Patent ID: 7405437
Filing Date: 2008-07-29
Classification: H01L

Abstract:
1. A CMOS image sensor comprising: a first conductive type semiconductor substrate having a photodiode area and a transistor area; a trench formed in the semiconductor substrate corresponding to a transfer transistor of the transistor area; a gate electrode of the transfer transistor formed in the trench; a plurality of gate electrodes formed on the semiconductor substrate of the transistor area, excluding the transistor area of the transfer transistor; source and drain impurity ion areas formed in the semiconductor substrate between the respective gate electrodes; an impurity ion implantation area for controlling a threshold voltage formed on the semiconductor substrate only below the gate electrode; a second conductive type impurity ion area formed in the semiconductor substrate of the photodiode area; and a first conductive type impurity ion area formed on a surface of the second conductive type impurity ion area, wherein a top surface of the gate electrode of the transistor including a reset transistor and excluding the transfer transistor is higher than a top surface of the gate electrode of the transfer transistor.