Image acquisition device
AssigneeSTMicroelectronics (Crolles 2) SAS
InventorsLaurent GAY, Magali GREGOIRE, Bilel SAIDI, Sylvain JOBLOT, Benjamin VIANNE
Life of this patent
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Abstract
An image sensor includes photodetection pixels formed inside and on top of a semiconductor substrate. An interconnection network coats a surface of the semiconductor substrate. The interconnection network includes a level of conductive vias in contact, by their lower surface, with the photodetection pixels. The conductive vias are made of doped polysilicon and have a heavier doping on their lower surface side than on their upper surface side.
Claims19
An image sensor, comprising:
- photodetection pixels formed inside and on top of a semiconductor substrate;
- and
- an interconnection network over a surface of the semiconductor substrate, the interconnection network comprising conductive vias, wherein lower surfaces of the conductive vias are in electrical contact with the photodetection pixels;
- wherein each conductive via is made of doped polysilicon;
- and
- wherein the doped polysilicon has a heavier doping at the lower surface of the conductive via than at an upper surface of the conductive via.
An image acquisition device, comprising:
- a first image sensor comprising:
- first photodetection pixels formed inside and on top of a first semiconductor substrate;
- and
- an interconnection network over a surface of the first semiconductor substrate, the interconnection network comprising conductive vias, wherein lower surfaces of the conductive vias are in electrical contact with the first photodetection pixels;
- wherein each conductive via is made of doped polysilicon;
- and
- wherein the doped polysilicon has a heavier doping at the lower surface of the conductive via than at an upper surface of the conductive via;
- and
- a second image sensor comprising second photodetection pixels formed inside and on top of a second semiconductor substrate;
- wherein the first image sensor and the second image sensor are stacked.
A method of manufacturing an image sensor, comprising:
- forming photodetection pixels inside and on top of a semiconductor substrate;
- and
- forming a level of an interconnection network including conductive vias;
- wherein lower surfaces of the conductive vias are in contact with the photodetection pixels;
- wherein each conductive via is made of doped polysilicon;
- and
- wherein the doped polysilicon has a heavier doping at the lower surface of the conductive via than at an upper surface of the conductive via.
Dependencies are inferred from the claim text.