Study of Mn Incorporation Into GaN:Mn Magnetic Semiconductor Thin Films Prepared by Plasma Assisted MOCVD

The effect of Mn incorporation into GaN:Mn thin films on their structural property, surface morphology and magnetic property are presented. The GaN:Mn thin films were grown by plasma-assisted metalorganic chemical vapor deposition (PA-MOCVD) using Trimethylgallium (TMGa), nitrogen (N₂) and cyclopentadienyl manganese tricarbonyl (CpMnTc) as a source of Ga, N and Mn, respectively. The grown films have Mn concentration as high as 6.6%. The maximum Mn concentration that still produces single phase GaN:Mn (0002) depends on growth temperature. The highest concentration of Mn atoms which are incorporated in the wurtzite structure substitutionally is 2.5%. Above this concentration, parts of Mn atoms are incorporated into GaN matrix intertitially. The surface roughness of the films determined from the AFM images show that the film with 6.4% of Mn has a better surface morphology than that of the film with 6.6 % of Mn. The results of magnetization measurements show hysteresis behavior at room temperature. The maximum of magnetic moment is achieved by the film with Mn concentration of 2.5 %