碳化硅双极结型晶体管的研究

There is urgent demand for high performance power electronics devices to satisfy the stringent requirements of power conversion applications. This project investigates the Silicon Carbide (SiC) Bipolar Junction Transistor (BJT)，which can overcome the performance limit of the conventional silicon power transistors and becomes one of the most attractive structures of SiC switching devices. The goal of the project is to solve the following bottleneck problems of SiC BJT. First, the reported specific on-resistance (Rsp) of SiC BJT is much larger than its theoretical limit. Second, the current capacity of SiC BJT is small. Third, the power loss of SiC BJT is large. Design optimization, processing and fabrication of 1200V SiC BJT will be carried out to reduce its specific on-resistance. The physical mechanism of SiC BJT’s switching will be studied, which is a combination of unipolar and bipolar devices. Much progress is expected to be made in the physical mechanism of parallel SiC BJTs’ switching, which is very helpful to greatly increase the current capability of SiC BJT and provides theoretical guidance for its applications in high power conversion. Based on the transfer characteristics of field effect transistors, a simple and novel intelligent dirver method is proposed to achieve high-efficiency use of SiC BJT. The project is expected to develop independent intellectual property rights of the large capacity and high performance SiC BJT and its efficient method of use. It can provide a feasible plan for the research of high voltage and large capacity SiC power devices.

为了满足电力换流技术对高性能电力电子器件的迫切需求，本项目选择打破传统硅基晶体管性能极限并且最具吸引力的SiC开关结构之一的双极结型晶体管（BJT）为研究对象，以解决国际上SiC BJT的导通比电阻（Rsp）远大于其理论值、器件电流容量小和驱动功耗大的瓶颈问题为目标，深入研究器件新结构设计理论和工艺制作方法，研制1200伏SiC BJT，实现Rsp的降低；研究SiC BJT兼具单极型和双极型器件开关物理机制的开关过程，在多个SiC BJT并联开关过程的基础理论上取得大的进展，为SiC BJT电流容量的提升及其在大容量电能转换领域的应用提供理论指南；利用场控晶体管的转移特性，研制简单新颖的SiC BJT等比例智能驱动，降低器件在轻负载工作时的驱动功耗。项目预期研发具有自主知识产权的高性能大容量SiC BJT及其高效使用方法，为我国SiC电力电子器件的的研发和产业化快速发展提供一个可行方案。

为了满足电力换流技术对高性能电力电子器件的迫切需求，本项目选择以碳化硅双极结型晶体管(SiC BJT)为研究对象，以解决SiC BJT的导通比电阻(Rsp)大于其理论值、器件电流容量小和驱动功耗大的瓶颈问题为目标。通过深入研究器件新结构设计理论和工艺制作方法，研制1200V SiC BJT，实现Rsp的降低和驱动损耗的减小，为我国SiC电力电子器件的的研发和产业化快速发展提供了一个可行方案。本研究首先探索了单个SiC BJT和多个SiC BJT并联在不同工况下的开关物理机制，并研究了不同电路杂散参数对器件开关过程的影响，为SiC BJT电流容量的提升及其在大容量电能转换领域的应用提供理论指南；然后研制了1200V SiC BJT样品，完成了项目要求的耐压能力等指标，并建立了SiC BJT的SPICE电路模型，为基于SiC BJT的电力电子系统设计与优化提供了有力的工具；最后设计了两款简单新颖的SiC BJT等比例智能驱动，大幅降低了SiC BJT的驱动损耗，为SiC BJT的高效安全使用提供了新的方法。该项目的研究成果为我国的电力电子器件及其应用发展提供了新的思路和发展方向，提升了我国在该领域的实力和影响力。