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基于对制作在n-GaN上的肖特基二极管的变温I-V测试和C-V测试,采用表面势垒减薄模型对肖特基二极管的电流输运特性进行了研究.试验结果表明,肖特基接触的电流输运机理非常复杂,在不同的温度条件和偏压条件下有着不同的电流输运机理.在此基础上对肖特基接触I-V特性方程进行了修正,得到了很好的拟合曲线.试验表明,高温I-V法提取的势垒高度与常温C-V法提取的势垒高度接近于根据金属功函数得出的理论势垒高度值.
关键词:
氮化镓
肖特基二极管
表面势垒减薄模型
热电子场发射 相似文献
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基于对制作在n-GaN上的肖特基二极管的变温,I-V测试和C-V测试,采用表面势垒减薄模型对肖特基二极管的电流输运特性进行了研究.试验结果表明,肖特基接触的电流输运机理非常复杂,在不同的温度条件和偏压条件下有着不同的电流输运机理.在此基础上对肖特基接触,I-V特性方程进行了修正,得到了很好的拟合曲线.试验表明,高温I-V法提取的势垒高度与常温C-V法提取的势垒高度接近于根据金属功函数得出的理论势垒高度值. 相似文献
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《物理学报》2020,(13)
本文制备了基于机械剥离β-Ga_2O_3的Ni/Au垂直结构肖特基器件,对该器件进行了温度特性I-V曲线测试.器件表现出了良好的二极管特性,随着温度从300 K升高至473 K,势垒高度从1.08 e V上升至1.35 e V,理想因子从1.32降低至1.19,二者表现出了较强的温度依赖特性,这表明器件的肖特基势垒存在势垒高度不均匀的问题.串联电阻随温度升高而降低,这主要是热激发载流子浓度升高导致的.本文利用势垒高度的高斯分布对器件的温度特性进行了修正,修正后的势垒高度为1.54 e V,理查孙常数为26.35 A·cm~(–2)·K~(–2),更接近理论值,这表明利用高斯分布势垒高度的热电子发射模型能够很好地解释Au/Ni/β-Ga_2O_3肖特基二极管的I-V温度特性问题,这种方法更适合用来测量β-Ga_2O_3肖特基二极管的电学参数. 相似文献
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理论研究了铁磁/有机半导体肖特基接触时的电流自旋极化注入,并讨论了电流自旋极化率随界面处肖特基势垒高度、有机半导体层中特殊载流子及其迁移率、界面附近掺杂浓度的变化关系.通过计算发现,寻找在势垒区中载流子迁移率比较大的有机半导体材料对实现有效的自旋注入是必要的;同时还发现,由于铁磁/有机半导体接触而形成的肖特基势垒不利于自旋注入.因此要想实现有效的自旋注入,界面附近必须采用重掺杂来有效减少势垒区的宽度,且势垒的高度要限制在一定的范围内. 相似文献
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测量了晶格匹配InAlN/GaN异质结肖特基接触的反向变温电流-电压特性曲线,研究了反向漏电流的偏压与温度依赖关系.结果表明:1)电流是电压和温度的强函数,饱和电流远大于理论值,无法采用经典热发射模型解释;2)在低偏压区,数据满足ln(I/E)-E1/2线性依赖关系,电流斜率和激活能与Frenkel-Poole模型的理论值接近,表明电流应该为FP机制占主导;3)在高偏压区,数据满足ln(I/E)-E1/2线性依赖关系,电流斜率不随温度改变,表明Fowler-Nordheim隧穿机制占主导;4)反向电流势垒高度约为0.60 eV,远低于热发射势垒高度2.91 eV,表明可导位错应是反向漏电流的主要输运通道,局域势垒由于潜能级施主态电离而被极大降低. 相似文献
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研究了恒压应力下超薄栅氧化层n型金属-氧化物-半导体场效应晶体管(n-MOSFET)软击穿 后的导电机制.发现在一定的栅电压Vg范围内,软击穿后的栅电流Ig符合Fowl er-Nordheim隧穿公式,但室温下隧穿势垒b的平均值仅为0936eV,远小于S i/Si O2界面的势垒高度315eV.研究表明,软击穿后,处于Si/SiO2界 面量子化能级上的 电子不隧穿到氧化层的导带,而是隧穿到氧化层内的缺陷带上.b与缺陷带能 级和电 子所处的量子能级相关;高温下,激发态电子对隧穿电流贡献的增大导致b逐 渐降低.
关键词:
软击穿
栅电流
类Fowler-Nordheim隧穿
超薄栅氧化层 相似文献
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氧化镓作为新一代宽禁带材料,其器件具有优越的性能.本文仿真研究了n~+高浓度外延薄层对氧化镓肖特基二极管的势垒调控.模拟结果显示,当n型氧化镓外延厚度为5 nm、掺杂浓度为2.6×1018 cm-3时,肖特基二极管纵向电流密度高达496.88 A/cm~2、反向击穿电压为182.30 V、导通电阻为0.27 mΩ·cm~2,品质因子可达123.09 MW/cm~2.进一步研究发现肖特基二极管的性能与n~+外延层厚度和浓度有关,其电流密度随n~+外延层的厚度和浓度的增大而增大.分析表明,n~+外延层对势垒的调控在于镜像力、串联电阻及隧穿效应综合影响,其中镜像力和串联电阻对势垒的降低作用较小,而高电场下隧穿效应变得十分显著,使得热发射电流增大的同时,隧穿电流得到大幅度提升,从而进一步提升了氧化镓肖特基二极管的性能. 相似文献
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Using polarization field effect-based thermionic field emission (PFE-TFE) model based on current–voltage–temperature data, possible carrier transport mechanisms for Pt/Au and Cr/Pd Schottky contacts to Al0.25Ga0.75N/GaN layers were investigated. Thermionic emission (TE) model was also investigated to compare to the PFE-TFE. It was shown that Schottky barrier heights (SBHs) are significantly affected by a polarization field-induced carrier density of the AlGaN layer. In addition, relatively little temperature dependence on the leakage current density of both contacts was found, which is in good agreement with the PFE-TFE model. The results indicate that the TFE is responsible for the current flow across the metal/AlGaN–GaN interface at T ≥ 293 K. 相似文献
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Detailed current–voltage–temperature (I–V–T) measurements were performed on the Schottky diodes fabricated on MOVPE-grown n-GaN layers. A large deviation from the thermionic emission (TE) transport was observed in the reverse I–V curves with a large excess leakage. From the calculation based on the thermionic-field emission (TFE) model, it was found that the tunneling plays an important role in the carrier transport across the GaN Schottky barrier even for doping densities as low as 1×1017 cm−3. A novel barrier-modified TFE model based on presence of near-surface fixed charges or surface states is proposed to explain the observed large reverse leakage currents. 相似文献
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Mahesh Kumar Basanta Roul Mohana K. Rajpalke Thirumaleshwara N. Bhat A.T. Kalghatgi S.B. Krupanidhi 《Current Applied Physics》2013,13(1):26-30
The temperature dependent electrical transport behavior of n–n InGaN/Si heterostructures grown by plasma-assisted MBE was studied. Structural characteristics of the as-grown InGaN epilayers were evaluated high resolution X-ray diffraction and composition of InGaN was estimated from photoluminescence spectra using standard Vegard's law. Current density–voltage plots (J–V–T) revealed that the ideality factor (η) and Schottky barrier height (SBH) (Φb) are temperature dependent and the incorrect values of the Richardson's constant (A7) produced, suggests an inhomogeneous barrier at the heterostructure interface. The higher value of the ideality factor compared to the ideal value and its temperature dependence suggest that the current transport is mainly dominated by thermionic field emission. 相似文献
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对Ti/6H-SiC Schottky结的反向特性进行了测试和理论分析,提出了一种综合的包括SiC Schottky结主要反向漏电流产生机理的反向隧穿电流模型,该模型考虑了Schottky势垒不均匀性、Ti/SiC界面层电压降和镜像力对SiC Schottky结反向特性的影响,模拟结果和测量值的相符说明了以上所考虑因素是引起SiC Schottky结反向漏电流高于常规计算值的主要原因.分析结果表明在一般工作条件下SiC Schottky结的反向特性主要是由场发射和热电子场发射电流决定的. 相似文献
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The effects of inductively coupled plasma (ICP) etching on electrical properties of Pt/Au–Al0.45Ga0.55N Schottky contacts are investigated. There are two linear parts in the ln I–V curves of ICP-etched Schottky contacts at small forward currents at 198–298 K. Thermionic field emission (TFE) theory analysis shows that Schottky contact with ICP etching has much lower barrier height and higher tunnel transmission probability than that without ICP etching, which could be attributed to plasma damage introduced on the ICP-etched surface. The down linear part is probably connected to surface tunneling component originated from plasma-etched surface which joins Schottky area to Ohmic area. 相似文献
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以La施主掺杂SrTiO_3(La STO)单晶为样品,制备了Pt/LaSTO/In结构存储器件.通过一系列电学测试,发现该器件具有稳定的多级阻变现象,最大开关比为10~4;高低阻电流-电压关系曲线的拟合分析表明,高阻时存在界面势垒,而低阻时满足电子隧穿模型特性.电子顺磁共振研究表明LaSTO单晶内存在带正电的空穴缺陷中心.综合分析证明器件的高低阻之间的转变由界面空位缺陷导致的电子俘获与去俘获引起.此外发现光照会对LaSTO单晶的阻值产生影响.该实验结果为LaSTO单晶在阻变存储器件中的应用提供了理论和技术指导. 相似文献
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A.H.M. Shousha 《Solid State Communications》1981,40(6):647-649
It is shown that the ratio between tunneling and Schottky thermionic emission currents in MIM structures exhibits a minimum at an applied voltage determined by the structure parameters. For appropriate parameters, the dominant transport mechanism can change from tunneling to Schottky thermionic emission and back to tunneling with increasing applied voltage. 相似文献
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The influences of InGaN/GaN multiple quantum well (MQW) heterostructures with InGaN/GaN and GaN barriers on carrier confinement were investigated. The degree of disordering over a broad range of temperatures from 20 to 300 K was considered. The optical and electrical properties were strongly influenced by structural and compositional disordering of the InGaN/GaN MQW heterostructures. To compare the degree of disordering we examined the temperature dependence of the luminescence spectra and electrical conductance contingent on the Berthelot-type mechanisms in the InGaN/GaN MQW heterostructures. We further considered carrier transport in the InGaN/GaN disordered systems, probability of carrier tunneling, and activation energy of the transport mechanism for devices with InGaN/GaN and GaN barriers. The optical properties of InGaN/GaN disordered heterosystems can be interpreted from the features of the absorption spectra. The anomalous temperature-dependent characteristics of the disordered InGaN/GaN MQW structures were attributable to the enhancement of the exciton confinement. 相似文献
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P. S. Anil Kumar R. Jansen O. M. J. vant Erve R. Vlutters S. D. Kim J. C. Lodder 《Physica C: Superconductivity and its Applications》2001,350(3-4):166-170
Here we present the realization of a room temperature operating spin-valve transistor with huge magnetocurrent (MC=300%) at low fields. This spin-valve transistor employs hot-electron transport across a Ni81Fe19/Au/Co spin valve. Hot electrons are injected into the spin valve across a Si–Pt Schottky barrier. After traversing the spin valve, these hot electrons are collected using a second Schottky barrier (Si–Au), which provides energy and momentum selection. The collector current is found to be extremely sensitive to the spin-dependent scattering of hot electrons in the spin valve, and therefore on the applied magnetic field. We also illustrate the role of the collector diode characteristics in determining the magnetocurrent under collector bias. 相似文献
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为探究常态环境下氧空位对单根SnO_2纳米线电输运性能的影响,采用化学气相沉积法合成了SnO_2纳米线,通过光刻微加工技术构筑了Au/单根SnO_2纳米线/Au二端纳米器件.将单根SnO_2纳米器件进行氢化处理,测试其在空气与真空中的伏安特性曲线,发现单根SnO_2纳米线在空气和真空环境中呈现异常不同的电输运特性:在空气中,加偏压注入电子会使通过纳米器件的电流减小,Au电极与SnO_2纳米线之间的接触势垒增大;抽真空后,在偏压的影响下,通过纳米器件的电流增大,Au/SnO_2交界面的接触方式由肖特基接触转变成欧姆接触.实验分析表明,影响单根SnO_2纳米线电输运特性行为的因素与纳米线表面的氧原子吸附与脱吸附所引起的氧空位浓度的变化有关.为进一步分析氧空位浓度变化的作用,利用第一性原理计算方法计算了氧空位浓度对SnO_2纳米线电输运性能的影响,通过分析体系的能带结构、态密度及Au/SnO_2接触界面的I-V曲线和透射谱,发现随着氧空位浓度的增大,SnO_2纳米线的带隙变小.同时,氧空位缺陷使Au/SnO_2接触界面处电子透射率增大,体系电输运能力变强.该研究结果将为集成纳米功能器件的设计提供一种新思路. 相似文献