H-2 additional effect for crystallization of SnO2 films prepared by the hot-wire CVD method was investigated. The crystallization of SnO2 films starts at 170 degrees C. The selectivity enhancement of the solar cell substrate will contribute to reduce the cost of silicon thin film solar cells. The atomic hydrogen assisted nano-crystallization exists for the depositions of SnO2 films by the hot-wire CVD method. Furthermore, the addition of H-2 gas improved the electrical conductivity up to 5.3 x 10(0) S/cm. However, these effects are limited in the deposition condition of a small amount of hydrogen. Addition of much higher hydrogen concentration starts an etching effect of oxygen atoms. (C) 2011 Elsevier B.V. All rights reserved.