Methods of forming an image sensor

A method of fabricating an image sensor, the method comprising:

• etching a first surface of a substrate to form a trench defining a unit pixel region, the substrate further comprising a second surface opposite the first surface;
• performing an atomic layer deposition process to form a passivation layer conformally covering a surface of the trench, the passivation layer being doped with impurity ions during the atomic layer deposition process;
• forming a protection layer on the passivation layer;
• forming a first capping pattern on the protection layer to partially fill the trench;
• forming a second capping pattern on the first capping pattern to fill a remaining space of the trench;
• forming a photoelectric conversion part in the unit pixel region of the substrate;
• and
• forming a floating diffusion region in the unit pixel region of the substrate, the floating diffusion region being adjacent the first surface of the substrate and spaced apart from the photoelectric conversion part.

A method of forming an image sensor, the method comprising:

• forming a trench in a substrate to define a unit pixel region of the substrate;
• forming an in-situ-doped passivation layer on an exposed surface of the trench;
• forming a capping pattern on the in-situ-doped passivation layer, in the trench;
• forming a photoelectric conversion region in the unit pixel region;
• and
• forming a floating diffusion region in the unit pixel region.