EFFECTS OF SUBSTRATE-TEMPERATURE AND ANGULAR POSITION ON THE PROPERTIES OF ION-BEAM SPUTTER-DEPOSITED FE FILMS ON (100) GAAS SUBSTRATES

The effects of substrate temperature and position on the properties of Fe films deposited onto (100) GaAs substrates by ion beam sputtering were studied. Films were deposited on substrates at angular positions from -20-degrees to 66-degrees, with respect to the target surface normal, at temperatures from 100 to 500-degrees-C. The deposition rate was higher in the forward scattered direction but decreased for angles greater than 45-degrees. The macroscopic film stress was compressive at low temperatures but underwent a compressive to tensile transition between 300 and 500-degrees-C. Furthermore, the stress varied with substrate position. The stress predicted from thermal expansion mismatch is tensile. Both the low temperature compressive stress and the variation of stress with position are qualitatively accounted for by an energetic bombardment or ''atomic peening'' process. For optimum deposition conditions, the films are highly (200) oriented, with rocking curves as narrow as 0.5-degrees. The resistivity of the films approaches that of bulk Fe, and the variations of resistivity with deposition conditions appear to be associated with the crystallographic perfection of the films.