Sapphire substrates have been widely adopted to grow high quality GaN epilayer despite the large differences of lattice constant and thermal expansion coefficient between them. So, GaN or AlN buffer layer on the sapphire was indispensably introduced before the GaN epilayer growth. Moreover, a pretreatment process prior to the buffer growth has been known to play a critical role in improving the GaN overgrown layer. Nitridation is a general and simple pretreatment at high temperature in N2 or NH3 ambience. A post-annealing process was employed to decrease lattice strain through thermal treatment, and the electrical properties such as Hall mobility and carrier concentration were improved by this increase of crystallinity. These results showed that improvement of the GaN epilayer can be achieved by combination of N+-ion-implantation pretreatment of sapphire substrate and a suitable post-annealing process.
|Journal||Journal of the Korean Physical Society|
|Publication status||Published - 2003 Feb|
|Event||Proceedings of The 11th Seoul International Symposium on the Physics of Semiconductors and Apllications - 2002 - Cheju Island, Korea, Republic of|
Duration: 2002 Aug 20 → 2002 Aug 23
- N-ion implantation
ASJC Scopus subject areas
- Physics and Astronomy(all)