GSrowth of GaN layers on GaAs and GaP (111) and (001) substrates by molecular beam epitaxy

摘要

Films of GaN have been grown using a modified MBE technique in which the active ntrogen is supplied from an RF poasma source. Wurtzite films grown on (001) oriented GaA substrates show highly defective, ordered olycrystalline growth with a solumnar structure, the (001) planes of the layers being parallel to the (001) planes of the gaAs substrate. Films grown using a coincident As flux, however, have a single crystal zinc-blende growth mode. They have better structral and optical properities. To improve the properties of the wutzite films we have studied the growth of such films on (111) oriented gaAs and GaP substrates. The improved structural properties of such films, assessed using X-ray and TEM method, correlate with better low-temperature PL.