| AFM image and RHEED pattern after one-hour nitridation at 100 °C [(a) and (b)]. |
| AFM image and RHEED pattern after one-hour nitridation at 200 °C [(a) and (b)]. |
| AFM image and RHEED pattern after one-hour nitridation at 700 °C [(a) and (b)]. |
| Surface roughness after one-hour nitridation and GaN bulk growth as a function of temperature. |
| FWHM of the X-ray rocking curves for the symmetric and asymmetric reflections of 0.9µm-GaN bulk. |
| AFM images after the 0.9µm-GaN bulk growth at (a) 100°C, (b) 200°C for one-hour nitridation. |
| AFM images after the 0.9µm-GaN bulk growth at (a) 300°C, (b) 400°C for one-hour nitridation. |
| AFM image after the 0.9µm-GaN bulk growth at 700°C for one-hour nitridation. |