Image sensor with improved color crosstalk
AssigneeIntellectual Ventures II LLC
InventorJaroslav Hynecek
Life of this patent
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Abstract
An image sensor comprises a substrate of a first conductivity type. First and second pixels are arrayed over the substrate. A potential barrier is formed in a region of the substrate corresponding to the first pixel but not in a region of the substrate corresponding to the second pixel. The second pixel is responsive to a color having a wavelength longer than the color to which the first pixel is responsive. The potential barrier is doped with dopants by a high energy ion implantation dopants or by an ion implantation or diffusion during epitaxial growth of the P-type epitaxial layer.
Claims19
A method of forming an image sensor, the method comprising:
- initiating a growth of an epitaxial layer;
- stopping the growth of the epitaxial layer at a first depth;
- while the growth of the epitaxial layer is stopped at the first depth, forming a portion of a potential barrier in the epitaxial layer at the first depth in a first pixel region, wherein the potential barrier includes a gap under a second pixel region;
- and
- after forming the portion of the potential barrier, continuing the growth of the epitaxial layer until the epitaxial layer reaches a final depth;
- wherein the gap is arranged to allow electrons to flow from a portion of the epitaxial layer below the potential barrier to a portion of the epitaxial layer above the potential barrier.
A method of forming an image sensor, the method comprising:
- initiating a growth of an epitaxial layer;
- stopping the growth of the epitaxial layer at a first depth;
- while the growth of the epitaxial layer is stopped at the first depth, forming a portion of a potential barrier in the epitaxial layer at the first depth in a first pixel region;
- after forming the portion of the potential barrier, continuing the growth of the epitaxial layer until the epitaxial layer reaches a final depth;
- forming a first photodiode in the first pixel region;
- and
- forming a second photodiode in a second pixel region;
- wherein the portion of the potential barrier is arranged to sweep electrons formed below the portion of the potential barrier to the second photodiode.
A method of forming an image sensor, the method comprising:
- initiating a growth of an epitaxial layer;
- stopping the growth of the epitaxial layer at a first depth;
- while the growth of the epitaxial layer is stopped at the first depth, forming a first portion of a potential barrier in the epitaxial layer at the first depth in a first pixel region, wherein the first portion of the potential barrier includes a gap under a second pixel region;
- after forming the first portion of the potential barrier, continuing the growth of the epitaxial layer until the epitaxial layer reaches a second depth;
- stopping the growth of the epitaxial layer at the second depth;
- while the growth of the epitaxial layer is stopped at the second depth, forming a second portion of the potential barrier in the epitaxial layer at the second depth in a third pixel region;
- after forming the second portion of the potential barrier, continuing the growth of the epitaxial layer until the epitaxial layer reaches a final depth;
- forming a first photodiode in the first pixel region;
- forming a second photodiode in a second pixel region;
- and
- forming a third photodiode in the third pixel region;
- wherein the gap is arranged to allow electrons to flow from a portion of the epitaxial layer below the potential barrier to a portion of the epitaxial layer above the potential barrier.
Dependencies are inferred from the claim text.