Impurity incorporation in semipolar (1-1 0 1) GaN grown on an Si substrate

Abstract

Carbon doping was investigated in (1-1 0 1) GaN, where the topmost surface is terminated by nitrogen. Intentional doping was performed supplying C 2 H 2 as the source precursor during the MOVPE growth under N 2 ambient. The sample showing p-type conduction exhibited a strong but broad peak at 361 nm in a low-temperature cathode luminescence spectrum. FTIR analyses were performed on these samples and a new absorption peak at 945 cm −1 was found along with an AlN-A 1 (LO) phonon mode at 888 cm −1 . SIMS analyses showed unintentionally highly doped Al in the sample. The 945 cm −1 peak was assigned to a local vibration mode related to an Al-C bond.

Influence of TMAl preflow on AlN epitaxy on sapphire

“…23) or a kind of complex, such as the Al-C-O complex. 24,25 To further verify the existence of graphitic C on the sapphire surface after the preflow process, Raman measurements were carried out on the TMAl-only samples. Raman measurements were carried out on the TMAl-only samples in a Horiba Jobin Yvon confocal Micro-Raman HR 800 system, using a 473 nm laser excitation source.…”