Pixel, pixel forming method, imaging device and imaging forming method
A pixel is provided with a photodiode region which includes a photoelectric conversion portion for receiving light and generating electrons, and a charge storage portion for storing electric charge. The pixel is configured in such a manner that an electron exclusion region is provided in the photodiode region with the diameter of a circle having the maximum diameter among circles that can exist in the surface of a region through which electrons can pass in the photodiode region as the width of an electron passage region in the photodiode region, and the width of the electron passage region is smaller than when the electron exclusion region is not provided.
1. A pixel comprising:
a photodiode region including a plurality of photoelectric converting sections which generate electrons when light is received;
at least one charge storage section for storing charge; and
a charge transfer section included in the photodiode region for transferring charge produced in the plurality of photoelectric converting sections to the at least one charge storage section, said charge transfer section being common to said plurality of photoelectric converting sections;
wherein, with a maximum diameter among diameters of circles which exist in an area in the photodiode region through which free electrons pass defined as a width of a free electron passing region in the photodiode region, an electron exclusion region is provided such that the electron exclusion region reduces the width of the free electron passing region in the charge transfer section that is common to said plurality of photoelectric converting sections, thereby providing a shorter charge transfer time through the charge transfer section from the plurality of photoelectric converting sections to the at least one charge storage section,
wherein the electron exclusion region is a region other than the photodiode region or a part of the photodiode region in which ion concentration is reduced, and
wherein the electron exclusion region comprises a drain gate that regulates the charges in the charge transfer section.
2. A pixel according to claim 1 , wherein the width of the free electron passing region is determined in such a way that charge transfer time from the plurality of photoelectric converting sections to the charge storage section is minimized.
3. A pixel according to claim 1 , wherein the width of the free electron passing region is determined in such a way that charge transfer time from the plurality of photoelectric converting sections to the at least one charge storage section is 10 microseconds or less.