We fabricated Mn-irradiated InAs quantum dot (QD) structures at 500 degrees C. In the case of Mn irradiation on InAs QDs without As, the terraces were observed around dots by an atomic force microscope (AFM). It is believed that Mn atoms adhere to InAs QDs and MnAs is formed. Furthermore, we measured micro-photoluminescence from such Mn-irradiated InAs QD samples under magnetic fields. Clear Zeeman splitting was observed at 2.9 K. The estimated absolute values of the exciton g factor were 2.4-3.8. (c) 2006 Elsevier B.V. All rights reserved.