EP0738010A2
Expired / Lapsed
EP
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Active pixel sensor integrated with a pinned photodiode
Assignee: Eastman Kodak Co
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Filing: 1996-04-10
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Granted: —
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Expires: 2016-04-10
Abstract
Abstract The optimization of two technologies (CMOS and CCD) wherein a pinned photodiode is integrated into the image sensing element of an active pixel sensor. Pinned photodiodes are fabricated with CCD process steps into the active pixel architecture. Charge integrated within the active pixel pinned photodiode is transferred into the charge sensing node by a transfer gate. The floating diffusion is coupled CMOS circuitry that can provide the addressing capabilities of individual pixels. Alternatively, a buried channel photocapacitor can be used in place of the pinned photodiode.
Inventors
- 👤 Paul P. c/o Eastman Kodak Co. Lee
- 👤 Robert M. C/O Eastman Kodak Co. Guidash
- 👤 Teh-Hsuang c/o Eastman Kodak Co. Lee
- 👤 Eric Gordon c/o Eastman Kodak Co. Stevens
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 12:58
CPC Classifications
H; H10; H10F; H10F39/00; H10F39/011; H10F39/014; H10F39/10; H10F39/12; H10F39/15; H10F39/153; H10F39/18; H10F39/182; H10F39/80; H10F39/803
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
248 words
A method for integrating a pinned photodiode into an active pixel sensor comprising the steps of: providing a substrate made from a semiconductor material of a first conductivity type with a series of masking layers including at least one conductive layer on a major surface of the substrate; forming at least one well of a second conductivity type that is opposite the first conductivity type in area where control circuitry is to be built, and forming an active area over the substrate; patterning at least one transfer gate and a series of local interconnections; forming structures for a charge sensing means, including, creating patterns representing a first set of sources and drains for a predetermined set of transistors, including at least one drain for each of the transfer gates such that the drain is self aligned to the transfer gate; implanting a second conductivity type opposite the first conductivity type as to create the first set of sources and drains; patterning at least one image sensing area adjacent to the transfer gate; implanting within the image sensing area a material of the second conductivity type to create a photodiode; implanting on top of the photodiode a pinning layer comprising the first conductivity type; creating patterns representing a second set of sources and drains for a predetermined set of transistors; implanting the first conductivity type to create the second set of sources and drains; and creating a predetermined set of contacts on first and second set of source drains.
Claim 2
Dependent Claim
38 words
The method of claim 1 further comprising the step of providing a transfer region of the second conductivity type below the transfer gate such that it is essentially self aligned with the transfer gate side opposite the photodiode.
Claim 3
Dependent Claim
48 words
The invention of claim 2 wherein the step of implanting on top of the photodiode a pinning layer further comprises implanting the first conductivity type such that it has at least one edge that overlaps the transfer region and is at the surface of the second conductivity type.
Claim 4
Dependent Claim
35 words
The invention of claim 1 further comprising the step of providing the drain self aligned to the transfer gate is a floating diffusion region that is coupled to the second set of sources and drains.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein the steps relating to implanting the first and second sets of sources and drains are reversed.
Claim 6
Dependent Claim
233 words
An active pixel sensor having at least one pinned photodiode comprising: a substrate of a semiconductor material of a first conductivity type having a series of masking layers including at least one conductive layer, and at least one charge sensing means; at least one transfer gate and a series of local interconnections upon the conductive layer; a first set of implants made from a second conductivity type that is opposite the first conductivity type, the first set of implants functioning as sources and drains for a first set of transistors, including at least one source for each of the transfer gates such that the drain is self aligned to the transfer gate; at least one image sensing area adjacent to the transfer gate formed from one of the sources implanted within the substrate to create a photodiode, with a pinning layer comprising a material of the first conductivity type on top of the photodiode; a second set of implants used as sources and drains for a second set of transistors made from implants of the first conductivity type, the second set of transistors being formed in conjunction with any remaining the first set of transistors that were not used to the create image sensors to form a CMOS control circuit couple to the image sensor by the local connection; and a predetermined set of contacts on first and second set of source drains.
Claim 7
Dependent Claim
38 words
The pixel sensor of claim 6 further comprising a transfer region of the second conductivity type below the transfer gate such that it is essentially self aligned with the side of the transfer gate adjacent to the photodiode.
Claim 8
Dependent Claim
34 words
The pixel sensor of claim 7 wherein the pinning layer further comprises that it has at least one edge that is self aligned to the side of the transfer region adjacent to the photodiode.
Claim 9
Dependent Claim
38 words
The pixel sensor of claim 6 further comprising the charge sensing means is a drain being self aligned to the transfer gate comprising a floating diffusion region that is coupled to the second set of sources and drains.
Claim 10
Dependent Claim
30 words
The pixel sensor of claim 6 wherein the image sensing area is an array of pinned photodiodes that is operatively controlled by the CMOS control circuit via the local interconnections.
References Cited (Backward Citations)
No citation records indexed.
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