Image sensor and fabricating method of image sensor

A fabricating method of an image sensor, comprising:

• forming a first type epitaxial layer on a first type substrate;
• forming a first type well region within the first type epitaxial layer with a vertical distance to a surface of the first type epitaxial layer;
• forming a gate region of a source follower transistor on an oxide formed on the surface of the first type epitaxial layer and above the first type well region;
• forming a photodiode region within the first type epitaxial layer with a first horizontal distance to the first type well region, and a second horizontal distance to the gate region of the source follower transistor;
• and
• forming a first type implant isolation region within the first type epitaxial layer and between the first type well region and the photodiode region;
• wherein the first horizontal distance is longer than the second horizontal distance, and there is a distance between the first type implant isolation region and the first type well region as an anti-blooming path.