Abstract: GaN films with and without a Al/AIN buffer layers are grown on Si(111) substrate via metalorganic chemical vapor deposition (MOCVD)，respectively.The films are characterized by optical microscopy( OM)，X-ray diffraction rocking curve (XRDRC)，and Raman scattering(RS). OM shows that the GaN film inserting with 8Al/AlN buffer layers has less cracks than film without any δAl/AIN buffer layers.XRDRC demonstrates good quality of the GaN film with δAl/AIN buffer layers and Raman scattering analyses reveal that it is an effective way to overcome the difficulties of growing GaN on Si(111)sub. strate by inserting δAl/AIN buffer layers.

Key words: GaN, MOCVD, AlN, buffer layers