基于SiC衬底的氧化镓外延薄膜生长及其特性研究

Gallium oxide(b-Ga2O3) is a very attractive new semiconductor for power device applications because of its extremely large band-gap of 4.8-4.9eV. The break down field of Ga2O3 is estimated to be 8MV/cm, which is about three times larger than those of 4H-SiC and GaN. Baliga's figure of merit(FOM) , which is a basic parameter showing how suitable a material is for power devices, is proportional to the cube of the breakdown field, but only linearly proportional to the electron mobility and dielectric constant. Therefore, Baliga's FOM of b-Ga2O3 is at least four times larger than those of 4H-SiC or GaN. The theoretical limits of on-resistance as a function of breakdown voltage for these semiconductors, as calculated by using the parameters. These estimates indicate that Ga2O3 power devices would outperform 4H-SiC and GaN ones. In this project, the generation and transformation mechanism of on defects in Ga2O3/4H-SiC layers will be carried out with theoretical and experimental methods. Firstly, the defects will be simulated with Materials Studio software from the first principle, and the model will be set up with theoretical analysis and experimental results. Secondly, the defects in Ga2O3/4H-SiC layers will be characterized with cathode luminescence spectra, scanning electron microscope and TEM.On the base of the model and characterization of the defect mechanism, the process of Ga2O3/4H-SiC layers, such as the power, temperature, pressure and gas flow parameters will be optimized. And the high quality Ga2O3/4H-SiC layers will be achieved with the method of defects controlling. The study of Ga2O3/4H-SiC layers growth has important academic significance and application. The development of Ga2O3 high power electronic devices may be promoted with the method of defects controlling, which could provide a theoretical base for the development of a new generation of Ga2O3-based power devices.

Ga2O3具有巴利加优值较高，在制造相同耐压的单极功率器件时，导通电阻比较小，可以有效的提高能源转换效率，极大地促进能源节约型社会的建设进程。Ga2O3薄膜的质量的优劣（缺陷多少）直接决定了Ga2O3电力电子器件的性能。本项目采用理论和实验相结合的方法，建立出Ga2O3/4H-SiC薄膜中缺陷的产生和转化模型，揭示缺陷的演化变化规律，提出Ga2O3/4H-SiC薄膜中缺陷的控制方法；优化Ga2O3/4H-SiC薄膜生长技术，生长出高质量Ga2O3/4H-SiC薄膜薄膜，并制备出相同结构的高功率4MESFETs原型，验证薄膜中缺陷的演化机理和缺陷控制方法。本项目在Ga2O3/4H-SiC薄膜中缺陷的产生、转化机理和缺陷控制方法等方面寻求突破现有研究瓶颈，制备出高质量的Ga2O3薄膜，有望促进Ga2O3高功率电力电子器件的发展，为新一代Ga2O3基功率器件的发展做出贡献。

Ga2O3具有巴利加优值较高，在制造相同耐压的单极功率器件时，导通电阻比较小，可以有效的提高能源转换效率，极大地促进能源节约型社会的建设进程。Ga2O3薄膜的质量的优劣直接决定了Ga2O3电力电子器件的性能。本项目采用理论和实验相结合的方法，建立出Ga2O3/4H-SiC薄膜中缺陷的产生和转化模型，揭示缺陷的演化变化规律，提出Ga2O3/4H-SiC薄膜缺陷的控制方法；优化Ga2O3/4H-SiC薄膜生长技术，生长出了高质量Ga2O3/4H-SiC薄膜薄膜，并制备出相同结构的高功率4MESFETs原型，验证薄膜中缺陷的演化机理和缺陷控制方法。本项目在Ga2O3/4H-SiC薄膜中缺陷的产生、转化机理和缺陷控制方法等方面寻求突破现有研究瓶颈，制备出高质量的Ga2O3薄膜，有望促进Ga2O3高功率电力电子器件的发展，为新一代Ga2O3基功率器件的发展做出贡献。依托本项目，已通讯作者发表论文sci论文14篇，其中ESI高引论文一篇；申请中国发明专利7项，获得授权一项；申请美国专利一项。培养硕士研究生4名，已毕业2名；博士研究生2名，已毕业1名。