Solid-state imaging device

A solid-state imaging device comprising:na first element formation region surrounded by an element isolation region in a semiconductor substrate having a first surface and a second surface opposite to the first surface;an upper element isolation layer provided on the first surface in the element isolation region;a lower element isolation layer provided between the second surface and the upper element isolation layer;a first photodiode comprising a first impurity layer provided in the element formation region;a floating diffusion provided in the element formation region; anda first transistor disposed between the first photodiode and the floating diffusion and comprising a first gate electrode provided on the first surface,wherein in a direction level with the first surface of the semiconductor substrate, a side surface of the lower element isolation layer facing the transistor across the first impurity layer protrudes closer to the transistor than a side surface of the upper element isolation layer located on the lower element isolation layer,the upper element isolation layer and the lower element isolation layer are impurity layers, anda concentration of the impurity layer as the lower element isolation layer is less than or equal to a concentration of the impurity layer as the upper element isolation layer wherein the upper element isolation layer has the same width as that of the lower element isolation layer.

A solid-state imaging device comprising:na first element formation region surrounded by an element isolation region in a semiconductor substrate having a first surface and a second surface opposite to the first surface;a first photodiode comprising a first impurity layer provided in the element formation region;a floating diffusion provided in the element formation region;a transistor disposed between the first photodiode and the floating diffusion and comprising a first gate electrode provided on the first surface;an upper element isolation layer provided on the first surface in the element isolation region; anda lower element isolation layer provided between the second surface and the upper element isolation layer,wherein a position of a deepest part of a potential distribution of the first photodiode is shifted closer to the transistor than a center of a formation position of the first photodiode in a direction level with the first surface of the semiconductor substrate,wherein the first impurity layer of the photodiode comprises a first region adjacent to the upper element isolation layer in the direction level with the first surface, and a second region adjacent to the lower element isolation layer in the direction level with the first surface, andthe impurity concentration of the first region is substantially the same as the impurity concentration of the second region wherein the photodiode contacts a vertical side of the upper element isolation.