A method of fabricating an image sensor is provided. The method includes comprises forming a deep trench in a semiconductor substrate, performing a first plasma doping process to form a first impurity region a portion of in the semiconductor substrate adjacent to inner sidewalls and a bottom surface of the deep trench, the first impurity region being doped with first impurities of a first conductivity type, and performing an annealing process to diffuse the first impurities from the first impurity region into the semiconductor substrate to form a photoelectric conversion part.