Frame shutter pixel with an isolated storage node
View Patent ↗A frame shutter type device provides a separated well in which the storage node is located. The storage node is also shielded by a light shield to prevent photoelectric conversion.
1. A method comprising:
receiving a photoelectrically induced signal in an array of photoreceptors on a semiconductor substrate;
controlling each photoreceptor in the array of photoreceptors to simultaneously initiate a common integration period;
at the end of each integration period, controlling each photoreceptor in the array of photoreceptors to transfer its photoelectrically induced signal to a respective storage node located within a respective semiconductor well region formed in the semiconductor substrate; and
preventing each storage node from integrating charge,
wherein each storage node is doped to a first conductivity type, and
wherein a portion of each semiconductor well surrounding each storage node is doped to a second conductivity type.
2. The method of claim 1 , wherein said preventing comprises shielding each storage node with a light shield overlying at least said respective storage node.
3. The method of claim 1 , wherein said preventing comprises shielding each semiconductor well with a light shield overlying said respective semiconductor well.
4. The method of claim 3 , further comprising enabling a first reset operation which resets a value of each storage node, and enabling a second reset operation, which resets a value of each photoreceptor.
5. The method of claim 4 , wherein said first and second reset operations each comprises activating a gate within each semiconductor well.
6. The method of claim 5 , wherein each photoelectrically induced signal is a signal indicative of charge produced by a respective photoreceptor during said integration period.
7. The method of claim 5 , wherein each photoreceptor includes a photodiode.
8. The method of claim 5 , wherein each photoreceptor includes a photogate.
9. The method of claim 3 , further comprising preventing each photoreceptor from acquiring a photoelectrically induced signal which is greater than a pre-determined amount.
10. The method of claim 3 , wherein each of the plurality of photoreceptors in the array comprises a second semiconductor well.
11. The method of claim 10 , further comprising removing charge from each photoreceptor with an anti blooming gate located within each second semiconductor well.
12. The method of claim 10 , further comprising resetting each photoreceptor with reset gates located within each second semiconductor wells.
13. The method of claim 1 , further comprising resetting each storage node with a reset transistor provided within each semiconductor well.
14. The method of claim 1 , further comprising transferring charge from each photoreceptor to each storage node with a transfer gate provided within each semiconductor well region.
15. The method of claim 1 , further comprising isolating each storage node with a bridge diffusion node located within each semiconductor well region.