高压 Ti/ 6H- SiC肖特基势垒二极管（英文）

在N型6H-SiC外延片上，通过热蒸发，制作Ti/6H-SiC肖特基势垒二极管(SBD)。通过化学气相淀积，进行同质外延生长，详细测量并分析了肖特基二极管的电学特性，该肖特基二极管具有较好的整流特性。反向击穿电压约为400V，室温下，反向电压V_R=200V时，反向漏电流J_R低于1×10~(-4)A/cm~2。采用Ne离子注入形成非晶层，作为边缘终端，二极管的击穿电压增加到约为800V。

SiC纳米棒光学声子的喇曼光谱

报道了用光谱的手段研究SiC纳米棒(NR)的结果。对于在实验中观察到LO模的大幅度红移及新出现的喇曼峰，认为在类似SiC NR的存在大量缺陷的极性纳米材料中，结构缺陷对材料特性的影响比量子限制效应更为重要。理论计算证实了这一点，并解释了实验观察到的异常现象。

6H-SiC高反压台面pn结二极管

在可商业获得的单晶6H-SiC晶片上，通过化学气相淀积，进行同质外延生长；并在此6H-SiC结构材料上，利用反应离子刻蚀和接触合金化技术，制作台面pn结二极管。详细测量并分析了器件的电学特性，测量结果表明此6H-SiC二极管在室温、空气介质中，-10V时，漏电流密度为2.4×10~(-8)A/cm~2，在反向电压低于600V及接近300℃高温下都具有良好的整流特性。

使用 X射线衍射技术判定 Si C单晶体的结构和极性（英文）

使用四圆衍射仪和双晶衍射技术，分析了SiC体单晶的结构和极性。SiC单晶体由化学气相淀积法获得。六方{10-15}极图证明了该单晶结构为6H型。三轴晶衍射中的ω模式衍射强度的差异判定了该单晶的Si终端面和C终端面，即极性面。两个面的一、二、三级衍射强度的测量比值与经过散射因子修正后计算的结构振幅平方比值｜F(000L)｜~2/｜F(000-L)｜~2非常吻合。因此，利用极性面的衍射强度差异，可以方便、严格地判断具有类似结构如2H{0001}、4H{0001}及3C-SiC{111}的极性。

半导体SiC材料的外延生长

SiC具有禁带宽度大、热导率高、电子的饱和漂移速度大、临界击穿电场高和介电常数低等特点, 在高频、大功率、耐高温、抗辐照的半导体器件及紫外探测器和短波发光二极管等方面具有广泛的应用前景。本文简要介绍SiC半导体材料的液相外延、化学气相和分子束外延生长的概况及生长过程中杂质的控制。

SiC单晶的生长及其器件研制进展

SiC具有禁带宽度大、热导率高、电子的饱和漂移速度大、临界击穿电场高和介电常数低等物点。在高频、大功率、耐高温、抗辐照的半导体器件及紫外探测器和短波发光二极管等方面具有广泛的应用前景。该文综述了半导体SiC单晶和薄膜的生长及其器件研制的概况。

Study on photoluminescence spectra of SiC

于2010-11-23批量导入

Ti Schottky barrier diodes on n-type 6H-SiC

Using thermal evaporation, Ti/6H-SiC Schottky barrier diodes (SBD) were fabricated. They showed good rectification characteristics from room temperature to 200degreesC. At low current density. the current conduction mechanism follows the thermionic emission theory. These diodes demonstrated a low reverse leakage current of below 1 X 10(-4)Acm(-2). Using neon implantation to form the edge termination, the breakdown voltage was improved to be 800V. In addition. these SBDs showed superior switching characteristics.

Studies of 6H-SiC devices

Silicon carbide (SiC) is recently receiving increased attention due to its unique electrical and thermal properties. It has been regarded as the most appropriate semiconductor material for high power, high frequency, high temperature, and radiation hard microelectronic devices. The fabrication processes and characterization of basic device on 6H-SiC were systematically studied. The main works are summarized as follows:The homoepitaxial growth on the commercially available single-crystal 6H-SiC wafers was performed in a modified gas source molecular beam epitaxy system. The mesa structured p(+)n junction diodes on the material were fabricated and characterized. The diodes showed a high breakdown voltage of 800 V at room temperature. They operated with good rectification characteristics from room temperature to 673 K.Using thermal evaporation, Ti/6H-SiC Schottky barrier diodes were fabricated. They showed good rectification characteristics from room temperature to 473 K. Using neon implantation to form the edge termination, the breakdown voltage was improved to be 800 V.n-Type 6H-SiC MOS capacitors were fabricated and characterized. Under the same growing conditions, the quality of polysilicon gate capacitors was better than Al. In addition, SiC MOS capacitors had good tolerance to gamma rays. (C) 2002 Published by Elsevier Science B.V.

In situ doping of 3C-SiC grown on (0001) sapphire substrates by LPCVD

The heteroepitaxial growth of n-type and p-type 3C-SiC on (0001) sapphire substrates has been performed with a supply of SiH4+C2H4+H-2 system by introducing ammonia (NH3) and diborane (B2H6) precursors, respectively, into gas mixtures. Intentionally incorporated nitrogen impurity levels were affected by changing the Si/C ratio within the growth reactor. As an acceptor, boron can be added uniformly into the growing 3C-SiC epilayers. Nitrogen-doped 3C-SiC epilayers were n-type conduction, and boron-doped epilayers were p-type and probably heavily compensated.

Growth and structural properties of GaN films on flat and vicinal SiC(0001) substrates

Initial stage GaN growth by molecular-beam epitaxy (MBE) on SiC(0001) substrate is followed by in situ scanning tunneling microscopy. Comparison is made between growth on nominally flat and vicinal substrate surfaces and the results reveal characteristic differences between the two. Ex situ transmission electron microscopy (TEM) and X-ray diffraction (XRD) rocking curve measurements of the films show lower density of defects and better structural quality of the vicinal film. We suggest the improved structural quality of the vicinal film is related to the characteristic difference in its initial stage nucleation and coalescence proccsses than that of the flat film.

Photoluminescence of nanocrystalline SiC films prepared by rf magnetron sputtering

Amorphous Sic films are deposited on Si (111) substrates by rf magnetron sputtering and then annealed at 1200 degreesC for different times by a dc self-heating method in a vacuum annealing system. The crystallization of the amorphous Sic is determined by Raman scattering at room temperature and X-ray diffraction. The experimental result indicates that the Sic nanocrystals have formed in the films. The topography of the as-annealed films is characterized by atomic force microscopy. Measurements of photoluminescence of the as-annealed films show blue or violet light emission from the nanocrystalline Sic films and photoluminescence peak shifts to short wavelength side as the annealing time decreases.

Epitaxial growth of SiC on complex substrates

Epitaxial growth of SiC on complex substrates was carried out at substrate temperature from 1200 degreesC to 1400 degreesC. Three kinds of new complex substrates, c-plane sapphire, AlN/sapphire, and GaN/AlN/sapphire, were used in this study. We obtained a growth rate in the range of 1-6 mum/h. Thick (6 mum) SIC epitaxial layers with no cracks were successfully obtained on AlN/sapphire and GaN/AlN/sapphire substrates. X-ray diffraction patterns have confirmed that single-crystal SiC was obtained on these complex substrates. Analysis of optical transmission spectra of the SIC grown on sapphire substrates shows the lowest-energy gap near 2.2 eV, which is the value for cubic SiC. The undoped SIC showed n-type electrical conductivity. (C) 2001 Elsevier Science B.V. All rights reserved.

Homoepitaxial growth and device characteristics of SiC on Si-face (0001) 6H-SiC

Homoepitaxial growth of SiC on a Si-face (0 0 0 1) GH-SIC substrate has been performed in a modified gas-source molecular beam epitaxy system with Si2H6 and C2H4 at temperatures ranging 1000 1450 degreesC while keeping a constant SiC ratio (0.7) in the gas phase. X-ray diffraction patterns, Raman scattering measurements. and low-temperature photoluminescence spectra showed single-crystalline SiC. Mesa-type SiC p-n junctions were obtained on these epitaxial layers, and their I-V characteristics are presented. (C) 2001 Elsevier Science B.V. All rights reserved.