Effects of Reactor Pressure on Epitaxial Lateral Overgrowth of GaN via Low-Pressure Metalorganic Vapor Phase Epitaxy

The effects of reactor pressure on epitaxial lateral overgrowth (ELO) via low-pressure metalorganic vapor phase epitaxy (MOVPE) have been studied in relation to growth temperature. For the ELO GaN on SiO2 stripes along the <1100> direction of the underlying GaN, on decreasing the reactor pressures from 500 to 40 Torr or increasing the growth temperatures from 950 to 1050°C, the (0001) surfaces become broad and the side walls changed from inclined {1122} surfaces to vertical {1120} surfaces. For the ELO GaN on the stripes along the <1120> direction, the shapes with {1101} facets are independent of the reactor pressure and growth temperature. The ELO of GaN is dominated by the diffusion-limited process.