Surface modifications and optical properties of blue InGaN single quantum well by in-situ thermal treatments

We investigated the surface modifications and optical properties of blue InGaN single quantum well (SQW) using the in-situ annealing process with different two temperatures. The surface of blue InGaN SQW was significantly modified from spiral surface to step-like surface structure as well as the degradation of InGaN PL emission efficiency after in-situ annealing process at a 1030 C for 3 min in the metalorganic chemical vapor deposition (MOCVD) system. However, the surface of InGaN SQW was modified from spiral surface to spinodal pattern surface structure after in-situ annealing process at the InGaN growth temperature of 750 C. These results implied that the surface atoms of InGaN could significantly rearranged by the thermal treatments at the high temperatures just after the InGaN growth. This surface reconstruction process can be caused by the desorption, the evaporation, and the surface migration of surface adatoms to reduce the thermodynamical instability. Moreover, it is possible to be happened the spinodal related phase separation of InGaN SQW under the in-situ annealing process with the InGaN growth temperature. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)