Glide along non-basal slip planes in InGaN epilayers

摘要

We have observed a systematic nucleation of misfit dislocations at the InGaN/GaN heterointerface. This occurs when InGaN films are grown on an epitaxially laterally overgrown GaN substrate with a reduced dislocation density. The misfit dislocations are aligned along < 1100 > directions forming a symmetric hexagonal array. Potential wurtzite slip systems were analysed by extending the Matthews-Blakeslee model to include Peierls forces. Due to an inactive basal plane in the c-growth direction, non-basal slip is necessary for plastic relaxation. The active slip system was identified to be {1122} < 1123 >. The possibility of activation of other slip systems is also discussed.