WAFER LEVEL PROCESSING FOR BACKSIDE ILLUMINATED IMAGE SENSORS
First Claim
1. A wafer level processing method for forming a plurality of image sensors each having a pixel array configured for backside illumination, the image sensors being formed utilizing an image sensor wafer, the image sensor wafer comprising a substrate, an oxide layer formed over the substrate, a sensor layer formed over the oxide layer, and one or more dielectric layers formed over the sensor layer, the sensor layer comprising photosensitive elements of the pixel arrays, the method comprising the steps of:
- attaching a temporary carrier wafer to a frontside surface of said at least one dielectric layer;
removing the substrate to expose a backside surface of the oxide layer;
forming color filter arrays on the backside surface of the oxide layer;
attaching a transparent cover sheet comprising transparent covers overlying respective ones of the color filter arrays;
removing the temporary carrier wafer;
forming openings in said at least one dielectric layer to expose respective bond pad conductors;
forming redistribution metal conductors in electrical contact with the respective bond pad conductors through the respective openings;
forming a redistribution passivation layer over the redistribution metal conductors;
forming openings in the redistribution passivation layer to expose portions of respective ones of the redistribution metal conductors; and
forming contact metallizations in electrical contact with the respective redistribution metal conductors in respective ones of the openings in the redistribution passivation layer.
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Accused Products
Abstract
A backside illuminated image sensor comprises a sensor layer having a plurality of photosensitive elements of a pixel array, an oxide layer adjacent a backside surface of the sensor layer, and at least one dielectric layer adjacent a frontside surface of the sensor layer. A color filter array is formed on a backside surface of the oxide layer, and a transparent cover is attached to the backside surface of the oxide layer overlying the color filter array. Redistribution metal conductors are in electrical contact with respective bond pad conductors through respective openings in the dielectric layer. A redistribution passivation layer is formed over the redistribution metal conductors, and contact metallizations are in electrical contact with respective ones of the respective redistribution metal conductors through respective openings in the redistribution passivation layer. The image sensor may be implemented in a digital camera or other type of digital imaging device.
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Citations
13 Claims
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1. A wafer level processing method for forming a plurality of image sensors each having a pixel array configured for backside illumination, the image sensors being formed utilizing an image sensor wafer, the image sensor wafer comprising a substrate, an oxide layer formed over the substrate, a sensor layer formed over the oxide layer, and one or more dielectric layers formed over the sensor layer, the sensor layer comprising photosensitive elements of the pixel arrays, the method comprising the steps of:
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attaching a temporary carrier wafer to a frontside surface of said at least one dielectric layer; removing the substrate to expose a backside surface of the oxide layer; forming color filter arrays on the backside surface of the oxide layer; attaching a transparent cover sheet comprising transparent covers overlying respective ones of the color filter arrays; removing the temporary carrier wafer; forming openings in said at least one dielectric layer to expose respective bond pad conductors; forming redistribution metal conductors in electrical contact with the respective bond pad conductors through the respective openings; forming a redistribution passivation layer over the redistribution metal conductors; forming openings in the redistribution passivation layer to expose portions of respective ones of the redistribution metal conductors; and forming contact metallizations in electrical contact with the respective redistribution metal conductors in respective ones of the openings in the redistribution passivation layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A digital imaging device comprising:
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an image sensor having a pixel array configured for backside illumination; and one or more processing elements configured to process outputs of the image sensor to generate a digital image; wherein said image sensor comprises; a sensor layer comprising a plurality of photosensitive elements of the pixel array; an oxide layer adjacent a backside surface of the sensor layer; at least one dielectric layer adjacent a frontside surface of the sensor layer; a color filter array formed on a backside surface of the oxide layer; a transparent cover attached to the backside surface of the oxide layer and overlying the color filter array; redistribution metal conductors in electrical contact with respective bond pad conductors through respective openings in said at least one dielectric layer; a redistribution passivation layer formed over the redistribution metal conductors; and contact metallizations in electrical contact with respective ones of the respective redistribution metal conductors through respective openings in the redistribution passivation layer. - View Dependent Claims (13)
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Specification