Growth of GaBN ternary solutions by organometallic vapor phase epitaxy

Abstract

Layers of Gal_ BxN with compositions from x = 0 to x = 0.07 were grown by organometallic vapor phase epitaxy on sapphire substrates using trimethylgallium, triethylboron (TEB) and NH 3 as precursors. Growth was done in the temperature range from 450 to 1000~ The presence of boron was detected by the shift in the (0002) peak position in x-ray diffraction, by x-ray photoelectron spectroscopy, secondary ion mass spectrometry measurements, and by the changes in the band gap as measured by optical transmission. It was found that for the studied range of compositions the band gap varied from 3.4 eV for x = 0 to 3.63 eV for x = 0.05. At certain TEB concentrations in the gas phase, the growth rate decreased abruptly, most likely because of a growth poisoning by the onset of growth of a very slow growing B-rich phase. The threshold TEB concentration for this growth poisoning decreased with increasing growth temperature; and at 1000~ less than 1% of B could be incorporated as a result. GaBN alloys with about 7% substitutional boron were also produced by implantation of 5 • 1018 cm -2 B ions at 60 keV into GaN, as evidenced by the shift of the band edge emission in cathodoluminescence spectra from 3.4 eV for GaN to 3.85 eV for GaBN.

MOVPE grown periodic AlN/BAlN heterostructure with high boron content

“…High boron containing layers growth by MOVPE has not been progressed a lot, which might be because the growth is normally performed at 1000 1C or above [2,4,10,11] in order to enhance B atoms diffusion, but at this high temperature the B-rich phase would poison the growth under high TEB/III ratio [12,13]. Low growth temperature can alleviate this problem and high boron incorporation can be achieved [13], but it does not facilitate growth of AlN for heterostructures or AlGaN MQWs.…”

Growth and Characterization of BxGa1−xN on 6H-SiC (0001) by Movpe

“…A.Y. Polyakov et al reported that the highest solubility of boron in GaN was 1% at 1000 °C by MOVPE [1]. Vezin et al produced a single phase of B x Ga 1-x N with x up to 4.56% by MBE [2].…”

Effect of boron incorporation on growth behavior of BGaN/GaN by MOVPE

“…It has been reported that at the typical growth temperature for B x Ga 1Àx N (about 1000 1C) the phase diagram contains regions of spinodal decomposition or phase separation in the interval of 0.028oxo0.995 [1,2]. The first experimental results reported by Polyakov et al [3] showed that the highest boron solubility in GaN grown at 1000 1C on sapphire was about 1%. Wei et al [4] reported single-phase BGaN alloy on AlN/SiC with the highest boron content of 1.5%.…”