This work describes the effect of nitrogen doping to eutectic Sb-Te phase-change materials in order to enhance the speed of the amorphous-to- crystalline phase transformation. When nitrogen at a sputtering gas flow ratio of N2 / Ar=3% was doped in the eutectic Ge-In-Sb-Te recording layer, the data transfer rate was increased up to 1.6 times. When thin GeNx nucleation promotion layers were further added in below and above the recording layer, an overall enhancement up to 3.3 times in data transfer rate was achieved. The nitrogen contents corresponding to the N2 /Ar flow ratios (N2 Ar=0%-10%) were calibrated by electron spectroscopy for chemical analysis. Transmission electron microscopy revealed that nitrogen doping was able to promote the phase transformation by generating numerous nucleation sites uniformly distributed in the recording layer and hence increased the recrystallization speed.