Dual Facing BSI Image Sensors with Wafer Level Stacking

摘要

A device includes two BSI image sensor elements and a third element. The third element is bonded in between the two BSI image sensor elements using element level stacking methods. Each of the BSI image sensor elements includes a substrate and a metal stack disposed over a first side of the substrate. The substrate of the BSI image sensor element includes a photodiode region for accumulating an image charge in response to radiation incident upon a second side of the substrate. The third element also includes a substrate and a metal stack disposed over a first side of the substrate. The metal stacks of the two BSI image sensor elements and the third element are electrically coupled.

主权项

1. A device comprising:
a first BSI image sensor, wherein the first BSI image sensor includes a first substrate and a first metal stack disposed over a first side of the first substrate, the first substrate includes a photodiode region between the first side and a second side of the first substrate, the first metal stack is operatively coupled to the first substrate, and the first metal stack includes a first material layer at a first side of the first metal stack; a second BSI image sensor, wherein the second BSI image sensor includes a second substrate and a second metal stack disposed over a first side of the second substrate, the second substrate includes a photodiode region between the first side and a second side of the second substrate, the second metal stack is operatively coupled to the second substrate, and the second metal stack includes a second material layer at a first side of the second metal stack; and a third element, wherein the third element includes a third substrate and a third metal stack disposed over a first side of the third substrate, the third substrate includes an active region, and the third metal stack includes a third material layer at a first side of the third metal stack; wherein: the first side of the first metal stack is bonded to the first side of the third metal stack and the first metal stack is electrically coupled to the third metal stack; and the first side of the second metal stack is bonded to a second side of the third substrate and the second metal stack is electrically coupled to the third metal stack.