Method for fabricating CMOS image sensor

Abstract

A method for fabricating a CMOS image sensor is disclosed, to minimize the leakage current and to improve the yield, which includes the steps of preparing a semiconductor substrate including a peripheral circuit and a pixel array, wherein the pixel array is comprised of a photodiode and a readout circuit; defining an active area and a field area in the semiconductor substrate; forming a field oxide layer in the field area of the semiconductor substrate; forming gate electrodes in the peripheral circuit and the readout circuit of the pixel array; forming a photodiode in a photodiode portion of the pixel array; forming source and drain junctions at both sides of the gate electrode in the semiconductor substrate of the active area; forming a salicide prevention layer in the semiconductor substrate of the pixel array; and forming salicide layers in the surface of the gate electrode and the source and drain junctions in the peripheral circuit by using the salicide prevention layer as a mask.

Description

[0001] This application claims the priority of Korean Patent Application No. P2004-52007 filed on July 5, 2004, the entire content of which is incorporated herein by reference. Technical field [0002] The present invention relates to a method for manufacturing an image sensor, and more specifically, to a method for manufacturing a CMOS image sensor to reduce leakage current. Background technique [0003] Generally, an image sensor is a semiconductor device for converting optical images into electrical signals. Image sensors can be roughly classified into charge coupled devices (CCD for short) and complementary metal oxide semiconductor (CMOS) image sensors. [0004] In the case of a CCD, corresponding metal silicon oxide MOS capacitors are arranged adjacent to each other, in which charge carriers are stored and transferred to the capacitor. At the same time, CMOS image sensors adopt CMOS technology that uses control circuits and signal processing circuits as peripheral circuits. ...

AI Technical Summary

Problems solved by technology

[0027] Leakage currents have adverse effects on CMOS image sensors

More specifically, if the leakage current increases, the yield will decrease to 0%

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