Image sensor and method of manufacturing the same

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

• forming a first dopant region having a second conductivity type in a semiconductor substrate,
• wherein the semiconductor substrate comprises a first surface and a second surface opposite to the first surface, and the semiconductor substrate has a first conductivity type different from the second conductivity type;
• forming a pixel isolation structure defining a plurality of pixel regions in the semiconductor substrate;
• forming a vertical trench by patterning the first surface of the semiconductor substrate in each of the pixel regions;
• forming a mask pattern exposing each of the pixel regions on the first surface of the semiconductor substrate, wherein the mask pattern comprises a residual mask pattern filling at least a portion of the vertical trench;
• forming a second dopant region by ion-implanting dopants having the second conductivity type into the semiconductor substrate by using the mask pattern as an ion-implantation mask, wherein the second dopant region is adjacent to the vertical trench;
• and
• forming a transfer gate electrode in the vertical trench, wherein a gate insulating layer is interposed between the transfer gate electrode and an inner surface of the vertical trench.