In this paper we discuss the laser annealing crystallization of hydrogenated a-Si film deposited at 250degC by means of PECVD technique. Abrupt out-diffusion of hydrogen damages the deposited layers during single shot high energy density laser annealing. On the contrary, a multisteps laser annealing approach, from low to high energy density, allows us to achieve good poly-Si film, without any H-related defect.