Measurement and control of deposition temperature of Gd-Co rf sputtered films

A vacuum evaporated Chromel-Constantan Thin Film Thermocouple (TPTC) is developed and used to measure the deposition temperature of rf sputtered amorphous gadolinium-cobalt films. Deposition temperature can be varied with the type and the amount of thermal backing which affixes the substrates to the substrate holder. By controlling the temperature of cooling water running through the substrate holder control of the deposition temperature can be achieved to some degree. Results indicate that under normal deposition conditions the temperature on the substrate surface is around 1 °C. Results also indicate that gallium has better heat conduction and less temperature scatter than silicone grease when the same deposition parameters are maintained. Magnetic properties such as saturation magnetization, stripe period, anisotropy constant, exchange stiffness, and wall energy are investigated near the thermocouple junction where the deposition temperature is definitely known. A few Gd-Co-Mo films are also prepared during this research work and their magnetic properties are illustrated