Image sensor and method of fabricating the same

Abstract

A method of fabricating an image sensor, including: preparing a substrate including a pixel region and a logic region respectively having transistors, wherein the transistors comprise gates formed on a pixel region a logic region; forming a first interlayer dielectric film on a substrate to cover gates; first contact holes exposing a region of a substrate and a part of a gate on a pixel region by selectively etching a first interlayer dielectric film formed on a pixel region; forming first contacts by filing the first contact holes with a metal material; forming a second interlayer dielectric film on the entire surface of the first interlayer dielectric film; simultaneously forming second contact holes which may penetrate a second interlayer dielectric film on a pixel region to expose first contacts, and forming third contact holes which may penetrate a second interlayer dielectric film and the first interlayer dielectric film on the logic region to expose a part of a gate and a region of a substrate on the logic region; and forming second contacts by filling second contact holes and third contact holes with the metal material.

Description

[0001] This application claims priority from Korean Patent Application No. 10-2008-0104139 filed on October 23, 2008, the entire contents of which are hereby incorporated by reference. technical field [0002] The present invention relates to a semiconductor device, and more particularly, to a method of manufacturing a CMOS image sensor. Background technique [0003] Image sensors refer to semiconductor devices that convert optical images into electrical signals. Image sensors are classified into charge coupled device (Charge Coupled Device, CCD) image sensors and complementary metal oxide silicon (Complementary Metal-Oxide-Silicon, CMOS) image sensors. [0004] The image sensor includes a pixel area including a photodiode for detecting light and a logic area for processing the detected light into an electrical signal to obtain optical data. That is, the image sensor may refer to a device that receives light incident to a pixel region and captures an image using a photodiod...

AI Technical Summary

Problems solved by technology

When the etching depth is increased to ensure the etching margin to form a contact hole in the logic area, the etching depth of the contact hole in the pixel area increases, so that the photodiode, especially, the floating diffusion area is damaged, so Leakage current increases and dark current characteristics deteriorate

[0008] On the other hand, when reducing the etch allowance of the contact hole in the logic area to prevent damage to the pixel area due to etching, the contacts in the logic area composed of many circuits cannot be well formed.

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