Abstract: A method of image sensor fabrication includes forming a photodiode and a floating diffusion in a first semiconductor material, and removing part of an oxide layer disposed proximate to a seed area on a surface of the first semiconductor material. The method also includes depositing a second semiconductor material over the surface of the first semiconductor material, and annealing the first semiconductor material and second semiconductor material. A portion of the second semiconductor material is etched away to form part of a source follower transistor, and dopant is implanted into the second semiconductor material to form a first doped region, a third doped region, and a second doped region. The second doped region is laterally disposed between the first doped region and the third doped region, and the second doped region is a channel of the source follower transistor.

Abstract: An image sensor includes a plurality of photodetectors that are identically sized and fabricated in semiconductor material with identical semiconductor processing conditions. The photodetectors are organized into virtual high-low sensitivity groupings, each including a first photodetector and a second photodetector. A plurality of attenuators is disposed over the semiconductor material. Each one of the plurality of attenuators is disposed along an optical path between a microlens and the first photodetector of each virtual high-low sensitivity grouping such that all incident light directed into the first photodetector is directed through a respective one of the plurality of attenuators. There is no attenuator along a second optical path between a microlens and the second photodetector of each virtual high-low sensitivity grouping such that all the incident light directed into the second photodetector is not directed through one of the plurality of attenuators.

Abstract: An avalanche photodiode has a first diffused region of a first diffusion type overlying at least in part a second diffused region of a second diffusion type; and a first minority carrier sink region disposed within the first diffused region, the first minority carrier sink region of the second diffusion type and electrically connected to the first diffused region. In particular embodiments, the first diffusion type is N-type and the second diffusion type is P-type, and the device is biased so that a depletion zone having avalanche multiplication exists between the first and second diffused regions.

Abstract: Apparatuses and methods for image sensors with pixels that reduce or eliminate flicker induced by high intensity illumination are disclosed. An example image sensor may include a photodiode, a transfer gate, an anti-blooming gate, and first and second source follower transistors. The photodiode may capture light and generate charge in response, and the photodiode may have a charge capacity. The transfer gate may selectively transfer charge to a first floating diffusion, and the anti-blooming gate may selectively transfer excess charge to a second floating diffusion when the generated charge is greater than the photodiode charge capacity.

Abstract: Apparatuses and methods for image sensors with pixels that reduce or eliminate flicker induced by high intensity illumination are disclosed. An example image sensor may include a photodiode, a transfer gate, an anti-blooming gate, and first and second source follower transistors. The photodiode may capture light and generate charge in response, and the photodiode may have a charge capacity. The transfer gate may selectively transfer charge to a first floating diffusion, and the anti-blooming gate may selectively transfer excess charge to a second floating diffusion when the generated charge is greater than the photodiode charge capacity.

Abstract: A PDAF imaging system includes an image sensor and an image data processing unit. The image sensor has an asymmetric-microlens PDAF detector that includes: (a) a plurality of pixels forming a sub-array having at least two rows and two columns, and (b) a microlens located above each of the plurality of pixels and being rotationally asymmetric about an axis perpendicular to the sub-array. The axis intersects a local extremum of a top surface of the microlens. The image data processing unit is capable of receiving electrical signals from each of the plurality of pixels and generating a PDAF signal from the received electrical signals. A method for forming a gull-wing microlens includes forming, on a substrate, a plate having a hole therein. The method also includes reflowing the plate.

Abstract: A stacked-filter image-sensor spectrometer includes an image sensor, a first color filter array, and a second color filter array. The image sensor has a pixel array including a plurality of pixels. The first color filter array has a plurality of first color filters, wherein each first color filter is located above at least one pixel. The second color filter array is located between the first color filter array and the image sensor and has a plurality of second color filters. Each second color filter is located above at least one pixel. Each of the plurality of pixels has thereabove a compound color filter formed of one of the second color filters and one of the first color filters, the second filter having a second passband that partially overlaps a first passband of the first color filter in a first overlapping wavelength range.

Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material between a first side and a second side of the semiconductor material. The image sensor also includes a plurality of hybrid deep trench isolation (DTI) structures disposed in the semiconductor material, where individual photodiodes in the plurality of photodiodes are separated by individual hybrid DTI structures. The individual hybrid DTI structures include a shallow portion that extends from the first side towards the second side of the semiconductor material, and the shallow portion includes a dielectric region and a metal region such that at least part of the dielectric region is disposed between the semiconductor material and the metal region. The hybrid DTI structures also include a deep portion that extends from the shallow portion and is disposed between the shallow portion and the second side of the semiconductor material.

Abstract: An image sensor includes photodiodes arranged in semiconductor material. Each of the photodiodes is identically sized and is fabricated in the semiconductor material with identical semiconductor processing conditions. The photodiodes are organized into virtual large-small groupings including a first photodiode and a second photodiode. Microlenses are disposed over the semiconductor material with each of microlenses disposed over a respective photodiode. A first microlens is disposed over the first photodiode, and a second microlens is disposed over the second photodiode. A mask is disposed between the first microlens and the first photodiode. The mask includes an opening through which a first portion of incident light directed through the first microlens is directed to the first photodiode. A second portion of the incident light directed through the first microlens is blocked by the mask from reaching the first photodiode. There is no mask between the second microlens and the second photodiode.

Abstract: An image sensor includes a semiconductor material having an illuminated surface and a non-illuminated surface. A plurality of photodiodes is disposed in the semiconductor material to receive image light through the illuminated surface. The semiconductor material includes silicon and germanium, and the germanium concentration increases in a direction of the non-illuminated surface. A plurality of isolation regions is disposed between individual photodiodes in the plurality of photodiodes. The plurality of isolation regions surround, at least in part, the individual photodiodes and electrically isolate the individual photodiodes.

Abstract: A pixel array for use in a high dynamic range image sensor includes a plurality of pixels arranged in a plurality of rows and columns in the pixel array. Each one of the pixels includes a linear subpixel and a log subpixel disposed in a semiconductor material. The linear subpixel is coupled to generate a linear output signal having a linear response, and the log subpixel is coupled to generate a log output signal having a logarithmic response in response to the incident light. A bitline is coupled to the linear subpixel and to the log subpixel to receive the linear output signal and the log output signal. The bitline is one of a plurality of bitlines coupled to the plurality of pixels. Each one of the plurality of bitlines is coupled to a corresponding grouping of the plurality of pixels.

Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material, and a through-semiconductor-via coupled to a negative voltage source. Deep trench isolation structures are disposed between individual photodiodes in the plurality of photodiodes to electrically and optically isolate the individual photodiodes. The deep trench isolation structures include a conductive material coupled to the through-semiconductor-via, and a dielectric material disposed on sidewalls of the deep trench isolation structures between the semiconductor material and the conductive material.

Abstract: An image sensor includes a photodiode disposed in a first semiconductor material and a floating diffusion disposed proximate to the photodiode in the first semiconductor material. A source follower transistor is disposed in part in a second semiconductor material and includes: a first doped region, a third doped region, and a second doped region with an opposite polarity as the first doped region and the third doped region, and a gate electrode coupled to the floating diffusion and disposed in the first semiconductor material and aligned with the second doped region in the second semiconductor material of the source follower transistor.

Abstract: An avalanche photodiode sensor includes a plurality of avalanche photodiodes disposed in a semiconductor material where individual avalanche photodiodes in the plurality of avalanche photodiodes have an internal electric field parallel with a first surface of the semiconductor material. The individual avalanche photodiodes in the plurality of avalanche photodiodes include a p-doped semiconductor region which extends into the semiconductor material, and an n-doped semiconductor region which extends into the semiconductor material. The internal electric field extends between the p-doped semiconductor region and the n-doped semiconductor region. Processing methods as examples are also proposed.

Abstract: A photodetector includes a first doped region disposed in a semiconductor material and a second doped region disposed in the semiconductor material. The second doped region is electrically coupled to the first doped region, and the second doped region is of an opposite majority charge carrier type as the first doped region. The photodetector also includes a quantum dot layer disposed in a trench in the semiconductor material, and the quantum dot layer is electrically coupled to the second doped region. A transfer gate is disposed to permit charge transfer from the second doped region to a floating diffusion.

Abstract: An image sensor includes a plurality of photodetectors that are identically sized and fabricated in semiconductor material with identical semiconductor processing conditions. The photodetectors are organized into virtual high-low sensitivity groupings, each including a first photodetector and a second photodetector. A plurality of attenuators is disposed over the semiconductor material. Each one of the plurality of attenuators is disposed along an optical path between a microlens and the first photodetector of each virtual high-low sensitivity grouping such that all incident light directed into the first photodetector is directed through a respective one of the plurality of attenuators. There is no attenuator along a second optical path between a microlens and the second photodetector of each virtual high-low sensitivity grouping such that all the incident light directed into the second photodetector is not directed through one of the plurality of attenuators.

Abstract: A photon detection device includes a single photon avalanche diode (SPAD) disposed in a semiconductor layer. A guard ring structure is disposed in the semiconductor layer surrounding the SPAD to isolate the SPAD. A well region is disposed in the semiconductor layer surrounding the guard ring structure and disposed along an outside perimeter of the photon detection device. A contact region is disposed in the well region only in a corner region of the outside perimeter such that there is no contact region disposed along side regions of the outside perimeter. A distance between an inside edge of the guard ring structure and the contact region in the corner region of the outside perimeter is greater than a distance between the inside edge of the guard ring structure and the side regions of the outside perimeter such that an electric field distribution is uniform around the photon detection device.

Abstract: A resonant-filter image sensor includes a pixel array including a plurality of pixels and a microresonator layer above the pixel array. The microresonator layer includes a plurality of microresonators formed of a first material with an extinction coefficient less than 0.02 at a free-space wavelength of five hundred nanometers. Each of the plurality of pixels may have at least one of the plurality of microresonators at least partially thereabove. The resonant-filter image sensor may further include a layer covering the microresonator layer that has a second refractive index less than a first refractive index, the first refractive index being the refractive index of the first material. Each microresonator may be one of a parallelepiped, a cylinder, a spheroid, and a sphere.

Abstract: An image sensor for detecting light-emitting diode (LED) without flickering includes a pixel array with pixels. Each pixel including subpixels including a first and a second subpixel, dual floating diffusion (DFD) transistor, and a capacitor coupled to the DFD transistor. First subpixel includes a first photosensitive element to acquire a first image charge, and a first transfer gate transistor to selectively transfer the first image charge from the first photosensitive element to a first floating diffusion (FD) node. Second subpixel includes a second photosensitive element to acquire a second image charge, and a second transfer gate transistor to selectively transfer the second image charge from the second photosensitive element to a second FD node. DFD transistor coupled to the first and the second FD nodes. Other embodiments are also described.

Abstract: An image sensor includes a semiconductor material having an illuminated surface and a non-illuminated surface. A plurality of photodiodes is disposed in the semiconductor material to receive image light through the illuminated surface. The semiconductor material includes silicon and germanium, and the germanium concentration increases in a direction of the non-illuminated surface. A plurality of isolation regions is disposed between individual photodiodes in the plurality of photodiodes. The plurality of isolation regions surround, at least in part, the individual photodiodes and electrically isolate the individual photodiodes.