CMOS image sensor and method for fabricating the same
A CMOS image sensor and a method for fabricating the same are disclosed, in which an impurity ion area is formed in a semiconductor substrate to form a transfer path for optical charges. Dead zone and dark current characteristics are thereby simultaneously improved. The CMOS image sensor includes a first conductive type semiconductor substrate, a device isolation film, a gate electrode, a second conductive type first impurity ion area and a first conductive type first impurity ion area formed with a deposition structure in the semiconductor substrate below the gate electrode, a second conductive type second impurity ion area, and a first conductive type second impurity ion area formed on a surface of the second conductive type second impurity ion area.
1 . A CMOS image sensor comprising:
a first conductive type semiconductor substrate defined by an active area and a device isolation area;
a device isolation film formed in the first conductive type semiconductor substrate corresponding to the device isolation area;
a gate electrode formed on the first conductive type semiconductor substrate corresponding to a transistor area of the active area;
a second conductive type first impurity ion area and a first conductive type first impurity ion area formed with a deposition structure in the semiconductor substrate below the gate electrode;
a second conductive type second impurity ion area formed in the semiconductor substrate of a photodiode area; and
a first conductive type second impurity ion area formed on a surface of the second conductive type second impurity ion area.
2 . The CMOS image sensor of claim 1 , further comprising a source and drain area formed in the semiconductor substrate at sides of the gate electrode, and a first conductive type third impurity ion area formed in the semiconductor substrate of the source and drain area.
3 . The CMOS image sensor of claim 2 , wherein the first conductive type third impurity ion area is formed by implanting first conductive type impurity ions in a tilt ion implantation manner.
4 . The CMOS image sensor of claim 2 , wherein the first conductive type third impurity ion area is extended to a portion below the gate electrode by control of an ion implantation angle.
5 . The CMOS image sensor of claim 2 , wherein the first conductive type impurity ions for the first conductive type third impurity ion area are any one of B ions, BF 2 ions, Ga ions, and In ions.
6 . A method for fabricating a CMOS image sensor comprising:
forming a first conductive type first impurity ion area on a surface of an active area of a first conductive type semiconductor substrate defined by the active area and a device isolation area;
forming a second conductive type first impurity ion area below the first conductive type first impurity ion area corresponding to a transistor area of the active area;
forming a gate electrode on the semiconductor substrate corresponding to the transistor area;
forming a second conductive type second impurity ion area in the semiconductor substrate corresponding to a photodiode area of the active area; and
forming a first conductive type second impurity ion area on a surface of the second conductive type second impurity ion area.
7 . The method of claim 6 , further comprising:
forming a first conductive type third impurity ion area in the semiconductor substrate at sides of the gate electrode; and
forming a source and drain area in the semiconductor substrate of the source and drain area.
8 . The method of claim 7 , wherein the first conductive type third impurity ion area is formed by implanting first conductive type impurity ions in a tilt ion implantation manner.
9 . The method of claim 7 , wherein the first conductive type third impurity ion area is extended to a portion below the gate electrode by control of an ion implantation angle.
10 . The method of claim 7 , wherein the first conductive type impurity ions for the first conductive type third impurity ion area are any one of B ions, BF 2 ions, Ga ions, and In ions.