Three-dimensional imaging of extended defects in 4H-SiC by optical second-harmonic generation and two-photon-excited photoluminescence

Abstract

We demonstrate three-dimensional (3D) defect imaging in 4H-SiC epilayers by optical second-harmonic generation (SHG) and two-photon-excited photoluminescence (2PPL). The SHG method provides clear 3D images of 3C inclusions because 3C-SiC is SHG-active, but not 4H-SiC host crystal in c-axis incidence. The 2PPL method also yields 3D images of 3C inclusions, 8H stacking faults, and single Shockley stacking faults in the epilayers. The spectra obtained by the SHG and 2PPL imaging methods are investigated, and the emission mechanisms discussed.