Suppression of crosstalk by using backside deep trench isolation for 1.12μm backside illuminated CMOS image sensor

Abstract

1.12μm backside illuminated CMOS image sensor with backside deep trench isolation (DTI) has been demonstrated for the first time. DTI is fabricated on backside pixel surface after wafer bonding and grinding process. Backside DTI makes its layout simple because no transistor isolation exists on backside. We have confirmed about 50% reduction of crosstalk by using backside DTI. The crosstalk of 1.12μm backside DTI pixel is lower than that of 1.4μm BSI pixel. This technology will be promising for 1.12μm and beyond.