The difference in the operational properties between r.f. conventional diode (CD) and planar magnetron (PM) sputterings has been studied. The PM mode of operation is obtained by setting a circular permanent magnet on a copper plate back of the target electrode in the CD apparatus. The direct-current self-bias potential generated at the cathode for the PM mode of operation is found to be about an order smaller than that for the CD mode. InSb epitaxial films have been grown on (0001) sapphire substrates by the CD and PM modes of operation The deposition I-ate for the PM mode of operation is about an order larger than that for the CD mode. Spectroscopic-ellipsometry and atomic force microscopy data are presented to show that the PM-deposited InSb film has a relatively gentle, terraced surface while the CD-deposited film has a roughened surface with the emergence of deep hollows. It is also found that the Hall mobility in the PM-deposited film is considerably higher than that in the CD-deposited one.