Three-dimensional imaging and tilt-angle analysis of dislocations in 4H-SiC by two-photon-excited band-edge photoluminescence

We demonstrate the three-dimensional imaging of threading screw dislocations (TSDs), threading edge dislocations (TEDs), and basal plane dislocations (BPDs) in 4H-SiC using two-photon-excited band-edge photoluminescence. Three-dimensional images of TSDs, TEDs, and BPDs are obtained successfully as dark contrasts on a bright background of band-edge emission. Dislocation images extending ~200 µm from the surface are demonstrated. The tilt angles of TSDs and TEDs in 4H-SiC epilayers are also measured, and the mechanisms governing the line directions of TEDs and TSDs are discussed.