Partial buried channel transfer device for image sensors
First Claim
1. An image sensor pixel, comprising:
- a photosensitive element disposed in a substrate layer for accumulating an image charge in response to light;
a floating diffusion (“
FD”
) region disposed in the substrate layer to receive the image charge from the photosensitive element; and
a transfer device disposed between the photosensitive element and the FD region to selectively transfer the image charge from the photosensitive element to the FD region, the transfer device including;
a buried channel device including a buried channel gate disposed over a buried channel dopant region; and
a surface channel device in series with the buried channel device, the surface channel device including a surface channel gate disposed over a surface channel region, wherein the surface channel gate has the opposite doping polarity of the buried channel gate.
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Accused Products
Abstract
Embodiments of an image sensor pixel that includes a photosensitive element, a floating diffusion region, and a transfer device. The photosensitive element is disposed in a substrate layer for accumulating an image charge in response to light. The floating diffusion region is dispose in the substrate layer to receive the image charge from the photosensitive element. The transfer device is disposed between the photosensitive element and the floating diffusion region to selectively transfer the image charge from the photosensitive element to the floating diffusion region. The transfer device includes a buried channel device including a buried channel gate disposed over a buried channel dopant region. The transfer device also includes a surface channel device including a surface channel gate disposed over a surface channel region. The surface channel device is in series with the buried channel device. The surface channel gate has the opposite polarity of the buried channel gate.
27 Citations
16 Claims
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1. An image sensor pixel, comprising:
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a photosensitive element disposed in a substrate layer for accumulating an image charge in response to light; a floating diffusion (“
FD”
) region disposed in the substrate layer to receive the image charge from the photosensitive element; anda transfer device disposed between the photosensitive element and the FD region to selectively transfer the image charge from the photosensitive element to the FD region, the transfer device including; a buried channel device including a buried channel gate disposed over a buried channel dopant region; and a surface channel device in series with the buried channel device, the surface channel device including a surface channel gate disposed over a surface channel region, wherein the surface channel gate has the opposite doping polarity of the buried channel gate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An imaging system comprising:
an array of imaging pixels wherein each imaging pixel includes; readout circuitry coupled to the array of imaging pixels to readout image data from each of the image sensor pixels; a photosensitive element disposed in a substrate layer for accumulating an image charge in response to light; a floating diffusion (“
FD”
) region disposed in the substrate layer to receive the image charge from the photosensitive element; anda transfer device disposed between the photosensitive element and the FD region to selectively transfer the image charge from the photosensitive element to the FD region, the transfer device including; a buried channel device including a buried channel gate disposed over a buried channel dopant region; and a surface channel device adjacent to the buried channel device, the surface channel device including a surface channel gate disposed over a surface channel region, wherein the surface channel gate has the opposite dopant polarity of the buried channel gate. - View Dependent Claims (12, 13, 14, 15, 16)
Specification