Atomic scale characterization of SiO2/4H-SiC interfaces in MOSFETs devices

Abstract

Abstract. The breakthrough of 4H-SiC MOSFETs is stemmed mainly due to the mobility degradation in their channel in spite of the good physical intrinsic material properties. Here, two different n-channel 4H-SiC MOSFETs are characterized in order to analyze the elemental composition at the SiC/SiO 2 interface and its relationship to their electrical properties.Elemental distribution analyses performed by EELS reveal the existence of a transition layer between the SiC and the SiO 2 regions of the same width for both MOSFETs despite a factor of nearly two between their electron mobility. Additional 3D compositional mapping by atom probe tomography corroborates these results, particularly the absence of an anomalous carbon distribution around the SiC/SiO 2 interface.

X-ray Absorption Fine Structural Study of Atomic Structures and Chemical States of Dopants in 4H-SiC(0001)

“…Atom probe tomography shows the three-dimensional dopant distributions in the film. 12,13 However, chemical information about a dopant cannot be detected. dopants in real space.…”

“…In the case of X-ray diffraction, the atomic structures of dopants cannot be obtained due to the lack of periodicity with such dopants. Atom probe tomography shows the three-dimensional dopant distributions in the film. , However, chemical information about a dopant cannot be detected. High-resolution scanning transmission electron microscopy can clarify the atomic arrangement of the dopants in real space.…”