AVS 49th International Symposium
    Electronic Materials and Devices Wednesday Sessions
       Session EL+SC-WeP

Paper EL+SC-WeP6
Growth of Gallium Nitride on Silicon Substrate by MOCVD Using Multiple Buffer Layers

Wednesday, November 6, 2002, 11:00 am, Room Exhibit Hall B2

Session: Poster Session
Presenter: D.A. Gulino, Ohio University
Authors: M.A. Al-Tamimi, Ohio University
D.A. Gulino, Ohio University
Correspondent: Click to Email
An attempt has been made to improve the crystalline quality of MOCVD-grown gallium nitride on silicon (111) substrate by the insertion of a second aluminum nitride buffer layer. The conventional method for growing GaN on heterosubstrates has been to first grow a thin, low-temperature layer of typically aluminum or gallium nitride to act as a compliant, or "buffer," layer to reduce the degree of crystalline defects and threading dislocations in the subsequently-grown GaN epilayer. In the work reported here, a second, low-temperature AlN buffer layer was grown on top of the first GaN epilayer, and this was followed by a second GaN epilayer. We have found improvement in the crystalline quality of the second GaN epilayer as measured by x-ray diffraction rocking curves. We also experimented with ramping the temperature during growth of both the first and second AlN buffer layers, and we discovered that the best quality GaN film obtained in this work occurred when the first buffer layer was grown as the temperature was ramped from 800 to 1060°C and the second buffer layer grown at a fixed temperature of 800°C.