Comparison of the temperature dependence of the properties of ion beam and magnetron sputtered Fe films on (100) GaAs

The effects of substrate temperature on the crystallographic, electrical, and mechanical properties of ion beam (IBS) and magnetron sputtered (MS) Fe films on (100) GaAs were studied and compared. Films were deposited at substrate temperatures ranging from 100 to 500 °C. Given the large differences between the two deposition techniques, the film properties were remarkably similar. A higher deposition rate was achieved for magnetron sputtering, and the deposition rate increased with increasing temperature for both techniques. For both deposition techniques, as the substrate temperature was increased the films changed from random or (110) oriented to a preferred (200) orientation, with IBS films having a higher degree of preferred orientation. The full-width at half-maximum of the (200) rocking curves are comparable for both techniques and varied from 0.5° to 0.9°. Both techniques show an initial decrease in resistivity with increasing temperature, reaching a minimum resistivity approaching that of bulk Fe at about 200 °C. With further increases in temperature, the resistivity increases. Resistivity of IBS films was lower than that of MS films. The stress of MS films was tensile (0.5–1.5 GPa) at all deposition temperatures while the stress for IBS films was compressive (−1 GPa) at low temperatures and became tensile (0.5 GPa) at high temperatures.