The Influence of Mn/Ga Solution Mole Fraction on the Solid Composition and Microstructure of GaN:Mn Thin Film Deposited on Silicon Substrate by Spin Coating Technique

Abstract

The influence of Mn/Ga solution on the characteristics of solid composition and microstructure of GaN:Mn thin film was studied. GaN:Mn thin films were deposited on Si (111) substrate by the Chemical Solution Deposition (CSD) method using the spin coating technique. Variations of the Mn/Ga mole fraction were 4%, 6%, 8%, and 10% respectively. The GaN:Mn thin films were then heated at a temperature of 900°C for 2 hours in an N2environment with a constant flow rate of 120 sccm. Atomic composition, crystal structure, and surface morphology of GaN:Mn thin films were characterized using X-Ray Diffraction (XRD), Energy Dispersive of X-ray (EDX), and Scanning Electron Microscope (SEM). EDX results showed that the larger the Mn/Ga mole fraction solution, the higher the Mn At percentage is. The correlation of At Mn percentage and Mn/Ga solution mole fraction is represented by the formula y = 0.023x3- 0.352x2- 1.742x -2.81. All of the GaN:Mn thin films still have nitrogen vacancy, carbon impurity and maintain the wurtzite polycrystalline structure. Lattice parametera, which is in the range of 3.2077Å – 3.2621Å, and lattice parameterc,which is in the range of 5.1094Å – 5.3038Å, depend on Mn atomic percentage of the film. The Root Mean Square (RMS) of GaN:Mn thin film surface roughness is in the range of 15.3nm – 29.90nm. The grain size for the 6% Mn/Ga mole fraction thin film is homogeneous.