Influences of substrate temperature and Ar flow on the properties of RF sputtered Mo thin films

Abstract

We have reported the influences of substrate temperature and the rate of Argon (Ar) flow on the properties of Molybdenum (Mo) thin films. Different Ar flow rates (40, 60, 80, 100 SCCM) and different substrate temperatures (30, 100, 200, 300, 400 °C) were used for the substrate of Mo thin films by radio frequency (RF) magnetron sputtering technique. Structural properties studied by X-ray diffraction technique revealed cubic crystal structure with (110) prominent reflection. The electrical properties, viz. carrier concentration, resistivity and mobility were studied with the help of Hall measurement system. It has been revealed that substrate temperature and Ar flow significantly affect on the thickness, carrier concentration, resistivity and mobility of Mo layer. Upon increasing the substrate temperature, thickness increases, whereas thicker samples were grown at 80 and 100 SCCM for temperature 400 °C. The sample grown at 300 °C with 80 SCCM Ar flow measured high carrier concentration, whereas the resistivity and microstrain were found decreased systematically upon increasing the substrate temperature from room temperature 30 °C to 400 °C. Percentage reflectance examined with UV–Vis spectrometer revealed the sample grown with 80 SCCM at 400 °C measured higher reflectance. Highly dense, compact, uniform, and void-free growth of Mo layer were observed by AFM images. The effect of substrate temperature and Ar flow rate on surface morphology as well as RMS roughness is clearly observed.