Atomic configurations in AP-MOVPE grown lattice-mismatched InGaAsN films unravelled by X-ray photoelectron spectroscopy combined with bulk and surface characterization techniques

Abstract

This work presents the results of X-ray photoelectron spectroscopy studies on the bonding N configuration in InGaAsN epilayers grown by atmospheric pressure metal organic vapour phase epitaxy. Growth temperature has been tuned in order to obtain both, relaxed and strained layers. The studies were concentrated on analysing the influence of the growth temperature, post growth thermal annealing process and surface quality on the formation of Ga-N and InN bonds as well as N-related defects. The contamination of InGaAsN films by growth precursor residues and oxides has also been addressed. The growth temperature stands out as a decisive factor boosting InN bonds formation, while the thermal annealing seems to affect the N-related defects density in the layers.

Impact of gallium concentration in the gas phase on composition of InGaAsN alloys grown by AP-MOVPE correlated with their structural and optical properties

“…Therefore, the growth of dilute nitrides has been scarcely studied in an atmospheric pressure metal organic vapour phase epitaxy (AP-MOVPE) [10,11], which is a challenge for growers, but allows the reduction of the production cost of MJSCs based on these metastable compounds. Our earlier experiments [12][13][14][15] indicated a high In/N composition ratio (10 ÷ 30) in InGaAsN alloys grown by AP-MOVPE. Consequently it was impossible to obtain thick (~ 1 µm) layers with good material quality.…”

“…In order to achieve the required In/N composition ratio of ~ 3, the gas phase molar ratio of gallium to the total amount of group-III precursors Ga/(Ga + In) was only increased from 0.821 to 0.970 by changing the flow rate of TMGa V TMGa = 13.8, 29.5, 43.2, 59, 78.6, 98.3 µmol/min (samples NI129, NI135, NI136, NI130, NI131, NI132) at the constant flow rate of TMIn V TMIn = 3 µmol/min. We expected both a decrease of indium incorporation and an increase of the growth rate, which could result in increasing the nitrogen content in the growing InGaAsN alloys [12,16].…”

“…The formation of these islands can be connected with the precursor debris [12] and/or the disrupted step edges [27,28]. In the case of the compressively strained InGaAsN layer (sample NI129, Fig.…”