Method for fabricating vertical CMOS image sensor
AssigneeDongbu Electronics Co., Ltd.
InventorSang Lee
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Abstract
A method of fabricating a vertical CMOS image sensor is disclosed, to improve the integration with the decrease in size of pixel by minimizing the lateral diffusion, in which phosphorous and arsenic ions are implanted while controlling the dose and energy, the method including forming a first photodiode in a semiconductor substrate; forming a first epitaxial layer on the semiconductor substrate; forming a first plug by sequentially implanting first and second ions in the first epitaxial layer; forming a second photodiode in the first epitaxial layer; forming a second epitaxial layer in the first epitaxial layer; forming an isolation area in the second epitaxial layer; and forming a third photodiode and a second plug in the second epitaxial layer.
Claims32
A method for fabricating a vertical CMOS image sensor comprising:
- forming a first photodiode in a semiconductor substrate;
- forming a first epitaxial layer on the semiconductor substrate including the first photodiode;
- forming a first plug by sequentially implanting first and second ions in the first epitaxial layer;
- forming a second photodiode in the first epitaxial layer;
- forming a second epitaxial layer on the first epitaxial layer including the second photodiode;
- forming an isolation area in the second epitaxial layer;
- and
- forming a third photodiode and a second plug in the second epitaxial layer.
A method for fabricating a vertical CMOS image sensor comprising:
- forming a first plug in a first epitaxial layer on a semiconductor substrate having a first photodiode therein, by implanting a first ion having a relatively low molecular weight at a low dose and at a high energy, and implanting a second ion having a relatively high molecular weight at a higher dose and at a low energy, in the first epitaxial layer;
- and
- forming a second photodiode in the first epitaxial layer.
A vertical CMOS image sensor comprising:
- a semiconductor substrate having a first photodiode therein;
- a first epitaxial layer thereon, having a first plug therein, the first plug comprising (i) a relatively low dose of a first ion having a relatively low molecular weight and a relatively large depth, and (ii) a relatively high dose of a second ion having a relatively high molecular weight and a relatively shallow depth;
- and
- a second photodiode in the first epitaxial layer.
Dependencies are inferred from the claim text.