Patent ID: 9553120
Date: 2017-01-24
CPC Classifications: H01L

Claim:
1. An image sensor using backside illumination photodiodes, comprising: a plurality of first metal layers formed in a first wafer including a plurality of backside illumination photodiodes which sense light incident from a backside and output signals and a plurality of transfer transistors which transfer the signals outputted from the backside illumination photodiodes, to floating diffusion nodes, the plurality of first metal layers being electrically connected with the floating diffusion nodes, respectively; a plurality of second metal layers formed in a second wafer including a plurality of pixel transistors which process signals transferred through the floating diffusion nodes and transfer processed signals, the plurality of second metal layers being electrically connected with the pixel transistors, respectively; a plurality of first bonding vias formed in the first wafer, and having one ends which are electrically connected to the first metal layers, respectively; and a plurality of second bonding vias formed in the second wafer, and having one ends which are electrically connected to the second metal layers, respectively, and the other ends which are electrically connected to the other ends of the first bonding vias, respectively, wherein the first bonding vias are formed to have inclined surfaces in the case where a size of the first metal layers is smaller than a size of the second metal layers, and the second bonding vias are formed to have inclined surfaces in the case where a size of the first metal layers is larger than a size of the second metal layers.