垂直结构氮化镓电力电子器件研制中的关键材料制备工艺研究

我国发展节能高技术提升竞争力亟需高端电力电子器件为支撑。宽禁带半导体氮化镓是当前研制高端电力电子器件性能最优材料，尽管同质外延垂直结构GaN电力电子器件已展现优于现有Si和SiC器件性能，却因器件成品率低制备成本高而难以实用化应用。本项目重点开展三方面最关键材料制备工艺研究。一是通过探索合适应力调控结构，实现HVPE-GaN单晶厚膜衬底低应力低位错密度高成品率复制，解决HVPE-GaN衬底残余应力对器件成品率和性能的影响；二是通过改进HVPE反应室设计提升降速HVPE工艺生长的GaN材料纯度及膜层均匀平整度，进而替代常规MOCVD工艺实现器件性能和制备效率提升；三是通过探索合适弱键合解耦合结构，实现垂直结构GaN电力电子器件薄膜化制备与完整大面积剥离转移，剥离下来的GaN单晶衬底重复利用又进一步降低器件制备成本。为发展自主知识产权且适合产业化推广的高端GaN电力电子器件制备生产技术奠定基础

The development of high quality power devices is the fundamental task to improve the competitive power of energy saving technology in our country. Wide bandgap semiconductor GaN is one of the best materials to develop high quality power electronic devices. Although the vertical GaN power electronic devices based on homoepitaxy exhibit better performance than the silicon and SiC based devices, its high cost and low yield make it hard to practical application. In this project, we focus mainly on the three most critical aspect of the material growth. First, the proper stress modulation structure will be studied to realize low stress, dislocation density, and high yield HVPE-GaN single crystalline thick films, in order to eliminate the impact of residual stress of HVPE-GaN substrates on the device yield and performance. Second, The HVPE reactor well be improved to obtain high purity and smooth GaN films, and subsequently improve the device performance and product efficiency by substituting MOCVD. Third, the weak-bond buffer layer will be studied to realize the complete, large area separation and transference of GaN based power electronic devices from the GaN single crystalline substrates, which can be reused to further decrease the device fabrication cost. Our project is very important to realize the independent intellectual property rights and commercialization of high quality GaN power electronic devices.