The effect of defects and their passivation on the density of states of the 4H-silicon-carbide/silicon-dioxide interface

Abstract

A methodology to identify and quantify mobility-reducing defects in 4H-silicon carbide power metal-oxidesemiconductor field-effect transistors

An amorphous SiO2/4H-SiC(0001) interface: Band offsets and accurate charge transition levels of typical defects

“…The εðÀ1=À2Þ level of the carbon dimer is located 0.1 eV below the conduction band of 4H-SiC. It means that the carbon dimer in the SiC substrate is a possible cause of the mobility degradation in SiC-based MOS devices, in agreement with the previous study by Pantelides et al [37][38][39]. For N Si in SiC, the εðÀ1=À2Þ level lies above the CBM of 4H-SiC and the other three levels εð0=À1Þ, εð1=0Þ, and εð2=1Þ occur at 2.40 eV, 1.11 eV, and 0.55 eV with respect to the VBM of 4H-SiC, respectively.…”

Structural and electronic properties of the transition layer at the SiO2/4H-SiC interface

“…These carbon clusters are located in the SiC side of the SiO 2 /SiC interface, which is consistent with the previous theoretical investigations. 27,30 This may explain the experimentally observed carbon excess at the interface. 14,15 To elucidate the chemical bonding and charge transfer between carbon clusters and the surrounding atoms, we depict the three-dimensional charge-density difference with respect to carbon clusters (see Fig.…”

“…Such defective structures have not yet been considered in the previous theoretical studies. 20,21,24,27,30 Apart from that, our non-abrupt interface model also include excited configurations, such as fivefold-coordinated Si atoms (SiO 5 ) and threefold-coordinated O atoms. The SiO 5 center does not mean the O enrichment of the interface because a fivefold-coordinated silicon event is accompanied by the generation of threefold-coordinated oxygen atoms.…”

“…Unfortunately, due to the limitation of formed SiO 2 film to the diffusion of carbon oxide, a small portion of carbon atoms still remain in the oxide and at the interface. [24][25][26][27][28][29][30] The residual carbon atoms may contribute to the formation of carbon clusters, as observed by atomic force microscopy (AFM) 13 and combined transmission electron microscopy (TEM)/electron energy loss spectroscopy (EELS). 14,15 Much theoretical work has been performed to understand the atomic-scale nature of carbon-related defects at the SiO 2 /SiC interface.…”

SiC/SiO2 Interface Characteristics in N-based 4H-SiC MOS Capacitor Fabricated with PECVD and NO Annealing Processes

“…탄소 결합체로 인한 계면 포획 레벨은 주로 4H-SiC 전도대역 바로 아래의 금지대역에 형성된다 [13] . 탄소 결합체 외에도 SiO2의 비등방성 성장에 의 한 전이층 두께의 증가 및 Si 원자의 소실로 인한 추 가적인 포획 전하의 증가 등이 SiC/SiO2의 계면 특성 에 영향을 주는 부차적인 요인이다 [14] . 사용할 경우, 계면 포획 농도의 값이 실제보다 적게 나오는 문제가 있다 [15] .…”