Transistor, image sensor with the same, and method of manufacturing the same
AssigneeCrosstek Capital, LLC
InventorMan Lyun Ha
Life of this patent
Estimating the term…
Abstract
Provided is an image sensor including a drive transistor as a voltage buffer, which can suppress generation of secondary electrons from a channel of the drive transistor to prevent generation of image defects caused by dark current. The transistor includes a gate electrode formed on a substrate, source and drain regions formed in the substrate exposed to both sides of the gate electrode, respectively, and an electric field attenuation region formed on the drain region and partially overlapping the gate electrode.
Claims30
(canceled)
The image sensor of claim 42, wherein the source and drain regions have an asymmetrical structure.
The image sensor of claim 42, wherein the drain region comprises:
- a first doping region formed at an interface of the substrate and partially overlapping the gate electrode;
- and
- a second doping region spaced apart from the gate electrode and formed under the first doping region.
The image sensor of claim 42, wherein the source region comprises:
- a first doping region formed at an interface of the substrate and aligned with the gate electrode;
- and
- a second doping region spaced apart from the gate electrode and formed under the first doping region.
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The image sensor of claim 42, wherein the drain region comprises:
- a first doping region aligned with the gate electrode and formed under an electric field attenuation region, wherein the electric field attenuation region partially overlaps the first doping region and the gate electrode;
- and
- a second doping region spaced apart from the gate electrode and formed under the first doping region.
16-21. (canceled)
A method of manufacturing an image sensor, the method comprising:
- forming a photo detection device to gather photo-generated charge;
- forming a floating diffusion region;
- forming a transfer transistor configured to transfer photo-generated charge from the photo detection device to the floating diffusion region;
- and
- forming a drive transistor configured to generate a signal output representative of the potential of the floating diffusion region, wherein said forming a drive transistor includes:
- forming source and drain regions in a substrate and spaced apart from each other;
- forming a gate electrode on the substrate to overlap a portion of the drain region;
- and
- forming a doping region below the source and drain regions.
The method of claim 43, wherein the first doping region has a lower concentration than that of the second doping region.
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33-41. (canceled)
An image sensor, comprising:
- a photo detection device configured to gather photo-generated charge;
- a floating diffusion region;
- a transfer transistor configured to transfer photo-generated charge from the photo detection device to the floating diffusion region;
- a reset transistor configured to set a potential of the floating diffusion region to a desired value;
- a drive transistor configured to generate a signal output representative of the potential of the floating diffusion region;
- and
- a select transistor configured to transmit the signal output from the source region of the drive transistor,
- wherein the drive transistor includes:
- a gate electrode coupled to the floating diffusion region;
- a source region aligned with a first side of the gate electrode;
- a drain region coupled to a power voltage terminal, disposed on a second side of the gate electrode opposite the first side, and comprising a portion that extends under the gate electrode;
- a doping region formed below the source region and having a conductivity type different than the source region;
- and
- a doping region formed below the drain region and having a conductivity type different than the drain region.
Dependencies are inferred from the claim text.