Solid state imaging device for reducing dark current

A light sensing device, comprising:

• a substrate including a semiconductor layer, the semiconductor layer comprising a light sensing section, a first surface, and a second surface opposite to the first surface, wherein the first surface is at a light incident side of the semiconductor layer;
• a wiring layer on the second surface;
• a first electrode extending from the first surface of the semiconductor layer through the second surface of the semiconductor layer and a surface of the wiring layer to a wiring line disposed in the wiring layer;
• and
• at least three layers over the first surface, the at least three layers comprising a first layer, a second layer, and a third layer,
• wherein the first layer and the third layer are insulating layers, and the second layer comprises a material selected from the group including hafnium oxide, aluminum oxide, zirconium oxide, tantalum oxide, titanium oxide, lanthanum oxide, praseodymium oxide, cerium oxide, neodymium oxide, promethium oxide, samarium oxide, europium oxide, gadolinium oxide, terbium oxide, dysprosium oxide, holmium oxide, erbium oxide, thulium oxide, ytterbium oxide, lutetium oxide, yttrium oxide, hafnium nitride, aluminum nitride, hafnium oxide nitride, and aluminum oxide nitride,
• wherein the second layer is disposed between the first layer and third layer,
• wherein the semiconductor layer includes at least a first photoelectric conversion region, a second photoelectric conversion region, and a pixel separating region extending from the first surface to the second surface,
• wherein the pixel separating region is disposed between the first photoelectric conversion region and the second photoelectric conversion region, and
• wherein at least one of the first layer, the second layer, and the third layer is disposed over the first photoelectric conversion region and the second photoelectric conversion region.