US 8,044,444 B2 · CMOS image sensor and fabricating method thereof

Abstract

A fabricating method of a CMOS image sensor includes the steps of: forming a transfer gate on a semiconductor substrate where a device isolation layer is formed; forming a first n-type ion implantation region for a photodiode beneath a surface of the semiconductor substrate, the first n-type ion implantation region being aligned at one side of the transfer gate and having a first width and a first ion implantation depth; forming a second n-type ion implantation region aligned at one side of the transfer gate, the second n-type ion implantation region enclosing the first n-type ion implantation region and having a second width wider than the first width and a second ion implantation depth deeper than the first ion implantation depth and a second depth; forming a p-type ion implantation region between a surface of the semiconductor substrate and the first n-type ion implantation region, the p-type ion implantation region being aligned at one side of the transfer gate and partially overlapped with the first n-type ion implantation region; forming spacers on both sidewalls of the transfer gate; and forming a floating diffusion region at the other side of the transfer gate.

Claims23

Dependent claims

An image sensor, comprising:

a transfer gate formed on a surface of a semiconductor substrate;
a first n-type ion implantation region for a photodiode formed in the semiconductor substrate, aligned with one side of the transfer gate, and having a first width and a first ion implantation depth;
a second n-type ion implantation region aligned at the one side of the transfer gate, wherein the second n-type ion implantation region is configured to enclose the first n-type ion implantation region, to have a second width that is wider than the first width, and to have a second ion implantation depth that is deeper than the first ion implantation depth;
a p-type ion implantation region aligned at the one side of the transfer gate, wherein the p-type ion implantation region is configured to extend along the surface of the semiconductor substrate from the one side of the transfer gate, through the first n-type ion implantation region, and into the second n-type ion implantation region;
spacers formed on sidewalls of the transfer gate;
and
a floating diffusion region formed at another side of the transfer gate.

4 more elements

Dependencies are inferred from the claim text.

CMOS image sensor and fabricating method thereof

Life of this patent

CMOS image sensor and fabricating method thereof

Life of this patent

Abstract

Claims23