Patent ID: 8416330

Claim:
A solid state image pick-up device comprising: a semiconductor substrate having a front surface and a rear surface; a MOSFET formed over said semiconductor substrate at a side of the front surface; and a photo detective layer formed in said semiconductor substrate at a side of the front surface and detecting a near infrared light entering through the rear surface, wherein said photo detective layer comprises: a first region having a first conductive type; a plurality of second regions having a second conductive type opposite to the first conductive type, each of said second regions constituting a photo diode and being separated from each other by said first region; said plurality of second regions having a top surface that is positioned at a side of said front surface and a bottom surface that is positioned at a side of the rear surface; and a third region contacting the bottom surface of one of said second regions and having the first conductive type, said third region being lower in impurity density than said first region, and wherein an impurity concentration of the semiconductor substrate is less than 1×10 17 /cm 3 .