On cracking in thick GaN layers grown on sapphire substrates

doi:10.18720/MPM.4412020_1

On cracking in thick GaN layers grown on sapphire substrates

Authors:

A.E. Romanov M.G. Mynbaeva A.A. Sitnikova A.N. Smirnov K.D. Mynbaev H. Lipsanen A.V. Kremleva D.A. Bauman V.E. Bougrov

Abstract:

Self-organization mechanisms promoting elimination of cracks in thick GaN layers grown on sapphire substrates are considered on the basis of the experimental results on the fabrication of the layers by Hydride Vapor-Phase Epitaxy on MOCVD-grown GaN/Al₂O₃ templates. The obtained data support the supposition on the closure of tensile stress-related cracks via diffusion processes and demonstrate the strong contribution of bulk diffusion in addition to surface diffusion discussed earlier.