The propagation characteristics of dislocations were investigated in InGaN/GaN multi-quantum-well structures grown by metalorganic chemical vapor deposition. Threading dislocations with Burgers vector of b = <¯1¯1•0>, emerged from the GaN buffer region, change their glide plane from normal to parallel to the growth plane when they meet InGaN wells. Dislocations gliding on the growth planes were pinned by quantum dots leaving two possible ways of propagation, changing their glide plane back to normal to the growth plane, {10•0}, or extending loop shape pinned both ends by the quantum dots. Indium-rich quantum dots were formed on the InGaN quantum-well layers with size of 30nm in diameter. It was estimated that the critical size of quantum dots to pin the dislocations was 30nm.

Dislocation Behavior in InGaN/GaN Multi-Quantum-Well Structure Grown by Metalorganic Chemical Vapor Deposition. Y.W.Kim, E.K.Suh, H.J.Lee: Applied Physics Letters, 2002, 80[21], 3949-51