The soft magnetic properties of FeAlN films have been shown to be strongly dependent on the temperature of the substrate during deposition. Films of FeAlN were sputtered deposited onto Alumina/Titanium Carbide (ALTIC) ceramic substrates at substrate temperatures between 20 and 200 degrees C. In the range of 150 to 200 degrees C, the films display a well oriented easy axis with coercivities less than 1.5 Oe, and a hard axis coercivity of less than 1 Oe. Deposition at temperatures below 150 degrees C resulted in high coercivities and no in-plane anisotropy. This behavior is explained in terms of the temperature dependence of the formation of the gamma'-Fe4N phase (identified by x-ray diffraction), which is necessary for the soft magnetic properties. A discussion of heating transients due to substrate thermal mass is also included.