Light receiving device

A light receiving device comprising a photoelectric conversion element for detecting a light to generate photoelectrons formed on a first-conductivity-type semiconductor substrate, wherein

• the light receiving device further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate,
• each of the photoelectron distributors has a first transfer unit for transferring the photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit located on one side of the photoelectric conversion element with the first transfer unit interposed therebetween for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit located on one side of the first transfer unit with the photoelectron hold unit interposed therebetween for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer located on one side of the photoelectron hold unit with the second transfer unit interposed therebetween for storing the transferred photoelectrons and converting the photoelectrons to a voltage,
• a second-conductivity-type impurity region is formed in the vicinity of a surface of the first-conductivity-type semiconductor substrate, and
• a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate below respective gates of the photoelectric conversion element, the first transfer unit, the photoelectron hold unit, and the second transfer unit, and the first-conductivity-type impurity layer has a fourth-level, first-conductivity-type impurity concentration higher than the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate.

A light receiving device comprising a photoelectric conversion element for detecting a light to generate photoelectrons formed on a first-conductivity-type semiconductor substrate, wherein

• the light receiving device further comprises a plurality of photoelectron distributors formed on the first-conductivity-type semiconductor substrate,
• each of the photoelectron distributors has a first transfer unit for transferring the photoelectrons generated in the photoelectric conversion element, a photoelectron hold unit located on one side of the photoelectric conversion element with the first transfer unit interposed therebetween for temporarily holding the photoelectrons generated in the photoelectric conversion element, a second transfer unit located on one side of the first transfer unit with the photoelectron hold unit interposed therebetween for transferring the photoelectrons held in the photoelectron hold unit, and a floating diffusion layer located on one side of the photoelectron hold unit with the second transfer unit interposed therebetween for converting the transferred photoelectrons to a voltage,
• a second-conductivity-type impurity region is formed in the vicinity of a surface of the first-conductivity-type semiconductor substrate,
• a first-conductivity-type impurity layer is formed as an intermediate layer in the first-conductivity-type semiconductor substrate below respective gates of the photoelectric conversion element, the first transfer unit, the photoelectron hold unit, and the second transfer unit, the first-conductivity-type impurity layer has a fifth-level, first-conductivity-type impurity concentration different from the first-conductivity-type impurity concentration of the first-conductivity-type semiconductor substrate, and
• the first-conductivity-type impurity concentration of the first-conductivity-type impurity layer decreases in a direction toward the surface of the first-conductivity-type semiconductor substrate.