Patent EP0854516A2 successfully refreshed from Google Patents.
EP0854516A2
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EP
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Partially pinned photodiode for solid state image sensors
Assignee: Omnivision Technologies Inc
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Filing: 1998-01-08
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Granted: —
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Expires: 2018-01-08
Abstract
Abstract A pixelated image sensor having comprising a partially pinned photodiode which is formed a semiconductor of a first conductivity type formed on a surface of the sensor with at least one photodiode formed, within the semiconductor near the surface, the photodiode being formed from a second conductivity type opposite the first conductivity type; a pinning layer formed on the surface over at least a portion of the photodiode creating a pinned photodiode region, the pinning layer being formed from the first conductivity type; and an unpinned region formed near the surface in an area outside the portion used to form the pinning layer, the unpinned region is formed as a floating region that is employed as a capacitor. The partially pinned photodiode is useful in expanding the fill factor of photodetectors employing photodiode technology.
Inventors
- 👤 Teh-Hsuang c/o Eastman Kodak Company Lee
- 👤 Robert Michael c/o Eastman Kodak Company Guidash
- 👤 Paul Poo-Kam c/o Eastman Kodak Company Lee
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 12:57
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/011; H10F39/014; H10F39/10; H10F39/12; H10F39/18; H10F39/186; H10F39/80; H10F39/803; H10F39/802; Y; Y02; Y02E; Y02E10/00; Y02E10/50; Y02E10/547
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
121 words
An image sensor having at least one pixel
comprising: a semiconductor of a first conductivity type
within the sensor, the semiconductor being formed on a
surface of the sensor; at least one photodiode formed, within the
semiconductor near the surface, the photodiode being
formed from a second conductivity type opposite the first
conductivity type; a pinning layer formed on the surface over at
least a portion of the photodiode creating a pinned
photodiode region, the pinning layer being formed from
the first conductivity type; an unpinned region formed within the photodiode
near the surface in an area outside the portion used to
form the pinning layer; and a sensing node coupled to the unpinned region
interfacing the photodiode to external circuitry.
Claim 2
Dependent Claim
16 words
The image sensor of claim 1 further
comprising a control circuit operatively coupled to the
pixel.
Claim 3
Dependent Claim
21 words
The image sensor of claim 1 further
comprising reset means for removing charge from the
photodiode portion to a drain area.
Claim 4
Dependent Claim
23 words
The image sensor of claim 1 wherein the
unpinned region is formed having a layer of the second
conductivity type at the surface.
Claim 5
Dependent Claim
34 words
The image sensor of claim 1 wherein the
sensor is an active pixel sensor and the unpinned region
is a floating region that functions as a capacitor that
is operatively coupled to a transistor.
Claim 6
Dependent Claim
16 words
The image sensor of claim 5 wherein the
transistor is operatively coupled to CMOS control
circuitry.
Claim 7
Dependent Claim
31 words
The image sensor of claim 1 wherein the
pinned photodiode region further comprises a gradient
dopant level formed to create an electrostatic gradient
capable of pushing electrons towards the unpinned region.
Claim 8
Dependent Claim
19 words
The image sensor of claim 1 further
comprising utilization means for facilitating dynamic
range compression operation of the sensor.
Claim 9
Dependent Claim
19 words
The image sensor of claim 1 wherein the
control circuitry is selected from one of either CMOS,
PMOS, NMOS.
Claim 10
Independent Claim
127 words
A method of making an image sensor
comprising the steps of: firstly providing a semiconductor having a
first conductivity type within the sensor, such that the
semiconductor is formed on a surface of the sensor; secondly providing at least one photodiode
within the semiconductor near the surface from a second
conductivity type opposite the first conductivity type; thirdly providing a pinning layer from the
first conductivity type formed on the surface over at
least a portion of the photodiode creating a pinned
photodiode region; fourthly providing an unpinned region within
the photodiode outside the portion on the surface used to
form the pinning layer such that the unpinned region is
formed near the surface and is coupled to a sensing node
interfacing the photodiode to external circuitry
References Cited (Backward Citations)
US5262871A
Cited
EP0738010A2
Cited
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