High-resolution transmission electron microscopy images of (a) , (b) , and (c) films on 4H-SiC.
(a) Radial scan along the specular direction of a film on 4H-SiC (0001). The peak is evident and no other diffraction peaks related to the film are observed. The SiC (0004) peak is not complete because the scan was not performed over the peak maximum to avoid saturating the detector. With filters in place, the SiC (0004) peak was separately scanned to obtain the resolution limit of the system. (b) The reflection in log scale, illustrating the interference fringes. (c) Rocking curve of the reflection. The peak is resolution-limited and the line shape is due to the detector slit size. (d) Crystallite dimension normal to the interface as a function of film thickness. The dashed line indicates the thickness of a crystallite spanning the film thickness.
(a) In-plane phi scans illustrating an epitaxial alignment of the plane with the 4H-SiC plane. (b) Selected area electron diffraction pattern of a film on 4H-SiC. (c) Selected area electron diffraction pattern showing twinning around the  axis. (d) HRTEM image of a film which clearly illustrates a grain boundary in the film due to twinning.
(a) Phi scan of the reflection of a film compared to the background phi scan which shows no measurable offset. (b) Radial scan of the peak at in which no peak is observed, confirming the lack of misoriented grains. (c) Phi scan of the reflection of a film compared to the background phi scan which shows a large offset. (d) Radial scan of the peak at , confirming the presence of misoriented grains.
Percentage of grains oriented in-plane with the substrate, , as a function of film thickness.
Strain observed in thin films on SiC (0001) relative to the JCPDS value, as a function of the film thickness.
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