METHOD FOR MANUFACTURING CMOS IMAGE SENSOR

摘要

PURPOSE: A method for manufacturing a CMOS image sensor is provided to reduce dark current by thickening a residual spacer layer on the surface of a photodiode. CONSTITUTION: A lightly doped epitaxial layer(21) is formed on a heavily doped substrate(20). A field oxide layer(22) is formed on the epitaxial layer to define an active and field region. A gate electrode(23) is formed on the active region. A doping region(24) for a photodiode is formed in the epitaxial layer to align the gate electrode. By depositing an insulating layer and blanket etching, a spacer(25a) is formed at both sidewalls of the gate electrode and a residual spacer layer(25b) is formed on the active region. The thickness of the residual spacer layer is 100-500Å.