STRESS ENGINEERING TO REDUCE DARK CURRENT OF CMOS IMAGE SENSORS

摘要

PURPOSE: A stress engineering capable of reducing a dark current of a CMOS image sensor is provided to reduce a white cell count by depositing a stress layer as a part of free-metal dielectric layer. CONSTITUTION: A photo diode(105) is adjacent to an STI(Shallow Trench Isolation) structure. A transistor controls the operation of an active pixel cell(100). A stress layer(401) is deposited on the device of the active pixel cell. The stress layer has the second stress corresponding to the first stress applied to the substrate. The second stress reduces a dark current and a white cell count generated by the first stress.