Solid-state imaging device

摘要

According to one embodiment, a solid-state imaging device includes a first element formation region surrounded by an element isolation region in a semiconductor substrate having a first and a second surface, an upper element isolation layer on the first surface in the element formation region, a lower element isolation layer between the second surface and the upper element isolation layer, a first photodiode in the element formation region, a floating diffusion in the element formation region, and a first transistor disposed between the first photodiode and the floating diffusion. A side surface of the lower element isolation layer protrudes closer to the transistor than a side surface of the upper element isolation layer.

主权项

1. A solid-state imaging device comprising:
a 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; and a 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, and a 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.