Design rules for field plate edge termination in SiC Schottkydiodes

Practical design of silicon carbide (SiC) Schottky diodes incorporating a field plate necessitates an understanding of how the addition of the field plate affects the performance parameters and the relationship between the diode structure and diode performance. In this paper, design rules are presented for SiC Schottky diodes that incorporate field plate edge termination. The use of an appropriate field plate edge termination can improve the reverse breakdown voltage of a SiC Schottky diode by a factor of two. Reverse breakdown voltage values can be obtained that are up to 88% of the theoretical maximums     

混合PiN/Schottky二极管的研究

对混合PiN/Schottky二极管（MPS）进行研究,首先对MPS二极管的工作原理进行了分析,通过对MPS二极管、肖特基二极管、PIN二极管的伏安特性进行模拟,结果表明MPS二极管正向压降小,电流密度大,反向漏电流小,是一种具有肖特基正向特性和PN结反向特性的新型整流器。可以通过改变肖特基和PN结的面积比来调整MPS二极管的性能,与肖特基二极管和PIN二极管相比具有明显的优势,是功率系统不可或缺的功率整流管。     

高性能Si基MOS肖特基二极管式氢气传感器研究

报道了采用NO直接氧化制备氮化氧化物作为绝缘层制备高性能Si基MOS肖特基二极管式气体传感器(SDS)的技术。实验结果显示，MOS肖特基二极管式气体传感器具有高的响应灵敏度和好的响应重复性，可以探测浓度约为10^-6的氢气。因此，采用NO直接氧化法制备绝缘层是一种制备高可靠、高灵敏度Si基MOS SDS的技术。     

A novel silicon Schottky diode for NLTL applications

The design and simulation of a novel silicon Schottky diode for nonlinear transmission line (NLTL) applications is discussed in this paper. The Schottky diode was fabricated on a novel silicon-on-silicide-on-insulator (SSOI) substrate for minimized series resistance. Ion implantation technology was used as a low-cost alternative to molecular beam epitaxy to approximate the delta (/spl delta/) doping profile, which results in strong nonlinear CV characteristics. The equivalent circuit model of the Schottky diode under reverse bias conditions was extracted from the S-parameter measurement performed on the diode. The measured CV characteristics show strong nonlinearity, the junction capacitance varies from 182 to 47.5 fF as the reverse bias voltage is varied from 0 to -5 V. A parasitic inductance of 40 pH was measured for the silicon Schottky diode, which is much smaller than a comparable sized GaAs Schottky diode. This small inductance is an advantage for the silicon Schottky diode offering improvement in the silicon NLTL performance.     

Performance of W-InSb Metal-Semiconductor Point-Contact Diodes as Detectors and Mixers in the Near Infrared

Metal-Insulator-Metal (MIM) and Schottky-barrier diodes have been used extensively in the past years as harmonic generators and mixers for frequency measurements in the spectral range from the far-infrared to the visible. MIM diodes present a very low fabrication cost and are easy to handle, while Schottky diodes are mechanically more stable and long-lived. In the present work we discuss the performance of a metal-semiconductor point-contact diode for the radiation around 1 μm. This device, which may be viewed as a hybrid between a MIM and a Schottky diode, combines the simplicity and easiness of fabrication of the MIM diode with the stability and the long contact life typical of the Schottky diode. It proved to be very efficient even for visible light.     

Temperature behaviour and compensation of Schottky barrier diode

This paper offers a fresh look into the temperature behaviour and compensation of Schottky barrier diode's radio frequency (RF) resistance. RF resistance of a Schottky diode varies with temperature at conventional fixed current bias as well as fixed voltage bias condition. Here we have proposed “optimum load-line biasing technique” to achieve temperature invariant RF performance of the Schottky diode based RF circuits. Mathematically we have shown and verified by measurements that the proposed technique provides temperature insensitive RF performance over a very wide range of operating temperature. Thus, without any separate temperature sensor and compensation circuits, as used in conventional temperature-compensation schemes, it is possible to achieve temperature invariant RF performance of the Schottky diode based RF circuits.     

太赫兹准光混频器的设计与实现

设计了一种用于太赫兹接收机的准光混频器。该混频器主要由肖特基二极管集成平面天线和高阻硅透镜2部分组成,其中肖特基二极管的截止频率为3.5 THz。平面双缝天线、螺旋天线、对数周期天线分别与肖特基二极管进行一体化集成,再通过高阻硅透镜来消除介质表面波,以达到改善天线辐射性能的目的。所设计的准光混频器工作频率为340 GHz,并对该混频器的检波性能、方向图和混频性能进行了测试,其变频损耗小于15 dB。     

Study of the effect of various parameters on nonlineartransmission-line (NLTL) performance

Nonlinear transmission-line (NLTL) shock-wave generator performance in the presence of frequency-dependent losses is reported. The skin effect is studied using the harmonic-balance technique with the aid of the HP-MDS design database language. Measured results of a 48-section NLTL excited by a 26.6-dBm sinusoidal signal from the literature are compared with simulation with good agreement. Experimental performance of an eight-section GaAs monolithic-microwave integrated circuit NLTL is reported for 26-dBm drive conditions. Schottky diode capacitance-voltage (C-V) characteristics are computed using the Silvaco physical simulator for different doping profiles. Doping profiles are used as a parameter in NLTL design and their effect on NLTL performance is investigated. S-parameter measurements are performed for the GEC Marconi Materials Technology GaAs Schottky diode family from which the C-V characteristics are extracted and used to validate simulation. The problem of variable dynamic range is addressed and variable diode areas are used to enhance matching     

Effect of Inverse Doped Surface Layer in Schottky Barrier Modification: A Numerical Study

Poisson’s equation and the drift–diffusion equations are used to simulate the current–voltage characteristics of a Schottky diode with an inverse doped surface layer. The potential inside the bulk semiconductor near the metal–semiconductor contact is estimated by simultaneously solving these equations, and then current as a function of bias through the Schottky diode is calculated. The Schottky diode parameters are extracted by fitting of simulated data to the thermionic emission diffusion equation. The simulation is carried out for various inverse layer thicknesses and doping concentrations. The obtained diode parameters are analyzed to study the effect of the inverse layer thickness and doping concentration on Schottky diode modification and its behavior at low temperatures. It is shown that an increase in the inverse layer thickness and doping concentration leads to Schottky barrier height enhancement and a change in the ideality factor. The temperature dependences of the Schottky barrier height and ideality factor are also studied.     

太赫兹肖特基二极管技术研究进展

太赫兹肖特基二极管是太赫兹应用领域中非常重要的一种器件,它可以实现高频信号的混频和倍频,研制发展太赫兹肖特基二极管对于太赫兹技术有重要意义。本文首先介绍了太赫兹肖特基二极管的种类及性能表征,接着介绍国内外主要研究机构在太赫兹肖特基二极管方面的研制成果和进展,最后总结出研制太赫兹肖特基二极管的关键技术和发展方向。     

Effect of deep impurity levels on Schottky barrier diode characteristics

In the presence of an arbitrary number of deep donor levels volt-ampere and volt-farad characteristics are obtained for the Schottky barrier diode which contains a thin dielectric layer between the metal and the semiconductor. The analysis of these characteristics shows that the deep levels can significantly influence both the capacitance and the rectifying properties of the Schottky diode; the thicker the dielectric layer, the greater the effect of the deep levels upon volt-ampere relationship and the lesser upon volt-farad one. One can determine the parameters of the deep levels from these relationships. The results of the calculation are in agreement with the data of the experiment performed.     

Power Schottky diode design and comparison with the junction diode

Because the Schottky diode is a one-carrier device, it has both advantages and disadvantages with respect to the junction diode which is a two-carrier device. The advantage is that there are practically no excess minority carriers which must be swept out before the diode blocks current in the reverse direction. The disadvantage of the Schottky diode is that for a high voltage device it is not possible to use conductivity modulation as in the pin diode; since charge carriers are of one sign, no charge cancellation can occur and current becomes space charge limited. The Schottky diode design is developed in Section 2 and the characteristics of an optimally designed silicon Schottky diode are summarized in Fig. 9. Design criteria and quantitative comparison of junction and Schottky diodes is given in Table 1 and Fig. 10. Although somewhat approximate, the treatment allows a systematic quantitative comparison of the devices for any given application.     

Numerical simulation study of current–voltage characteristics of a Schottky diode with inverse doped surface layer

The Poisson’s equation and drift–diffusion equations are used to simulate the current–voltage characteristics of Schottky diode with an inverse doped surface layer. The potential inside the bulk semiconductor near the metal–semiconductor contact is estimated by simultaneously solving these equations, and current as a function of bias through the Schottky diode is calculated for various inverse layer thicknesses and doping concentrations. The Schottky diode parameters are then extracted by fitting of simulated current–voltage data into thermionic emission diffusion equation. The obtained diode parameters are analyzed to study the effect of inverse layer thickness and doping concentration on the Schottky diode parameters and its behavior at low temperatures. It is shown that increase in inverse layer thickness and its doping concentration give rise to Schottky barrier height enhancement and a change in the ideality factor. The temperature dependences of Schottky barrier height and ideality factor are studied. The effect of temperature dependence of carrier mobility on the Schottky diode characteristics is also discussed.     

Report on 4H–SiC JTE Schottky diodes

4H–SiC Schottky diodes with and without Junction Terminate Extension (JTE) have been fabricated using Ni for contact and boron for p+ implant. Electrical characterization showed a rectifying behaviour in the on-state. In the reverse mode, the un-terminated Schottky diode demonstrated a breakdown voltage of approximately 200 V, while the JTE structure exhibited a significant improved breakdown performance, and the blocking voltage over 450 V. Optical microscope examination revealed the surface flashover failure located at the metal contact periphery for the un-terminated Schottky diode, while the JTE structure failed in the central area of the metal contact. Both the experimental and theoretical analyses confirmed the JTE structure enhancement on the reliability for SiC Schottky diode performance in reverse mode.     

Schottky barrier parameters and structural properties of rapidly annealed Zr Schottky electrode on p-type GaN

The Schottky barrier junction parameters and structural properties of Zr/p-GaN Schottky diode are explored at various annealing temperatures. Experimental analysis showed that the barrier height (BH) of the Zr/pGaN Schottky diode increases with annealing at 400℃ (0.92 eV (I-V)/1.09 eV (C-V)compared to the asdeposited one (0.83 eV (I-V)/0.93 eV (C-V). However, the BH decreases after annealing at 500℃. Also, at different annealing temperatures, the series resistance and BH are assessed by Cheung''s functions and their values compared. Further, the interface state density (N_SS)of the diode decreases after annealing at 400℃ and then somewhat rises upon annealing at 500℃. Analysis reveals that the maximum BH is obtained at 400℃, and thus the optimum annealing temperature is 400℃ for the diode. The XPS and XRD analysis revealed that the increase in BH may be attributed to the creation of Zr-N phases with increasing annealing up to 400℃. The BH reduces for the diode annealed at 500℃, which may be due to the formation of Ga-Zr phases at the junction. The AFM measurements reveal that the overall surface roughness of the Zr film is quite smooth during rapid annealing process.     

The performance of GaAs field-effect transistors as microwave mixers

The performance of Schottky barrier gate field-effect transistors (FET's) as single-ended microwave mixers at 3 GHz is described. An increase in dynamic range of approximately 10 dB over conventional diode mixers is reported although the noise figures of FET miters at present are higher than for diode mixers.     

Enhancement of effective barrier height in Ti-silicon Schottky diode using low-energy ion implantation

Increasing the effective barrier height in a Ti-p-type silicon Schottky diode has been achieved by means of low-energy ion implantation to introduce a thin inversion layer on silicon substrate. It is shown theoretically that effective barrier height equal to the energy bandgap can be obtained in such structure if the thickness and dopant density of the implanted layer are properly chosen. Experimental results for several titanium (Ti) on phosphorus implanted p-type silicon Schottky diodes show that effective barrier heights were increased from 0.6 eV for the Ti-p Si Schottky diode to 0.96 eV for a Ti-n-p-Si Schottky diode with a phosphorus-implanted layer thickness of 400 Å and dose of 1.26 × 10¹²cm^-2. Good agreement is obtained between the calculated and the measured barrier height for several Ti-n-p silicon Schottky diodes.     

Frequency multipliers for millimeter and submillimeter wavelengths

Theory and tools for analysis and design of millimeter- and submillimeter-wave multipliers are discussed. Experimental work is reviewed. The Schottky diode model at submillimeter frequencies, use of Schottky multiplier chains versus direct higher-order multipliers, and the effect of cooling on Schottky diode multipliers are discussed. Alternative diodes such as the high electron mobility varactor (HEMV), the barrier-intrinsic-n⁺ diode (BIN), the barrier-n-n⁺ diode (BNN), the quantum well diode (QWD), and the single barrier varactor (SBV) are discussed, with attention given to their potential submillimeter frequency multipliers     

Terahertz Sub-harmonic Mixer Using Discrete Schottky Diode for Planetary Science and Remote Sensing

Sub-harmonic mixers are the core element of terahertz room temperature, high spectral resolution heterodyne receivers for planetary science, and remote sensing. Here, terahertz sub-harmonic mixer up to 400 GHz using discrete Schottky diode is presented. Measured performance is in agreement with results from the linear and nonlinear co-simulations, and this methodology shows its practicability for the discrete planar GaAs Schottky diode-based terahertz core circuit design.     

Schottky diode for bipolar LSI's consisting of an impurity-controlled Si substrate and Al(2%Si) electrode

Circuit design conditions of Schottky diodes have been investigated and the fabrication method for diodes suitable for the conditions has been proposed for applications to bipolar LSI's, such as ECL RAM and Schottky TTL. It has been found that the desired Schottky diode for bipolar LSI's is not an ideal device from the theoretical point of view. Desired built-in voltage, ideal factor, series resistance, and junction capacitance for the Schottky diode have been estimated, respectively, for the bipolar RAM and Schottky TTL. A proposed Schottky diode consists of an impurity-concentration-controlled