SiドープGaN中ドーパント活性サイトの化学状態・原子構造

抄録

X-ray absorption near-edge structure (XANES) and photoelectron spectroscopy were used to investigate the active and inactive dopant sites in Si-doped GaN. Si-doped GaN formed two dopant states, which were attributed to Si₃N₄ and SiN_x. From the Si K-edge XANES, the Si₃N₄ state did not exhibit electronic states in the GaN bandgap, indicating inactive dopant sites in GaN, whereas the SiN_x state exhibited bandgap states. Thus, the SiN_x state should act as an active dopant site in Si-doped GaN. The simulation of XANES spectra well reproduced the electronic state in the GaN-bandgap when the Ga atom is replaced by the Si atom, suggesting that the active dopant site may be the Si-substituted Ga sites.