We report the reduction of noise voltage power spectral density (PSD) of amorphous Si(1-x)Ge(x)O(y) microbolometers by forming gas passivation. The microbolometers fabricated from Si(1-x)Ge(x)O(y) were passivated in a rapid thermal annealing chamber in the presence of forming gas at 250 degrees C with different intervals of time starting from 0.5 h to 8 h. The noise voltage PSD was measured at different bias currents before passivation and after different interval of passivation time. It was found that the noise voltage PSD of the bolometers decreased as the passivation time increased. The 1/f-noise coefficient (K(f)) was decreased from 7.54 x 10(-7) to 2.21 x 10(-10) after 8 h of forming gas passivation performed at 250 degrees C. (c) 2008 Elsevier B.V. All rights reserved.