We have studied the substrate temperature dependence of the series resistance of Al/SnO2/P-Si (1 1 1) Schottky diodes prepared by spray deposition method. Tin oxide films have been deposited on various silicon substrate temperatures (300, 350, 400 and 450 degreesC) using a spray deposition process. The parameter series resistance R-s, the ideality factor n and the apparent barrier height Phi(BO) are determined by performing different plots from the forward current-voltage (I-V) characteristics. We have found that the barrier height increased as the ideality factor decreased with an increase of the substrate temperature. The R, estimated from Cheung's method and Lien's method was increased by increasing the substrate temperature. We have found the suitable series resistance response to the lowest value of ideality factor for the diode prepared at 400 degreesC (SD3 sample). (C) 2004 Elsevier B.V. All rights reserved.