Semiconductor device, fabrication method for a semiconductor device and electronic apparatus

A fabrication method for an image sensor, comprising:

• forming a first insulating film on a first substrate, wherein the first insulating film is formed of a first diffusion preventing material;
• forming a second insulating film on a second substrate, wherein the second insulating film is formed of a second diffusion preventing material;
• forming a first groove pattern in the first insulating film of the first substrate;
• forming a second groove pattern in the second insulating film of the second substrate;
• forming a first electrode film that includes a first electrode material such that the first electrode film is disposed in the first groove pattern formed in the first insulating film of the first substrate;
• forming a second electrode film that includes a second electrode material such that the second electrode film is disposed in the second groove pattern formed in the second insulating film of the second substrate;
• polishing the first electrode film of the first substrate until the first insulating film is exposed forming a first pattern of a first electrode, wherein the first electrode film is embedded in the first groove pattern;
• polishing the second electrode film of the second substrate until the second insulating film is exposed forming a second pattern of a second electrode, wherein the second electrode film is embedded in the second groove pattern;
• and
• bonding the first and second substrates such that the first and second electrodes are joined together,
• wherein
• a size of the second electrode is larger than the size of the first electrode.

A camera system comprising:

• an optical unit;
• and
• a solid-state imaging device including a first substrate having a plurality of pixels and a second substrate having a driving circuit configured to drive each of the plurality of pixels, the solid-state imaging device further including:
• a first electrode at a bonding face of the first substrate, the first electrode being at least partially surrounded by a first insulating film including a first diffusion preventing material with respect to the first electrode;
• and
• a second electrode at a bonding face of the second substrate and joined to the first electrode, the second electrode being at least partially surrounded by a second insulating film including a second diffusion preventing material with respect to the second electrode, wherein
• the first substrate and the second substrate are stacked and a size of the second electrode is larger than a size of the first electrode.