Image sensor pixels with vertical charge transfer
AssigneeAptina Imaging Corporation
InventorJaroslav Hynecek
Life of this patent
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Abstract
Image sensors having image sensor pixels with stacked photodiodes are provided. An image sensor pixel may include a shallow potential well located in a shallow implant region and a deep potential well located in a deep implant region. The shallow implant region and the deep implant region may be separated by a potential barrier. The image sensor pixel may have a given transfer gate to transfer charge from the shallow well to a floating diffusion node. The image sensor pixel may have an additional transfer gate to transfer charge from the deep well to the shallow well via a vertical transfer region located under the additional transfer gate. Image sensor pixels formed using this structure may exhibit higher pixel densities, higher image resolution, and higher sensitivity.
Claims13
A stacked photodiode image sensor pixel in an image sensor array formed in a semiconductor substrate, comprising:
- a first photodiode formed using a first p-type doped region and a first n-type doped region;
- a second photodiode formed using a second p-type doped region and a second n-type doped region, wherein the first photodiode is stacked vertically above the second photodiode;
- a vertical charge transfer region transfer gate;
- and
- a vertical charge transfer region that is located below the vertical charge transfer region transfer gate and that is adjacent to the first and second photodiodes, wherein the vertical charge transfer region transfer gate assists in transferring charge collected in the second n-type doped region to the first n-type doped region through the vertical charge transfer region.
An image sensor, comprising:
- a plurality of image sensor pixels;
- and
- a color filter array formed over the plurality of image sensor pixels, wherein the color filter array includes non-clear color filters and clear color filters, wherein each image sensor pixel in the plurality of image sensor pixels comprises:
- a first photodiode formed from a first p-type doped region and a first n-type doped region;
- a second photodiode formed from a second p-type doped region and a second n-type doped region, wherein the first photodiode is stacked vertically above the second photodiode;
- a vertical charge transfer region transfer gate;
- and
- a vertical charge transfer region that is located below the vertical charge transfer region transfer gate and that is adjacent to the first and second photodiodes, wherein the vertical charge transfer region transfer gate is used to transfer charge collected in the second n-type doped region to the first n-type doped region through the vertical charge transfer region.
Dependencies are inferred from the claim text.