Effect of sapphire nitridation and group-III source flow rate ratio on In-incorporation into InGaN grown by metalorganic vapor phase epitaxy.

In-composition of N-polar InGaN films on the sapphire substrate with the surface nitridation was investigated. By varying the ratio of the group-III source flow rate from 0.7 to 0.95, the In-composition and the surface morphologies of InGaN films were changed. The In-composition of N-polar InGaN films was affected by the strain relaxation and the surface morphologies.