Improved characteristics and issues of m-plane InGaN films grown on low defect density m-plane freestanding GaN substrates by metalorganic vapor phase epitaxy

Abstract

Improved quantum efficiency and short radiative lifetime were demonstrated for the near-band-edge emission of nearly stacking-fault-free, 200–250-nm-thick, m-plane pseudomorphic InxGa1−xN (0<x≤0.14) films grown by metalorganic vapor phase epitaxy on the low threading dislocation density (<5×106 cm−2) freestanding (FS) GaN substrates. Values of full width at half maximum of x-ray ω-rocking curves of the InxGa1−xN films remain unchanged as the substrate values being 80 and 60 arcsec for the (101¯0) diffraction with ⟨0001⟩ and ⟨112¯0⟩ azimuths, respectively, and 80 arcsec for the (101¯2) diffraction. As the surface flatness was improved, the incorporation efficiency of In was lower than the cases for c-plane growth and m-plane growth on a defective GaN substrate, according to nonidentical surface kinetics and absence of inclined/tilted planes, respectively.

Implementation of Spatio-Time-Resolved Cathodoluminescence Spectroscopy for Studying Local Carrier Dynamics in a Low Dislocation Density m-Plane In0.05Ga0.95N Epilayer Grown on a Freestanding GaN Substrate

“…20) The InGaN epilayer was confirmed by the X-ray reciprocal space mapping method to grow coherently 15) on the base GaN. As expected from the crystallographic orientation, so-called Vdefects often observed in c-plane InGaN films 21) were absent.…”

“…A 70-nm-thick m-plane In 0:05 Ga 0:95 N epilayer 15) was grown by MOVPE on a 325-m-thick m-plane FS-GaN, 10) after growing an 1.5-m-thick GaN underlayer. 20) The InGaN epilayer was confirmed by the X-ray reciprocal space mapping method to grow coherently 15) on the base GaN.…”

“…Accordingly, there remain concerns if such structural imperfections would cause inhomogeneous incorporation of In during the InGaN growths, [12][13][14] because the In-incorporation efficiency differs depending on the crystallographic orientation of the growth front. As a matter of fact, the full-width at half-maximum (FWHM) values for the near-band-edge (NBE) photoluminescence (PL) peak of the m-plane In x Ga 1Àx N epilayers 5,15) grown by metalorganic vapor phase epitaxy (MOVPE) on FS-GaN were larger than those for c-plane In x Ga 1Àx N epilayers 16) of the same InN mole fractions (x). In order to assess local carrier dynamics in a semiconductor, Merano et al 17) have recently developed a picosecond spatio-time-resolved cathodoluminescence (STRCL) technique to probe InGaAs/AlGaAs pyramidal nanostructures.…”

“…In this article, the results of STRCL measurements on the very low TD and BSF density m-plane In 0:05 Ga 0:95 N epilayer 15) grown on the high-quality FS-GaN substrate 10) are displayed. Local variation of the cathodoluminescence (CL) peak energy is attributed to a considerable difference in the local InN mole fraction caused by the residual structural imperfections.…”

Implementation of Spatio-Time-Resolved Cathodoluminescence Spectroscopy for Studying Local Carrier Dynamics in a Low Dislocation Densitym-Plane In0.05Ga0.95N Epilayer Grown on a Freestanding GaN Substrate

“…A 70-nm-thick m-plane In 0:05 Ga 0:95 N epilayer 15) was grown by MOVPE on a 325-m-thick m-plane FS-GaN, 10) after growing an 1.5-m-thick GaN underlayer. 20) The InGaN epilayer was confirmed by the X-ray reciprocal space mapping method to grow coherently 15) on the base GaN.…”