SURFACE-ROUGHNESS AND MAGNETIC-PROPERTIES OF IN-SITU HEATED AND POSTANNEALED THIN-FILMS OF PERPENDICULAR BARIUM FERRITE

The surface roughness and magnetic properties of thin films of hexagon al barium ferrite (BaFe) deposited on SiO2/Si and Si substrates by fac ing target sputtering were studied using in situ heating during deposi tion and postannealing after deposition. The perpendicular coercivity of the BaFe films varied between 775 and 1430 Oe with substrate temper ature for both in situ heated (560-620-degrees-C) and postannealed (80 0-1200-degrees-C) films. The effect of temperature on the surface roug hness of BaFe/Si was greater than that of BaFe/SiO2/Si. The results of this study indicate that the mean surface roughness (R(a) = 11.4-27 m n) of BaFe films on Si substrates was greater than the roughness (R(a) = 3.9-17 nm) of BaFe films on amorphous SiO2/Si substrates. This incr ease of surface roughness with increasing substrate temperature is due to the evolution of grain boundaries and step formation during deposi tion and annealing.