肖特基质谱仪

肖特基（Ｓｃｈｏｔｔｋｙ）精密质量谱仪,是建立在ＧＳＩ所（当今核研究的领导所）电子冷却存储环（ＥＳＲ）上的精密质量谱仪,它对轻中量核与重核的测量精度Δｍ／ｍ分别达到５×１０－６,和５×１０－７．该谱仪为非阻挡型极灵敏的,甚至可测出一个裸核的测量设备,是冷却存储环束流诊断的可靠仪器,又是一台作核反应和核谱学研究的精密质量测定的谱仪． A Schottky precise mass spectroscope in light medium and in heavier nuclei with the mass resolution of Δm/m=5×10-6　　　　　　　　　　　　　　　　　　or 5×10-7, respectively,has been successfully built up and operated well at ESR ( Experimental Storage Ring cooled by electron beam) in G SI,the leading nuclear research institute.The spectroscope is anon stop of the beam type with quite sensitive,even one nucleus can be measured,set up that is a beam diagnosis relia ble instrument for the cooling beam in ESR...     

Direct probing of Schottky barriers in Si nanowire Schottky barrier field effect transistors

This work elucidates the role of the Schottky junction in the electronic transport of nanometer-scale transistors. In the example of Schottky barrier silicon nanowire field effect transistors, an electrical scanning probe technique is applied to examine the charge transport effects of a nanometer-scale local top gate during operation. The results prove experimentally that Schottky barriers control the charge carrier transport in these devices. In addition, a proof of concept for a reprogrammable nonvolatile memory device based on band bending at the Schottky barriers will be shown.     

Al Schottky contact on p-GaSe

A new Schottky diode, Al/p-GaSe, was presented in this study. It shows an effective barrier height of 0.96 eV with an ideality factor of 1.24 over five decades and a reverse leakage current density of 4.12×10⁻⁷ A/cm² at −2 V after rapid thermal annealing at 400 C for 30 s. The generation–recombination effect of the Schottky diode was decreased as the annealing temperature was increased. The formation of Al_1.33Se₂ was observed by X-ray diffraction analysis after the diode was annealed at 400 C for 30 s. Owing to the grains’ growth, the surface morphology of the 400 C-annealed diode was rougher than that of the unannealed diode, which was observed both by the AFM and the SEM analysis.     

Phonon-assisted tunneling in Schottky barriers

Experimental current-voltage characteristics and their temperature dependencies for AlGaAs Schottky barrier structures are shown to be in agreement with the recent theory of phonon-assisted tunneling.     

势垒可调的氧化镓肖特基二极管

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.     

DNA-based organic-on-inorganic semiconductor Schottky structures

A sandwich device has been fabricated from DNA molecular film by solution processing located between Al and p-type silicon inorganic semiconductor. We have performed the electrical characteristics of the device such as current–voltage (I–V), capacitance–voltage (C–V) and capacitance–frequency (C–f) at room temperature and in dark. The DNA-based structure has showed the rectifying behavior. From its optical absorbance spectrum, it has been seen that DNA has been a semiconductor-like material with wide optical band energy gap of 4.12 eV and resistivity of 1.6 × 10¹⁰ Ω cm representing a p-type conductivity.     

ZnO肖特基势垒紫外探测器

以p-Si(111)为衬底,用水热法首次制得六棱微管ZnO。并以此为有源区利用平面磁控溅射技术沉积得到Ag叉指状电报,从而制作了Ag／n-ZnO肖特基势垒结紫外探测器。对该紫外光探测器的暗电流和365nm波长光照下的光电流、光响应和量子效率进行了测试。测试结果表明：Ag和ZnO六棱管间已形成肖特基接触．其有效势垒高度为0．35eV。无光照时,暗电流很小,当用λ=365nm的光照射Ag/n-ZnO肖特基结时．在5．9V偏压时,光生电流分别为25．6,57．9μA。Ag／n-ZnO紫外探测器有明显的光响应特性和较高的量子效率,在366nm波长处,光响应度达到最大值0．161A／W,量子效率为54．7％。     

ICTS measurements for p-GaN Schottky contacts

High-temperature isothermal capacitance transient spectroscopy (H-ICTS) measurements were conducted to characterize near mid-gap defects, which are the origin of the memory effect in Ni/p-GaN Schottky contacts. A large single peak was detected only under the forward bias conditions. This indicates that the defects were located in the vicinity of the interface. The change of the peak height and position of the ICTS curves under various bias conditions were qualitatively interpreted by the distribution of the defects and the current flow effect.     

肖特基结的制备与势垒测量

采用磁控溅射方法在Nb07％-SrTiO3基片上制作Au薄膜接触,并在氧气气氛下750℃退火30 min,在室温环境下测量电流电压和电容电压等特性曲线,观测整流特性,根据相应实验数据采用饱和电流法、电容C-2与反偏电压V成线性关系计算肖特基势垒的大小.     

Electrical characteristics of Pt-ZnO Schottky nano-contact

The electrical characteristics of Pt-ZnO Schottky nano-contact have been studied. Well aligned ZnO nanorod arrays were synthesized by two-step wet-chemical method. A Pt-coated conducting probe of atomic force microscope was placed on the head face of the ZnO nanorod, thereby forming a Pt-ZnO nano-contact. The I-V characteristic curve shows that the Pt-ZnO nano-contact exhibits rectifying effect, like a Schottky diode with an ideality factor of 3.2 and a reverse-bias breakdown voltage more than -10 V. The st...     

CSRe的 Schottky束流诊断系统的研制

 介绍了Schottky信号的产生原理。研制了CSRe的Schottky束流诊断系统,该系统由一对平行的Schottky电极板、四分之一波螺旋谐振腔、低噪声放大器及数据获取系统组成。利用能量为481.88 MeV/u的⁷⁸Kr³⁶⁺束流对Schottky束流诊断系统进行灵敏度测试。结果表明该系统能够测量流强大于82 nA的束流。     

GaAs Schottky devices for submillimeter wavelengths

Conclusion The above analyses assume the absence of excess noise in the Schottky barrier mixer diode. Achievement of such a condition is dependent not only on the absence of interfacial stress in the device structure, but also on device surface properties. Reduction of excess noise caused by these two mechanisms is discussed by Sherrill, et al.,⁽¹⁰⁾ and Kattman, et al.⁽¹¹⁾ Minimum conversion loss in the THz range occurs for mixer diode with the smallest possible junction capacitance. This capacitance can be reduced along with the R_s, C_j(0) product by decreasing the device area and increasing the active layer impurity concentration. It was shown above that this impurity concentration increase will (a) permit higher frequency of operation, (b) cause a lower intrinsic conversion loss, and (c) be responsible for an increase in mixer diode I–V slope parameter, V₀. The only potentially negative effect comes from (c), but the analysis reviewed in the last section shows that an increase in V₀ has a minimal effect on mixer noise temperature for terahertz range operation. Experimental results of Dr. H. P. Röser⁽¹²⁾ to frequencies as high as 2.5 THz are in agreement with these predictions.It is thus concluded on the basis of the above four analyses of device mixer noise temperature and conversion loss that reasonable Schottky barrier mixer diode operation can be expected to at least 10 THz.This work was supported in part by the National Science Foundation under Grant ECS-8412477     

Photoluminescence ofn-GaAs at transparent Schottky contacts

Near-bandgap photoluminescence at 300 K of a Se-dopedn-GaAs crystal withn=4.8·10¹⁶ cm⁻³ was measured at a transparent CrAu−GaAs Schottky contact. The dependence of the luminescence intensity on the applied reverse voltage was recorded. Both the doping concentration and absorption coefficients above bandgap are determined.     

White-light emission from porous-silicon-aluminum Schottky junctions

Summary Porous-silicon-based white-light-emitting devices are presented. The fabrication process on different substrates is described. The peculiarities of technological steps for device fabrication (porous-silicon formation and aluminum treatment) are underlined. Doping profile of the porous layer, current-voltage characteristics, time response, lifetime tests and electroluminescence emission spectrum of the device are presented. A model for electrical behaviour of Al/porous silicon Schottky junction is presented. Electroluminescence spectrum of the presented devices showed strong similarities with white emission from crystalline silicon junctions in the breakdown region. Paper presented at the III INSEL (Incontro Nazionale sul Silicio Emettitore di Luce), Torino, 12–13 October 1995.     

Electrical properties of metal-GaAs Schottky barriers

Schottky barrier contacts have been fabricated by vacuum evaporation of thin films of six different metals (Mg, In, Al, Au, Bi and Sb) onto chemically cleaned n-type GaAs substrates. Bi and Sb contacts on GaAs have been reported for the first time. The contacts were examined for their C-V and I-V characteristics. The diodes exhibit near ideal characteristics for all the metals with values of the ideality factor n ranging from 1.06 to 1.1. The values of the barrier height obtained from C-V measurements could be brought into agreement with those obtained from I-V measurements only when the ideality factor was also included in the expression of the saturation current. By employing the most recent and reliable values of metal work function φ_M, the dependence of barrier height on φ_M has been investigated and an estimate of the surface state density and the Fermi level at the GaAs surface has been made. The surface state density obtained from this analysis is significantly larger than that reported by previous workers.