NITRIDATION OF GAAS(111) BY DIMETHYL-HYDRAZINE (DMHY) WITH AS-4 MOLECULAR-BEAM

Wide temperature range nitridation of GaAs(1 1 1) substrates by DMHy w ith As-4 molecular beam have been investigated to convert GaAs to GaN. The nitridation rate strongly depends on the pressures of the DMHy an d the As4 beams and the substrate temperature. The nitridation even at higher temperature range for the GaAs substrates is possible by using simultaneous supply of the DMHy and the As-4 beams. The RHEED from th e nitrided layers of the GaAs(1 1 1) B substrates shows a strong zincb lende pattern mixed with a weak wurtzite one in the investigated tempe rature range, in contrast to the case of the nitridation for the GaAs( 1 1 1) A substrates in which the RHEED shows a wurtzite one only. The results indicate that the nitridation process can be controlled by the simultaneous supply of the DMHy and the As-4 beams. (C) 1998 Elsevier Science B.V. All rights reserved.