Solid state imaging device, method for producing the same, and electronic apparatus

A solid state imaging device comprising:

• a p-type well region in direct physical contact with a p+-type semiconductor region and an n+-type floating diffusion portion, a portion of the p-type well region being between said p+-type semiconductor region and said n+-type floating diffusion portion;
• a p+-type first vertically elongated region in direct physical contact with said p+-type semiconductor region and an n-type vertically elongated region, said n-type vertically elongated region being in direct physical contact with said p-type well region and said p+-type first vertically elongated region;
• an insulation film in direct physical contact with said p+-type first vertically elongated region and said p+-type semiconductor region, said p-type well region and said n+-type floating diffusion portion being in direct physical contact with said insulation film;
• a p+-type bottom surface region in direct physical contact with said n-type vertically elongated region and said p+-type first vertically elongated region, said p+-type bottom surface region being configured to transfer incident light to said n-type vertically elongated region,
• wherein an impurity concentration of an n-type conductivity in the n-type vertically elongated region is substantially the same throughout the entirety of said n-type vertically elongated region,
• wherein an impurity concentration of a p-type conductivity in the p+-type first vertically elongated region is higher than an impurity concentration of the p-type conductivity in the p-type well region,
• wherein more of a signal charge is accumulable in a pn junction between said n-type vertically elongated region and said p+-type first vertically elongated region than in a pn junction between said n-type vertically elongated region and said p+-type semiconductor region, and the shape of potential is provided such that charges are mainly accumulated in a vertical direction.