摘要
由于材料自身的优异物理电学性质,宽带隙半导体碳化硅(SiC)高功率MOSFETs器件可以大幅度降低电力系统的能耗,成为电力电子器件领域的关注热点。然而SiC MOSFET器件中SiC/SiO2的界面态密度比Si/SiO2界面态密度高两个数量级左右,导致器件沟道迁移率较低,致使器件性能严重退化。碳元素的存在是过高界面态产生的关键因素,研究SiC MOSFET器件中SiC/SiO2界面附近碳的存在形式,可以更好的指导碳化硅氧化工艺,更好的发挥碳化硅器件优势。本文首先分析了SiC/SiO2高界面态的根本原因,接着结合国内外最新的理论研究进展,对碳元素的扩散及固定模型、氧化后碳元素的存在形态等模型建模及理论研究进行了综述,为改善SiC器件氧化工艺提供基础理论指导。
Wide band-gap semiconductor silicon carbide (SiC) high-power MOSFET can greatly reduce the energy consumption of the electric power system owing to the excellent material properties, which make it be the focus in the field of power electronics devices. However, the interface state density of SiC/SiO2 in the MOSFET SiC device is two orders higher than that of the Si/SiO2 interface, which leads to the low channel mobility, resulting in the degradation of the performance of the device. The existence of carbon element is the key factor of the high interface states. Research of the existing forms of carbon near the SiC/SiO2 interface in MOSFET SiC devices can better guide the oxidation process. In this paper, the basic reasons of high SiC/SiO2 interface states are analyzed. Then, the model and the theory study of the diffusion, fixed and the existence model of carbon element are summarized combined with the latest research progress. This research can provide basic theoretical guidance to the optimized oxidation process of SiC devices.
