CMOS image sensor and method for fabricating the same
OwnerKeun Liminventor
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Abstract
A CMOS image sensor and a method for fabricating the same forms a trench-shaped transfer gate that serves to better transfer electrons generated by light incident on photodiodes, thus obtaining improved transfer characteristics. The CMOS image sensor includes a semiconductor substrate having at least one active region defined by a shallow trench isolation region; a light-receiving region formed in a surface of the semiconductor substrate; and a transfer gate buried in the semiconductor substrate between the light-receiving region and the at least one active region, wherein the transfer gate has a trench shape of a predetermined depth.
Claims14
A CMOS image sensor comprising:
- a semiconductor substrate having at least one active region defined by a shallow trench isolation region;
- a light-receiving region formed in a surface of said semiconductor substrate;
- and
- a trench shaped transfer gate in said semiconductor substrate between said light-receiving region and the at least one active region.
A method for fabricating a CMOS image sensor comprising:
- forming a trench in a semiconductor substrate;
- filling the trench with polysilicon;
- forming a transfer gate by patterning the polysilicon to remain in the trench;
- forming, using a photo-masking process, a lightly doped region as a photodiode on one side of the transfer gate by implanting N−-type ions into the semiconductor substrate;
- implanting P−-type ions in a surface region of the photodiode;
- and
- forming an active region as a heavily doped region by implanting N+-type ions into the semiconductor substrate on the other side of the transfer gate.
A method for fabricating a CMOS image sensor, comprising:
- defining at least one active region by a shallow trench isolation region in a semiconductor substrate;
- forming a light-receiving region in a surface of the semiconductor substrate;
- and
- forming a transfer gate in the semiconductor substrate between the light-receiving region and the at least one active region, wherein said transfer gate has a trench shape of a predetermined depth.
Dependencies are inferred from the claim text.