Structural transition control of laterally overgrown c‐GaN and h‐GaN on stripe‐patterned GaAs (001) substrates by MOVPE

Abstract

Growth mechanisms and material quality of the laterally overgrown cubic-phase gallium nitride (c-GaN) and hexagonal-phase gallium nitride (h-GaN) on stripe-patterned GaAs (001) substrates were investigated using transmission electron microscopy (TEM). Investigational results show that h-GaN is only laterally overgrown along the (111)B facets of the c-GaN stripes with the growth direction of (0001) , which is six orders of magnitude smaller than that in the conventionally grown h-GaN films. On the other hand, the laterally overgrown c-GaN with lower planar defect (stacking faults and twins) density presents in the region just above the stripe windows for the [1 10]-stripe pattern. In addition, a large reduction of planar defect density was found in the laterally overgrown c-GaN regions for the [100] stripe direction. Also, a model is used to describe the cubic-to-hexagonal structural transition in lateral-overgrown GaN on patterned GaAs (001) substrates for the purpose of lower dislocation and lower planar defect densities in the laterally overgrown h-GaN and c-GaN, respectively.

Stacked structure of self‐organized cubic InN nano‐dots grown by molecular beam epitaxy

“…3, respectively. Both of the patterns represent the features of the zincblende structure [10,11]. Diffraction spots from c-GaN around the dot are slightly overlapped to the pattern of the c-InN dot in Fig.…”

“…Before deposition, a MgO substrate was thermally cleaned for 30 minutes at 1100 o C to obtain an atomically flat surface. Then a 15 nm-thick low temperature (LT) GaN buffer layer was grown on the substrate at 550 o C followed by the growth of a c-GaN underlayer with a thickness of 500 nm at 800 [10,11], and was kept throughout the following processes of the GaN cap growth and second InN deposition. Figure 2 shows AFM images taken after each fabrication step of the stacking structure.…”

Growth of cubic GaN on nano-patterned 3C-SiC/Si (0 0 1) substrates

“…The islands exhibit lateral facets that are inclined by $101 with respect to the growth direction and additional facets on the top which are inclined by $ 201 with respect to the sample template surface. Sanorpim et al [15] have observed similar faceting of cubic GaN in their studies of epitaxial lateral overgrowth of (0 0 1)-oriented stripe-patterned GaAs with cubic GaN by MOVPE. The mechanism of facet formation is not completely understood yet and will be a topic of further studies.…”

Metastable cubic InN layers on GaAs (001) substrates grown by MBE: Growth condition and crystal structure

“…The tilted angles between GaAs (002) plane and cubic (002) and hexagonal (10)(11) planes in the InN layers are 0° and ±7°, respectively. This demonstrates that the hexagonal-phase presented in the c-InN layers is mainly constructed on the cubic (111) surfaces and the crystal orientation relationship between hexagonal-phase inclusion and c-InN is hexagonal (0001)//cubic (111) [12,13].…”