n型4H-SiC材料中位错的电学特性研究

研究位错的电学特性对于研究器件可靠性具有重要意义.文章利用拉曼散射技术在室温条件下研究了n型4H-SiC材料中位错电学特性.结果表明:螺型位错(TSD)、刃型位错(TED)的电子浓度均高于无位错区,且TSD电子浓度高于TED.结合位错结构分析认为:TED中心的半原子面存在不饱和Si键,该键通过吸附电子使其饱和并达到稳定状态,因此TED中心俘获了比无位错区更多的电子;TSD结构中,位错区域原子间的拉应力导致该区域Si原子电负性增高,因而俘获电子形成比无位错区高的电子分布.

Study on Dislocation Electrical Properties in N-type 4H-SiC Material

The electrical properties of dislocations in n-type 4H-SiC material were studied by Raman scattering techniques at room temperature. The results show that the electron concentration of both the threading screw dislocation (TSD) and the threading edge dislocations (TED) are higher than that of the dislocation-free zone, and the electron concentration TSD is higher than that of TED. Based on the dislocation theory, the relationship between the electron distribution and dislocation structure was discussed. It is suggested that the unsaturated Si bond in TED and increasing electronegativity of Si atom in TSD make dislocations electron concentration are higher than that in the dislocation-free zone.