkarev M.B. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1997,25(4):593-597
Vacuum discharge burning between a broad cathode and a point anode made of Mo, Cu, and Cd has been studied. This discharge operates in anode vapors and shows major arc characteristics, although no craters were examined on the cathode. The secondary electron emission is involved to explain current transport within the cathode region. This discharge is interpreted as a high density low voltage glow discharge. Having discussed the present and previous findings, the conclusion has been drawn that the secondary electron emission and “hump of potential” are dominant in the vacuum arc cathode spot 相似文献
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阳极杆箍缩二极管(RPD)具有小焦斑、高亮度的特点,是闪光X光机领域的研究热点。基于Marx发生器和脉冲形成线技术路线产生1 MV高电压脉冲驱动RPD,开展了不同结构参数二极管实验研究。基于RPD物理过程的数值模型,分析了结构参数对箍缩物理过程的影响。研究表明在1 MV电压下,RPD阴极等离子体平均扩散速度、阳极等离子体平均扩散速度分别为2,0.6 cm/μs时,该模型可以较好地描述实验结果。在阳极杆直径一定的情况下,二极管数值模型表明减小阴极孔径可以使二极管更快进入强箍缩状态,但过小的阴极孔径会导致二极管间隙过早闭合。 相似文献