The impact of nanoporous SiN x interlayer growth position on high-quality GaN epitaxial films

Abstract

The impact of nanoporous SiN x interlayer growth position on high-quality GaN epitaxial film was elucidated from the behavior of dislocations. The best quality GaN film was achieved when a nanoporous SiN x interlayer was grown on a rough layer, with the high-resolution X-ray diffraction rocking curve full width at half maximum for ( 1102 ) reflection decreasing to 223 arcs, and the total dislocation density reduced to less than 1.0×10 8 cm −2. GaN films were grown on sapphire substrates by metal organic chemical vapor deposition. The quality of these films was investigated with high-resolution X-ray diffraction, atomic force microscopy, and cross-sectional transmission electron microscopy. A preference for the formation of half-loops to reduce threading dislocations was observed when an SiN x interlayer was grown on a rough layer. A growth mechanism is proposed to explain this preference.growth models, defects, metal-organic chemical vapor deposition, GaN, SiN x

The substantial dislocation reduction by preferentially passivating etched defect pits in GaN epitaxial growth

“…Dislocations are known to terminate at a free surface or incorporate with other dislocations that have partly opposite Burgers vector. 16) According to that, two ways are concluded to eliminate dislocations. One way is to introduce some masks to prevent dislocations from propagating up.…”