Effects of RF plasma parameters on the growth of InGaN/GaN heterostructures using plasma-assisted molecular beam epitaxy

The effects of rf plasma power on the structural/optical properties of GaN-based nitride epilayers grown by plasma-assisted molecular beam epitaxy have been investigated. Atomic force microscopy and high-resolution x-ray diffraction analyses revealed that the sharp interface of In _0.2Ga _0.8N/GaN heterostructures could be obtained by suppressing the surface roughening at high rf power. Photoluminescence data suggested that the formation of damaged subsurface due to energetic particles was alleviated in the InGaN growth in comparison with the GaN growth. In our experimental set-up, the rf power of 400 W appeared to properly suppress the 3D island formation without causing defects at the subsurface of In _0.2Ga _0.8N. The phenomena associated with the indium incorporation could be explained by an inequality with two kinetic processes of the surface diffusion and the plasma stimulated desorption.