CMOS image sensor and method of manufacturing thereof

A method of fabricating of a CMOS image sensor comprising:

• forming an epitaxial layer on a semiconductor layer;
• forming a device isolating layer for dividing the epitaxial layer into an active region and a device isolating region, the active region including a photo diode region and a transistor region;
• forming a trench hole in the device isolating layer and epitaxial layer between the photo diode region and the floating diffusion region;
• forming a gate electrode with side walls on a gate isolating layer in a drive transistor region on the epitaxial layer;
• forming a poly wiring in the trench hole which extends from the gate electrode to the photo diode region or the floating diffusion region;
• forming a gate spacer on both side walls of the gate electrode;
• and
• forming an impurity diffusion region by implanting ions into the epitaxial layer on the side of the gate spacers formed on the side walls of the gate electrode.

A CMOS image sensor comprising:

• an epitaxial layer formed on a semiconductor layer;
• a device isolating layer formed on the epitaxial layer which divides the epitaxial layer into an active region and a device isolating region, the active region including a photo diode region and a transistor region;
• a drive transistor including a gate electrode with side walls which is formed on the epitaxial layer, a gate oxide film formed on both walls of the gate electrode, and a gate spacer formed on the gate oxide film;
• a floating diffusion region formed on the epitaxial layer;
• a trench hole formed in the device isolating layer and the epitaxial layer between the photo diode region and the floating diffusion region, the trench hole partially overlapping the photo diode region or the floating diffusion region;
• a poly wiring formed in the trench hole which extends from the gate electrode of the drive transistor to the photo diode region or the floating diffusion region;
• and
• an impurity diffusion region formed by ion implanting a dopant in the epitaxial layer on the side of the gate spacers formed on the side walls of the gate electrode.