Lateral epitaxial overgrowth of aluminum nitride on patterned silicon carbide substrates by hydride vapor phase epitaxy

摘要

This letter reports on the reduction of threading dislocation densities in AlN films via lateral epitaxial overgrowth by hydride vapor phase epitaxy. A variety of different stripe patterns were used to produce fully coalesced AlN films. Transmission electron microscopy (TEM) was used to assess the structural quality of these films. TEM determined that the dislocation density in the laterally grown wing regions was less than 8.3 x 10~6 cm~(-2) as compared to 1.8 x 10~9 cm~(-2) in the seed regions. Atomic force microscopy revealed that the films have a smooth surface morphology with a rms roughness of 0.71 nm over 10 x 10 μm~2 sampling areas.