A novel low-temperature crystallization method is proposed; the excimer laser annealing (ELA) of amorphous silicon (a-Si) with a hydrogen-modulation-doped layer (ELHMD). The effects of hydrogen on low-energy crystallization by conventional ELA and ELHMD were investigated. As the hydrogen concentration increases, the crystallinity of the polycrystalline silicon (poly-Si) prepared at a low energy density improves. It is considered that the nucleation is enhanced by the desorption energy of hydrogen from the Si-H2 bond during the Si melting. In addition, the film exfoliation by H2 burst can be suppressed using HMD a-Si film.