Method of fabricating backside illuminated image sensor
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShih-Chi Fu, Gwo-Yuh Shiau, Liang-Lung Yao, Yuan-Chih Hsieh, Feng-Jia Shiu
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Abstract
A method for fabricating a backside illuminated image sensor is provided. An exemplary method can include providing a substrate with a front surface and a back surface; forming a first alignment mark for global alignment on the front surface of the substrate; forming a second alignment mark for fine alignment in a clear-out region on the front surface of the substrate; aligning the substrate from the back surface using the first alignment mark; and removing a portion of the back surface of the substrate at the clear-out region for locating the second alignment mark.
Claims20
A method for fabricating an electronic device, comprising:
- providing a substrate with a front surface and a back surface;
- forming a first alignment mark for global alignment on the front surface of the substrate;
- forming a second alignment mark for fine alignment in a clear-out region on the front surface of the substrate;
- and
- removing a portion of the back surface of the substrate at the clear-out region tor locating the second alignment mark, wherein the removing includes performing registration from the back surface using the first alignment mark as a reference.
A method for fabricating a back-side illuminated image sensor, comprising:
- providing a semiconductor substrate having a front surface, back surface, active region, and clear-out region;
- forming a first alignment mark on the front surface of the substrate;
- forming a second alignment mark on the front surface in the clear-out region;
- selectively etching a portion of the substrate from the back surface within the clear-out region by performing registration from the back surface and using the first alignment mark as a reference;
- and
- processing the active region of the substrate from the back surface by performing registration from the back surface and using the second alignment mark as a reference.
Dependencies are inferred from the claim text.