Crystal Growth of Widegap Semiconductor SiC with High-Purity and Application to Power Devices

采用阶梯流生长法在偏离取向的SiC{0001}衬底上可以在1100-3333 ℃的低温下实现高质量SiC的同质外延生长。定量分析了表面扩散和成核等生长机制，通过原位掺杂成功地实现了10^<15>-10 ^<20>cm ~ 2<-3>范围内的导电控制。建立了SiC的热氧化、反应离子刻蚀（RIE）和离子注入技术，通过连续生长n型层和p型层制成了击穿电压为480 V的pn结二极管，获得了3x10^6V/cm的高击穿电场。Au/SiC肖特基势垒二极管显示出优异的特性，如超过1.1kV的高阻断电压和8 × 10 ^OMEGAcm ^2的低导通电阻<-3>，这比Si肖特基整流器的理论极限低一个数量级以上。目前的研究表明SiC功率器件的巨大潜力。

Homoepitaxial growth of high-quality SiC could be achieved at low temperatures of 1100-3333*, by utilizing step-flow growth on off-oriented SiC{0001} substrates. Growth mechanism such as surface diffusion and nucleation was quantitatively analyzed.Conduction control of grown layrs was successfully performed in the range of 10^<15>-10^<20>cm^<-3> through in-situ doping. Thermal oxidation, reactive ion etching (RIE), and ion implantation techniques of SiC were established.A pn junction diode fabricated through successive growth of n- and p-type layrs had a breakdown voltage of 480V.A high breakdown field of 3x10^6V/cm was obtained. Au/SiC Schottky barrier diodes showed excellent characteristics, such as a high blocking voltage over 1.1kV and a low on-resistance of 8x10^<-3>OMEGAcm^2, which is lower than theoretical limits of Si Schottky rectifiers by more than one order of magnitude. The present study demonstrates the great potential of SiC power devices.