Effect of growth conditions on GaN grown by lateral epitaxial overgrowth

We investigated the effects of growth parameters on GaN structures grown by lateral epitaxial overgrowth (LEO) on SiN_x/GaN/Al₂O₃ wafers by low-pressure metalorganic chemical vapor deposition. The ratio of the lateral to the vertical growth rates (γ) increased with increasing growth temperature and V/III ratio. The crystallographic tilting of the LEO grown GaN strongly depended on the growth conditions. At low growth temperature and high reactor pressure, γ was less than unity, and the LEO grown GaN had a trapezoidal shape. Under these regrowth conditions, the tilt angle of LEO grown GaN decreased.