Growth of crack-free semi-polar (1-101) GaN on a 7°-off (001) Si substrate by metal-organic chemical vapor deposition

摘要

This paper reports a novel selective growth method for growing crack-free semi-polar (1-101) GaN on 7°-off (001) Si substrates by adding SiO_2 stripes in perpendicular to the V-grooves on Si. This method can effectively reduce the thermal stress between GaN and Si substrate so that crack-free (1-101) GaN films as thick as 1 um is achieved after coalescence even without an A1N interlayer. Cathodoluminescence measurements show the presence of low dislocation density areas, which can be attributed to the bending of dislocations toward to the [1-100] and [11-20] directions during the facet growth.