Semiconductor device and imaging device

Abstract

To improve the joining strength between semiconductor chips. In a semiconductor device, a first semiconductor chip includes a first joining surface including a first insulating layer, a plurality of first pads to which a first inner layer circuit insulated by the first insulating layer is electrically connected, and a linear first metal layer arranged on an outside of the plurality of first pads. A second semiconductor chip includes a second joining surface joined to the first joining surface, the second joining surface including a second insulating layer, a plurality of second pads that are arranged in positions facing the first pads and to which a second inner layer circuit insulated by the second insulating layer is electrically connected, and a linear second metal layer arranged in a position facing the first metal layer. A width of the first metal layer and the second metal layer is a width based on a joining strength between the first insulating layer and the second insulating layer and a joining strength between the first metal layer and the second metal layer in an area from an end portion of the first semiconductor chip to the first pad.

What is claimed is: 
     
         1 . A light detecting device, comprising:
 a first substrate including a pixel in a pixel array and a first wiring layer, wherein the first wiring layer includes a first electrode and a second electrode; and   a second substrate including a signal processing circuit and a second wiring layer, wherein the second wiring layer includes a third electrode and a fourth electrode,   wherein the pixel outputs a pixel signal to the signal processing circuit,   wherein the first electrode is bonded to the third electrode,   wherein the first electrode is electrically connected to the pixel array,   wherein the third electrode is electrically connected to the signal processing circuit,   wherein the second electrode and the fourth electrode are disposed outside of the pixel array,   wherein the second electrode is bonded to the fourth electrode,   wherein the second electrode and the fourth electrode are electrically connected to a potential that is different from the pixel signal,   wherein the second electrode is the closest electrode to an end of the first wiring layer, and   wherein the fourth electrode is the closest electrode to an end of the second wiring layer.   
     
     
         2 . The light detecting device of  claim 1 , wherein the first substrate further includes a first via. 
     
     
         3 . The light detecting device of  claim 2 , wherein the first via is electrically connected to the second electrode. 
     
     
         4 . The light detecting device of  claim 3 , wherein the second electrode is electrically connected to a grounding conductor. 
     
     
         5 . The light detecting device of  claim 1 , wherein the first substrate is mechanically bonded to the second substrate. 
     
     
         6 . The light detecting device of  claim 1 , wherein the signal processing circuit is configured to perform processing of the pixel signal. 
     
     
         7 . The light detecting device of  claim 6 , wherein the processing includes analog to digital conversion of the pixel signal. 
     
     
         8 . The light detecting device of  claim 6 , wherein the signal processing circuit is configured to generate a control signal for the pixel. 
     
     
         9 . The light detecting device of  claim 1 , wherein the second electrode is a linear metal layer arranged on an outside of the first electrode. 
     
     
         10 . The light detecting device of  claim 9 , wherein the fourth electrode is a linear metal layer arranged on an outside of the third electrode. 
     
     
         11 . The light detecting device of  claim 10 , wherein the second electrode, the first electrode, the fourth electrode, and the third electrode are formed from copper. 
     
     
         12 . The light detecting device of  claim 1 , wherein the first substrate further includes a first insulating layer, wherein the second electrode, the first electrode, and the first insulating layer form portions of a bonding surface of the first substrate. 
     
     
         13 . The light detecting device of  claim 12 , wherein the second substrate further includes a second insulating layer, wherein the fourth electrode, the third electrode, and the second insulating layer form portions of a bonding surface of the second substrate. 
     
     
         14 . The light detecting device of  claim 13 , wherein the bonding surface of the first substrate and the bonding surface of the second substrate are bonded together. 
     
     
         15 . The light detecting device of  claim 14 , wherein the first electrode is embedded in the first insulating layer, and wherein the third electrode is embedded in the second insulating layer. 
     
     
         16 . The light detecting device of  claim 15 , wherein at least a portion of the first insulating layer between the first electrode and the second electrode and at least a portion of the second insulating layer between the third electrode and the fourth electrode are bonded together. 
     
     
         17 . The light detecting device of  claim 1 , wherein the second electrode and the fourth electrode have a same width. 
     
     
         18 . The light detecting device of  claim 1 , wherein the first substrate includes a plurality of wiring layers. 
     
     
         19 . The light detecting device of  claim 18 , wherein a plurality of vias and the plurality of wiring layers connect the pixel to the processing circuit. 
     
     
         20 . An imaging device, comprising:
 a light detecting device, including:
 a first substrate including a pixel in a pixel array and a first wiring layer, wherein the first wiring layer includes a first electrode and a second electrode; 
 a second substrate including a signal processing circuit and a second wiring layer, wherein the second wiring layer includes a third electrode and a fourth electrode, 
 wherein the pixel outputs a pixel signal to the signal processing circuit, 
 wherein the first electrode is bonded to the third electrode, 
 wherein the first electrode is electrically connected to the pixel array, 
 wherein the third electrode is electrically connected to the signal processing circuit, 
 wherein the second electrode and the fourth electrode are disposed outside of the pixel array, 
 wherein the second electrode is bonded to the fourth electrode, 
 wherein the second electrode and the fourth electrode are electrically connected to a potential that is different from the pixel signal, 
 wherein the second electrode is the closest electrode to an end of the first wiring layer, and 
 wherein the fourth electrode is the closest electrode to an end of the second wiring layer; 
   a microlens provided for the pixel in the plurality of pixels; and   a color filter provided between the microlens and the pixel.