This article reports the formation of epitaxial Si film that were formed by directly depositing a Sb-doped n-type epilayer on a p-type substrate by using a DC bais RF magnetron sputter system at a low temperature of 400 degreesC and a conventional vacuum of 5 x 10(-7) Torr. In addition, the plasma parameters were quantitatively investigated to examine the deposition condition. The electron density (n(c)) of about 10(17) m(-3) Was obtained at the plasma region under the conditions where gas pressure was 3 mTorr, the power of the RF source was 350 W and the 2 electron temperature (T-c) and ion saturation current (I-0) were in the range of 3-4 eV and 1-1.5 mA/cm(2), respectively. The p-n junction diode fabricated by the Si epitaxy shows, under optimum conditions, a reverse current density (RCD) as low as 9.5 x 10(-6) mA/cm(2) at a reverse bias voltage of 5 V and an ideality factor of 1.05. The reverse current density has a good correlation with the crystallinity of the deposited films, which, in turn, depends on deposition ps pressures and substrate biases. (C) 2004 Elsevier B.V. All rights reserved.