Hydrogenated amorphous silicon carbide thin films with high photo-sensitivity were fabricated by using layer-by-layer hydrogen annealing technique in conventional plasma enhanced chemical vapor deposition system. It was found that the photo-conductivity is increased from 1.9 x 10(-7) to 1.5 x 10(-6) S/cm after layer-by-layer hydrogen annealing. The photo-sensitivity can reach as high as 10(6) for sample with optical band gap of 2.11 eV. The influence of the hydrogen annealing time on film quality and optical properties were investigated. It was demonstrated that the layer-by-layer hydrogen annealing technique can improve the film quality, which can be attributed to both the hydrogen chemical annealing and hydrogen passivation effect. (c) 2013 Elsevier B.V. All rights reserved.