Growth of GaN Nano-Column on Si (111) Substrate Using Au+Ga Alloy Seeding by Pulsed Flow Method Using MOCVD
Vertical GaN nano-columns arrays were grown on Au-coated silicon (111) substrate by Au+Ga alloy seeding method and pulsed flow of Gallium and ammonia using metalorganic chemical vapor deposition (MOCVD). A gold thin film was deposited on Si using an ion coating system. The Au coated Si substrate was annealed at 800 oC under hydrogen ambient for 5 min. The pre-deposition of gallium and nitrogen was performed for 60 sec to form Au+Ga and nitrogen solid solution, which acts as the initial nucleation islands. Then Gallium and ammonia were let in pulse method. Scanning electron microscopy (SEM) image reveals a vertical growth and cylindrical in shape GaN nano-column. From the sharp PL peak intensity it is clearly seen that the dislocation density is reduced considerably and the optical quality of the nano-column is improved.
S. J. CHUA, J. H. TENG, O. WADA, R. DE LA RUE and X. H. TANG
J. C. Song et al., "Growth of GaN Nano-Column on Si (111) Substrate Using Au+Ga Alloy Seeding by Pulsed Flow Method Using MOCVD", Advanced Materials Research, Vol. 31, pp. 108-110, 2008