Solid-state imaging device and method for driving the same

A method of manufacturing a back side illumination type solid-state imaging device comprising:

• forming a first pixel separation layer on a light illumination side of a semiconductor substrate in such a manner that an opening in a high-sensitivity pixel is larger than an opening in a low-sensitivity pixel;
• forming a second pixel separation layer located in the semiconductor substrate so as to continue with the first pixel separation layer and in such a manner that an opening in the second pixel separation layer is common to both a high-sensitivity pixel and a low-sensitivity pixel;
• forming a photo diode in each of the high-sensitivity pixel and the low-sensitivity pixel on a signal scan circuit side of the semiconductor substrate;
• forming a signal scan circuit on the signal scan circuit side of the semiconductor substrate;
• and
• forming a first micro lens and a second micro lens both configured to focus light from the photo diode on the high- and low-sensitivity pixels, respectively, the first micro lens being larger than the second micro lens in area.

A back side illumination type solid-state imaging device comprising:

• a unit pixel comprising a high-sensitivity pixel and a low-sensitivity pixel with a lower sensitivity than the high-sensitivity pixel,
• wherein the high-sensitivity pixel comprises a first photo diode configured to photoelectrically convert incident light into charge which is accumulated, and a first read transistor connected to the first photo diode to read signal charge from the first photo diode,
• the low-sensitivity pixel comprises a second photo diode configured to have a lower photosensitivity than the first photo diode and to photoelectrically convert incident light into charge which is accumulated, and a second read transistor connected to the second photo diode to read signal charge from the second photo diode,
• each of the high-sensitivity pixel and the low-sensitivity element comprises a first pixel separation layer located on a light illumination surface side in the semiconductor substrate to separate pixels from each other,
• on the light illumination surface side of the semiconductor substrate, an opening between the first pixel separation layers in the high-sensitivity pixel is larger than an opening between the first pixel separation layers in the low-sensitivity pixel, and
• a plurality of the first pixel separation layers are further arranged on the light illumination surface side in the semiconductor substrate.