The growth of high-quality crack-free GaN film on Si(111) substrates, using Al0.2Ga0.8N/AlN stacked interlayers, was studied. Compared with previously used single A1N interlayers, the AlGaN/AlN stacked interlayers could more effectively reduce the tensile stress within the GaN layer. Cross-sectional transmission electron microscopic imaging revealed the bending and annihilation of threading dislocations in the overgrown GaN film, leading to a decrease in threading dislocation density.

Effects of AlGaN/AlN Stacked Interlayers on GaN Growth on Si (111). H.Wang, L.Hu, Y.Wang, K.W.Ng, D.M.Deng, K.M.Lau: Chinese Physics Letters, 2010, 27[3], 038103