Photodiode with different electric potential regions for image sensors
First Claim
Patent Images
1. An image sensor pixel, comprising:
- a photodiode having a first region with a first potential and a second region with a second, higher potential;
a storage node positioned at substantially the same depth as the second region of the photodiode; and
a storage gate operable to selectively transfer charge from the photodiode to the storage node wherein;
the second region is offset in depth from the first region in a semiconductor;
the first region is doped with a first concentration of dopant; and
the second region is doped with a second concentration of dopant that is greater than the first concentration.
1 Assignment
0 Petitions
Accused Products
Abstract
An image sensor pixel is disclosed. The pixel may include a photodiode having a first region with a first potential and a second region with a second, higher potential, with the second region being offset in depth from the first region in a semiconductor chip. A storage node may be positioned at substantially the same depth as the second region of the photodiode. A storage gate may be operable to transfer charge between the photodiode and the storage node.
-
Citations
19 Claims
-
1. An image sensor pixel, comprising:
-
a photodiode having a first region with a first potential and a second region with a second, higher potential; a storage node positioned at substantially the same depth as the second region of the photodiode; and a storage gate operable to selectively transfer charge from the photodiode to the storage node wherein; the second region is offset in depth from the first region in a semiconductor; the first region is doped with a first concentration of dopant; and the second region is doped with a second concentration of dopant that is greater than the first concentration. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
-
-
13. A method of operating an image sensor pixel, comprising:
-
integrating charge in a first region of a photodiode having a first potential and a first concentration of dopant; funneling charge from the first region of the photodiode to a second region of the photodiode responsive to a potential difference between the first and second regions, the second region having a second concentration of dopant greater than the first concentration of dopant; and transferring charge from the second region of the photodiode to a storage node positioned at least partially beneath the first region of the photodiode and at substantially the same depth as the second region. - View Dependent Claims (14, 15, 16)
-
-
17. A method of manufacturing an image sensor pixel, comprising:
-
forming a storage node and a second region of a photodiode on a second surface of a silicon wafer; and forming a first region of the photodiode on a first surface of the silicon wafer, the first region of the photodiode having a lower concentration of doping than the second region, and the first region of the photodiode at least partially covering the storage node formed on the second surface of the silicon wafer. - View Dependent Claims (18, 19)
-
Specification