The 1/f noise has been investigated for the first time at 300 and 77 K in high-quality 4H-SiC Schottky diodes. It is shown that, at 77 K, the dependence of the spectral noise density on current, S-I(I), differs fundamentally between the cases of the current flowing through the main part of the diode with a comparatively high barrier and the current flowing through the nano-sized patches with a comparatively low barrier. (C) 2014 Elsevier Ltd. All rights reserved.