1. An image pickup element comprising:
a first pixel, a second pixel, and a third pixel that share one microlens;
a first boundary that is provided between the first pixel and the second pixel; and
a second boundary that is provided between the first pixel and the third pixel,
wherein when a charge amount of the first pixel is saturated, a first charge amount in which the charge moves from the first pixel to the second pixel via the first boundary is larger than a second charge amount in which the charge moves from the first pixel to the third pixel via the second boundary.
2. The image pickup element according to claim 1,
wherein when the charge amount of the first pixel is saturated, the first boundary is configured to allow a movement of a charge from the first pixel to the second pixel and the second boundary is configured to prevent the movement of the charge from the first pixel to the third pixel.
3. The image pickup element according to claim 1,
wherein the first boundary and the second boundary are configured by a P-type semiconductor, and
wherein a P-type impurity concentration of the first boundary is lower than a P-type impurity concentration of the second boundary.
4. The image pickup element according to claim 1, further comprising:
a fourth pixel, a fifth pixel, and a sixth pixel that share a microlens adjacent to the one microlens;
a third boundary that is provided between the fourth pixel and the fifth pixel; and
a fourth boundary that is provided between the fourth pixel and the sixth pixel,
wherein when a charge amount of the fourth pixel is saturated, a third charge amount in which the charge moves from the fourth pixel to the fifth pixel via the third boundary is larger than a fourth charge amount in which the charge moves from the fourth pixel to the sixth pixel via the fourth boundary, and
wherein the first boundary and the third boundary are provided in directions different from each other.
5. The image pickup element according to claim 4,
wherein when the charge amount of the fourth pixel is saturated, the third boundary is configured to allow a movement of a charge from the fourth pixel to the fifth pixel and the fourth boundary is configured to prevent the movement of the charge from the fourth pixel to the sixth pixel.
6. The image pickup element according to claim 4, further comprising:
color filters that have a plurality of colors;
a first microlens that corresponds to the color filter having one color among the color filters having the plurality of colors; and
a second microlens that corresponds to the color filter having one color and that is adjacent to the first microlens with respect to the color filter having the one color,
wherein the first microlens is shared by the first pixel, the second pixel, and the third pixel, and
wherein the second microlens is shared by the fourth pixel, the fifth pixel, and the sixth pixel.
7. An image pickup apparatus comprising:
an image pickup element; and
a processor configured to perform a correlation calculation based on a signal obtained from at least a part of a plurality of pixels of the image pickup element,
wherein the image pickup element comprises:
a first pixel, a second pixel, and a third pixel that share one microlens;
a first boundary that is provided between the first pixel and the second pixel; and
a second boundary that is provided between the first pixel and the third pixel, and
wherein when a charge amount of the first pixel is saturated, a first charge amount in which the charge moves from the first pixel to the second pixel via the first boundary is larger than a second charge amount in which the charge moves from the first pixel to the third pixel via the second boundary.
8. The image pickup apparatus according to claim 7,
wherein the image pickup element further comprises:
a fourth pixel, a fifth pixel, and a sixth pixel that share a microlens adjacent to the one microlens;
a third boundary that is provided between the fourth pixel and the fifth pixel; and
a fourth boundary that is provided between the fourth pixel and the sixth pixel,
wherein when a charge amount of the fourth pixel is saturated, a third charge amount in which the charge moves from the fourth pixel to the fifth pixel via the third boundary is larger than a fourth charge amount in which the charge moves from the fourth pixel to the sixth pixel via the fourth boundary, and
wherein the first boundary and the third boundary are provided in directions different from each other.
9. An image pickup apparatus according to claim 7,
wherein the processor performs a correlation calculation in a first direction by using added charges of the first pixel and the second pixel.
10. The image pickup apparatus according to claim 8,
wherein the processor performs a correlation calculation in a first direction by using the added charge of the first pixel and the second pixel.
11. The image pickup apparatus according to claim 8,
wherein the processor performs a correlation calculation in a first direction by using added charges of the first pixel and the second pixel and performs a correlation calculation in a second direction different from the first direction by using added charges of the fourth pixel and the fifth pixel.
12. The image pickup apparatus according to claim 8,
wherein when charge amounts of both the first pixel and the second pixel are saturated, a correlation calculation in a second direction is performed by using added charges of the fourth pixel and the fifth pixel.
13. The image pickup apparatus according to claim 7, further comprising a pixel selecting portion configured to select a pixel that is to be used for the correlation calculation from the plurality of pixels sharing the one microlens,
wherein the processor performs the correlation calculation based on the signal obtained from the pixel selected by the pixel selecting portion.
14. An image pickup system comprising:
an image pickup optical system; and
an image pickup apparatus,
wherein the image pickup apparatus comprises:
an image pickup element; and
a processor configured to perform a correlation calculation based on a signal obtained from at least a part of a plurality of pixels of the image pickup element,
wherein the image pickup element comprises:
a first pixel, a second pixel, and a third pixel that share one microlens;
a first boundary that is provided between the first pixel and the second pixel; and
a second boundary that is provided between the first pixel and the third pixel, and
wherein when a charge amount of the first pixel is saturated, a first charge amount in which the charge moves from the first pixel to the second pixel via the first boundary is larger than a second charge amount in which the charge moves from the first pixel to the third pixel via the second boundary.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1-23. (Canceled).
24. A method of forming a pixel cell, the method comprising:
forming a photo-conversion device that generates charge;
forming a gate controlled charge storage region that stores the photo-generated charge;
forming a control gate that controls the charge storage region, and forming a first transistor having its gate between the photo-conversion device and the charge storage region for transferring photo-generated charge from the photo-conversion device to the charge storage region.
25. The method of claim 24, wherein the acts of forming the charge storage region and control gate comprise forming a buried channel metal oxide semiconductor (MOS) capacitor.
26. The method of claim 24, wherein the act of forming the charge storage region comprises forming the charge storage region below a surface of the substrate.
27. The method of claim 24, wherein the act of forming the charge storage region comprises:
forming a doped region of a second conductivity type; and
forming a doped surface layer of a first conductivity type over and in contact with the doped region of a second conductivity type, and wherein the act of forming the control gate comprises forming the control gate over the doped surface layer.
28. The method of claim 24, wherein the act of forming the control gate comprises forming a layer of polysilicon doped with a first conductivity type dopant.
29. The method of claim 24, wherein the act of forming the first transistor comprises forming a shutter transistor for determining an integration time for the pixel cell.
30. The method of claim 24, further comprising:
forming a sensing node; and
forming a second transistor gate of a second transistor between the charge storage region and the sensing node.
31. The method of claim 30, wherein the act of forming the sensing node comprises forming a floating diffusion region.
32. The method of claim 30, wherein the act of forming the control gate comprises forming the control gate at least partially overlapping the first and second transistor gates.
33. The method of claim 24, wherein the act of forming the photo-conversion device comprises forming a pinned photodiode.
34. A method of forming a pixel cell, the method comprising:
forming a photo-conversion device for generating charge;
forming a doped region of a second conductivity type spaced apart from the photo-conversion device;
forming a doped surface layer of a first conductivity type over the doped region of a second conductivity type;
forming a gate of a first transistor between the photo-conversion device and the doped region of a second conductivity type; and
forming a gate electrode over the doped surface layer.
35. The method of claim 34, further comprising:
forming a sensing node; and
forming a gate of a second transistor between the doped region of a second conductivity type and the sensing node.
36. The method of claim 35, wherein the act of forming the gate electrode over the doped surface layer comprises forming the gate electrode overlapping the first and second transistor gates.
37. A method for operating a pixel cell, the method comprising:
generating charge in response to light during an integration period;
transferring the photo-generated charge to a gate controlled charge storage region by operating a gate of a first transistor and operating a control gate that controls the charge storage region; and
storing the photo-generated charge in the charge storage region until a time for readout by operating the control gate.
38. The method of claim 37, wherein the act of storing the photo-generated charge comprises storing the photo-generated charge below a surface of a substrate.
39. The method of claim 37, further comprising determining the length of the integration period for the pixel cell by operating the gate of the first transistor.
40. The method of claim 37, further comprising transferring the photo-generated charge from the charge storage region to a sensing node by operating the control gate and operating a gate of a second transistor.
41. The method of claim 40, wherein the act of transferring the photo-generated charge to the sensing node comprises transferring the photo-generated charge to a floating diffusion region.
42. The method of claim 40, further comprising reading out the photo-generated charge by applying a voltage on the sensing node to a readout circuit.
43. A method of operating an image sensor, the method comprising:
generating charge in response to incident light concurrently within a plurality of pixel cells during an integration time;
transferring the photo-generated charge to gate controlled charge storage regions within respective pixel cells simultaneously by operating gates of shutter transistors and operating control gates that control the charge storage regions;
storing the photo-generated charge in the charge storage regions until a time for readout by operating the control gates; at a time for readout of a first pixel cell, transferring photo-generated charge from a first charge storage region to a first sensing node by operating a gate of an associated first transistor;
sampling a value of the first sensing node;
at a time for readout for a second pixel cell, transferring photo-generated charge from a second charge storage region to a second sensing node by operating a gate of an associated second transistor;
sampling a value of the second sensing node; and
processing the values to obtain an image.
44. The method of claim 43, wherein the act of generating charge comprises generating charge within all pixel cells of an array concurrently.
45. The method of claim 44, wherein the act of transferring the photo-generated charge to a plurality of storage regions comprises transferring the photo-generated charge to charge storage regions within all pixel cells of an array concurrently.