Solid-state imaging device and camera
A solid-state imaging device which includes a plurality of pixels in an arrangement, each of the pixels including a photoelectric conversion element, pixel transistors including a transfer transistor, and a floating diffusion region, in which the channel width of transfer gate of the transfer transistor is formed to be larger on a side of the floating diffusion region than on a side of the photoelectric conversion element.
1. A solid-state imaging device, comprising a plurality of pixels in an arrangement, wherein:
each of the pixels includes (a) a photoelectric conversion element, (b) pixel transistors including a transfer transistor, and (c) a floating diffusion region having a high impurity concentration region, the high impurity concentration region being a portion of the floating diffusion region;
a channel width of a transfer gate of the transfer transistor is larger on a side of the floating diffusion region than on a side of the photoelectric conversion element;
the transfer gate is shaped with a convex periphery which faces and connects to the floating diffusion region and a linear periphery which faces and connects to the photoelectric conversion element, the transfer gate being arranged on a corner portion of the photoelectric conversion element;
the high impurity concentration region is centered along the convex periphery, and in direct contact with the convex periphery of the transfer gate; and
other portions of the floating diffusion region around the high impurity concentration region and between the high impurity concentration region and a device isolation region are formed as a region having an impurity concentration lower than the high impurity concentration region.
2. The solid-state imaging device according to claim 1 , wherein the high impurity concentration region in the floating diffusion region is used as a contact region.
3. The solid-state imaging device according to claim 2 , wherein:
the pixel transistors other than the transfer transistor are shared in a set with a plurality of photoelectric conversion elements, and
a plurality of transfer transistors are configured to readout signal charges output from the plurality of photoelectric conversion elements.
4. The solid-state imaging device according to claim 3 wherein the plurality of photoelectric conversion elements are arranged horizontally and vertically in an orthogonal coordinate array.
5. The solid-state imaging device according to claim 3 wherein the plurality of photoelectric conversion elements are arranged in an orthogonal coordinate array with two orthogonal axes thereof inclined with respect to horizontal and vertical directions, respectively.
6. The solid-state imaging device according to claim 1 , wherein a plurality of the photoelectric conversion elements are provided and the floating diffusion region is shared with the plurality of photoelectric conversion elements.
7. The solid-state imaging device according to claim 6 , wherein the floating diffusion region is shared with four photoelectric conversion elements as the plurality of photoelectric conversion elements.
8. The solid-state imaging device according to claim 1 , wherein:
the pixel transistors other than the transfer transistor are shared in a set with a plurality of photoelectric conversion elements, and a plurality of transfer transistors configured to readout signal charges output from the plurality of photoelectric conversion elements.
9. The solid-state imaging device according to claim 1 , wherein the plurality of photoelectric conversion elements are arranged horizontally and vertically in an orthogonal coordinate array.
10. The solid-state imaging device according to claim 1 , wherein the plurality of photoelectric conversion elements are arranged in an orthogonal coordinate array with two orthogonal axes thereof inclined with respect to horizontal and vertical directions, respectively.