CONSTRUCTION METHODS FOR BACKSIDE ILLUMINATED IMAGE SENSORS
First Claim
1. Method of manufacturing a thin semiconductor device, the method comprising the steps of:
- forming a semiconductor wafer having a substrate layer and an electronics layer, wherein the substrate layer is thicker than the electronics layer, the substrate layer extends to a bottom surface of the semiconductor wafer and the electronics layer includes a plurality of electrical contacts that extend to a top surface of the semiconductor wafer;
forming, in a handle wafer separate from the semiconductor wafer, a plurality of via holes, each of the via holes extending from a top surface of the handle wafer partially through the handle wafer toward a bottom surface of the handle wafer and corresponding in position on the handle wafer to a respective one of the plurality of electrical contacts on the semiconductor wafer;
attaching the top surface of the semiconductor wafer to the top surface of the handle wafer such that the via holes in the handle wafer are aligned with the respective electrical contacts on the semiconductor wafer;
removing the substrate layer from the semiconductor wafer;
removing at least a portion of the handle wafer from the bottom surface of the handle wafer to expose the plurality of via holes; and
filling each of the exposed via holes with a conductive material to form a conductive channel from the respective electrical contact in the at least one via hole.
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Accused Products
Abstract
A method of constructing a backside illuminated image sensor is described. The method includes the steps of forming a semiconductor wafer, forming at least electrical contacts in the semiconductor wafer, forming, in a handle wafer separate from the semiconductor wafer, a plurality of via holes, attaching the semiconductor wafer to the handle wafer such that the via holes in the handle wafer are aligned with the respective electrical contacts on the semiconductor wafer, removing the substrate layer from the semiconductor wafer, removing at least a portion of the handle wafer to expose the plurality of via holes, filling each of the exposed via holes with a conductive material and applying a solder material to each of the exposed via holes such that the conductive material in each of the via holes is electrically connected to the solder material.
166 Citations
25 Claims
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1. Method of manufacturing a thin semiconductor device, the method comprising the steps of:
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forming a semiconductor wafer having a substrate layer and an electronics layer, wherein the substrate layer is thicker than the electronics layer, the substrate layer extends to a bottom surface of the semiconductor wafer and the electronics layer includes a plurality of electrical contacts that extend to a top surface of the semiconductor wafer; forming, in a handle wafer separate from the semiconductor wafer, a plurality of via holes, each of the via holes extending from a top surface of the handle wafer partially through the handle wafer toward a bottom surface of the handle wafer and corresponding in position on the handle wafer to a respective one of the plurality of electrical contacts on the semiconductor wafer; attaching the top surface of the semiconductor wafer to the top surface of the handle wafer such that the via holes in the handle wafer are aligned with the respective electrical contacts on the semiconductor wafer; removing the substrate layer from the semiconductor wafer; removing at least a portion of the handle wafer from the bottom surface of the handle wafer to expose the plurality of via holes; and filling each of the exposed via holes with a conductive material to form a conductive channel from the respective electrical contact in the at least one via hole. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of manufacturing a thin semiconductor device, the method comprising the steps of:
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forming a semiconductor wafer having a substrate layer and an electronics layer, wherein;
the substrate layer is thicker than the electronics layer, the substrate layer extends to a bottom surface of the semiconductor wafer and the electronics layer extends to a top surface of the semiconductor wafer;forming a handle wafer separate from the semiconductor wafer; attaching the top surface of the semiconductor wafer to a top surface of the handle wafer; removing the substrate layer from the semiconductor wafer; forming a glass cover layer over the bottom surface of the semiconductor wafer; flipping the semiconductor wafer so that a bottom surface of the handle wafer is exposed for processing; and using the glass cover layer to provide mechanical support for the semiconductor wafer, removing the handle wafer from the semiconductor wafer. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A back illuminated imager comprising:
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a semiconductor wafer including a plurality of image sensing elements configured to receive light through a back side of the wafer; a plurality of lenses disposed above the back side of the wafer such that an air gap is formed between the plurality of lenses and the back side of the wafer; a cover glass attached to the back side of the wafer such that the cover glass is disposed above the plurality of lenses and the air gap; and a plurality of electrical contacts formed on a front side of the wafer. - View Dependent Claims (21, 22, 23)
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24. A back illuminated imager comprising:
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a semiconductor wafer including a plurality of image sensing elements configured to receive light through a back side of the wafer; a plurality of electrical contacts formed on the front side of the wafer; a handle wafer permanently bonded to the semiconductor wafer, the handle wafer having formed through it a plurality of vias, each via corresponding to a respective one of the plurality of electrical contacts and filled with a conductive material. - View Dependent Claims (25)
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Specification