Plasma emission diagnostics for the optimization of deposition parameters in RF magnetron sputtering of GaP film

GaP thick films were prepared on ZnS substrates by RF magnetron sputtering starting from a GaP target in an Ar atmosphere. Plasma emission diagnostics was employed to investigate the glow discharge during the deposition process. Only the emission lines of Ar atom appear and effects of the deposition parameters on the intensities of the emission lines were studied systematically. The deposition parameters were optimized through increasing the RF power and decreasing the working gas pressure of Ar simultaneously, with the intensity of the emission lines kept constant. And thus, stoichiometric GaP thick films with high IR transmission performance were deposited at an elevated deposition rate.