Eastman-kodak Company

Omnivision Technologies, Inc.

Semiconductor Components Industries, LLC

Truesense Imaging, Inc.

Eric Gordon Stevens

Robert Michael Guidash

Hung Q Doan

Teh-Hsuang Lee

Stephen L Kosman

David N Nichols

Paul P Lee

James P Lavine

Edmund Kenneth Banghart

David L Losee

John Paul McCarten

Herbert J Erhardt

Joseph R Summa

Edward T Nelson

Cristian A Tivarus

Constantine N Anagnostopoulos

Christopher Parks

Shen Wang

John P Shepherd

William F DesJardin

Kenneth Alan Parulski

Jaroslav Hynecek

Gilbert Allan Hawkins

Timothy John Tredwell

David Michael Boisvert

Eric J Meisenzahl

Vladimir Korobov

Robert H Hibbard

Win-Chyi Chang

Michael J Gaboury

Bruce C Burkey

Robert P Fabinski

Paul L Roselle

Charles V Stancampiano

Bartosz Piotr Banachowicz

Todd J Anderson

Robert H Philbrick

Muhammad Maksudur Rahman

Daniel Tekleab

Hirofumi Komori

Georgia R Torok

Stephen Kosman

Webster

John P Mccarten

Hung Quoc Doan

Cristian Alexandru Tivarus

Todd Jeffery Anderson

David Newell Nichols

An image sensor with a pinned photodiode includes a photodiode formed in a substrate by implanting dopants of a first type through one or more dielectric layers formed over the substrate. A pinning layer for the photodiode may be formed by implanting dopants of a second type through the same one or more dielectric layers. The pinning layer may be formed over a photodiode region of the substrate. The concentration of dopants of the second type may have a maximum value in dielectric layers over the photodiode that exceeds the concentration of dopants of the second type in the substrate below. The photodiode and pinning layer may both be formed by implanting ions of the first and second type respectively through a dielectric layer formed after etching away a portion of another dielectric layer, having a different thickness, and having different optical transmission properties than the another dielectric layer.

Method of forming a shallow pinned photodiode

Various embodiments of the present technology may comprise methods and apparatus for a CCD image sensor. The image sensor may comprise a center channel disposed along a horizontal center line of the pixel array for collecting and transferring charge. The center channel is electrically coupled to a lateral overflow drain. In various embodiments, the image sensor may comprise a light shield under a gap between neighboring microlenses, such as a gap along the center line, to block light, such as to maintain a uniform, spatial sampling pattern across the device. In various embodiments, the image sensor may comprise a barrier region disposed between the center channel and the lateral overflow drain, for example to prevent charge from the lateral overflow drain being injected back into the center channel and adjacent pixels.

Methods and apparatus for a CCD image sensor

An image sensor pixel may include a photodiode, a floating diffusion, and a transfer gate. A buried channel may be formed under the transfer gate. The buried channel may extend from the floating diffusion to overlap a portion of the transfer gate without extending completely beneath the transfer gate or reaching the photodiode. The buried channel may provide a path for antiblooming current from the photodiode to reach the floating diffusion, while allowing for the transfer gate off voltage to remain high enough to prevent transfer gate dark current from flowing into the photodiode.

Apparatus and methods for buried channel transfer gate

In electron multiplying charge coupled device (EMCCD) image sensors, electron traps in the dielectric stack underneath charge multiplication electrodes may cause undesirable gain ageing. To reduce the gain ageing drift effect, a dielectric stack may be formed that does not include electron traps in regions underneath charge multiplication electrodes. To accomplish this, silicon nitride in the dielectric stack may be removed in regions underneath the charge multiplication electrodes. The EMCCD image sensors can thus be fabricated with a stable charge carrier multiplication gain during their operational lifetime.

EMCCD image sensor with stable charge multiplication gain

A charge-coupled device (CCD) image sensor is provided. The CCD image sensor may include an array of photosensors that transfer charge to multiple vertical CCD shift registers, which then in turn transfer the charge to a horizontal CCD shift register. The horizontal CCD shift register then feeds an output buffer circuit. The output buffer circuit can include a load transistor implemented using a buried-channel drain (BCD) structure. The load transistor may include a gate conductor, a source diffusion region, a drain diffusion region, and a buried-channel drain region that at least partially extends under the gate conductor. The BCD region may be formed before or after the formation of the gate conductor. If desired, the BCD region can also be formed at the source edge. An image sensor configured in this way can exhibit higher source-drain breakdown voltages, enhanced amplifier gain, and reduced amplifier glow.

Image sensor with buried-channel drain (BCD) transistors

An image sensor is fabricated by forming transfer gates over a substrate layer. A transfer gate is disposed between a respective shared charge-to-voltage conversion region and a photodetector associated with the shared charge-to-voltage conversion region. The transfer gates of each shared charge-to-voltage conversion region are spaced apart to form a conversion region gap. A masking conformal dielectric layer is deposited over the image sensor, covers the transfer gates, fills each conversion region gap, and is etched to form sidewall spacers along an outside edge of each transfer gate with a portion remaining in each conversion region gap and disposed over the substrate layer in each conversion region gap. Source/drain regions are implanted in the substrate layer where an implant region is formed in the transfer gates. The masking conformal dielectric layer in each conversion gap masks the source/drain implant Each charge-to-voltage conversion region is substantially devoid of the implant region.

Image sensor with doped transfer gate

An image sensor includes an array of pixels, with at least one pixel including a photodetector formed in a substrate layer and a transfer gate disposed adjacent to the photodetector. The substrate layer further includes multiple charge-to-voltage conversion regions. A single photodetector can transfer collected charge to a single charge-to-voltage conversion region, or alternatively multiple photodetectors can transfer collected charge to a common charge-to-voltage conversion region shared by the photodetectors. An implant region formed when dopants are implanted into the substrate layer to form source/drain implant regions is disposed in only a portion of each transfer gate while each charge-to-voltage conversion region is substantially devoid of the implant region.

A lateral overflow drain and a channel stop are fabricated using a double mask process. Each lateral overflow drain is formed within a respective channel stop. Due to the use of two mask layers, one edge of each lateral overflow drain is aligned, or substantially aligned, with an edge of a respective channel stop.

Lateral overflow drain and channel stop regions in image sensors

A back-illuminated image sensor includes a sensor layer disposed between an insulating layer and a circuit layer electrically connected to the sensor layer. An imaging area includes a plurality of photodetectors is formed in the sensor layer and a well that spans the imaging area. The well can be disposed between the backside of the sensor layer and the photodetectors, or the well can be a buried well formed adjacent to the backside of the sensor layer with a region including formed between the photodetectors and the buried well. One or more side wells can be formed laterally adjacent to each photodetector. The dopant in the well has a segregation coefficient that causes the dopant to accumulate on the sensor layer side of an interface between the sensor layer and the insulating layer.

Back-illuminated CMOS image sensors

Shallow trench isolation regions are disposed in an n-type silicon semiconductor layer laterally adjacent to a collection region of a photodetector and laterally adjacent to a charge-to-voltage conversion region. The shallow trench isolation regions each include a trench disposed in the silicon semiconductor layer and a first dielectric structure disposed along an interior bottom and sidewalls of each trench. A second dielectric structure is disposed over the pinning layer. The dielectric structures include a silicon nitride layer disposed over an oxide layer. An n-type isolation layer is disposed along only a portion of the exterior bottom of the trench and the exterior sidewall of the trench immediately adjacent to the photodetector. The n-type isolation layer is not disposed along the remaining portion of the bottom or the opposing exterior sidewall of the trench.

Photodetector isolation in image sensors

Method of forming lateral overflow drain and channel stop regions in image sensors

A back-illuminated image sensor includes a sensor layer of a first conductivity type having a frontside and a backside opposite the frontside. One or more frontside regions of a second conductivity type are formed in at least a portion of the frontside of the sensor layer. A backside region of the second conductivity type is formed in the backside of the sensor layer. A plurality of frontside photodetectors of the first conductivity type is disposed in the sensor layer. A distinct plurality of backside photodetectors of the first conductivity type separate from the plurality of frontside photodetectors are formed in the sensor layer contiguous to portions of the region of the second conductivity type. A voltage terminal is disposed on the frontside of the sensor layer. One or more connecting regions of the second conductivity type are disposed in respective portions of the sensor layer between the voltage terminal and the backside region for electrically connecting the voltage terminal to the backside region.

Back-illuminated image sensors having both frontside and backside photodetectors

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Webster, NY, United States of America

Eric Gordon Stevens