Abstract: An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by square toroidal microlenses to direct light incident on the pixels onto photosensitive regions of the pixels. The square toroidal microlenses may be formed as first and second sets of microlenses aligned with every other SPAD pixel and may allow the square toroidal microlenses to be formed without gaps between adjacent lenses. Additionally or alternatively, a central portion of each square toroidal microlenses may be filled by a fill-in microlens. Together, the square toroidal microlenses and the fill-in microlenses may form convex microlenses over each SPAD pixel. The fill-in microlenses may be formed from material having a higher index of refraction than material that forms the square toroidal microlenses.

Abstract: An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by square toroidal microlenses to direct light incident on the pixels onto photosensitive regions of the pixels. The square toroidal microlenses may be formed as first and second sets of microlenses aligned with every other SPAD pixel and may allow the square toroidal microlenses to be formed without gaps between adjacent lenses. Additionally or alternatively, a central portion of each square toroidal microlenses may be filled by a fill-in microlens. Together, the square toroidal microlenses and the fill-in microlenses may form convex microlenses over each SPAD pixel. The fill-in microlenses may be formed from material having a higher index of refraction than material that forms the square toroidal microlenses.

Abstract: An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by square toroidal microlenses to direct light incident on the pixels onto photosensitive regions of the pixels. The square toroidal microlenses may be formed as first and second sets of microlenses aligned with every other SPAD pixel and may allow the square toroidal microlenses to be formed without gaps between adjacent lenses. Additionally or alternatively, a central portion of each square toroidal microlenses may be filled by a fill-in microlens. Together, the square toroidal microlenses and the fill-in microlenses may form convex microlenses over each SPAD pixel. The fill-in microlenses may be formed from material having a higher index of refraction than material that forms the square toroidal microlenses.

Abstract: A high dynamic range image sensor may include a plurality of pixel groups. One or more pixel groups may include attenuated pixels in addition to unattenuated pixels. The unattenuated pixels may include a photosensitive area, a color filter element and a microlens of a first size. Each attenuated pixel may include a photosensitive area, a color filter element, a neutral density filter, and a microlens of a second size that is smaller than the first size. The color filter elements for each pixel in a given pixel group may be the same color. The neutral density filter may attenuate light for the attenuated pixels, increasing dynamic range of the image sensor. The microlenses of varying sizes may redirect light from attenuated pixels towards unattenuated pixels, further increasing the dynamic range.

Abstract: A high dynamic range image sensor may include a plurality of pixel groups. One or more pixel groups may include attenuated pixels in addition to unattenuated pixels. The unattenuated pixels may include a photosensitive area, a color filter element and a microlens of a first size. Each attenuated pixel may include a photosensitive area, a color filter element, a neutral density filter, and a microlens of a second size that is smaller than the first size. The color filter elements for each pixel in a given pixel group may be the same color. The neutral density filter may attenuate light for the attenuated pixels, increasing dynamic range of the image sensor. The microlenses of varying sizes may redirect light from attenuated pixels towards unattenuated pixels, further increasing the dynamic range.

Abstract: An image sensor may include one or more phase detection pixel groups. A phase detection pixel group may include at least two phase detection pixels with respective photosensitive areas and a per-group microlens that covers all of the phase detection pixels in that group. Each phase detection pixel may have an asymmetric response to incident light. The phase detection pixel group may also include per-pixel microlenses that each cover a respective photosensitive area of a phase detection pixel. The per-group microlens may overlap the per-pixel microlenses. A low-index filler may be interposed between the per-group microlens and the per-pixel microlenses. The per-pixel microlenses may be incorporated into phase detection pixel groups in both front-side illuminated image sensors and back-side illuminated image sensors. The phase detection pixel groups may have a 2×2 arrangement.

Abstract: An image sensor may include phase detection pixels that gather phase detection data. The phase detection pixels may be formed in phase detection pixel groups with two or more phase detection pixels covered by a single microlens. Each phase detection pixel may have an asymmetric angular response to incident light. Phase detection pixels may be covered by diffractive lenses. A diffractive lens may cover a phase detection pixel pair to improve angular separation between the pixels. A diffractive lens may partially cover a phase detection pixel in a phase detection pixel pair to shift the angular response and account for an off-axis chief ray angle of the phase detection pixel pair.

Abstract: A semiconductor wafer has a plurality of non-rectangular semiconductor die with an image sensor region. The non-rectangular semiconductor die has a circular, elliptical, and shape with non-linear side edges form factor. The semiconductor wafer is singulated with plasma etching to separate the non-rectangular semiconductor die. A curved surface is formed in the image sensor region of the non-rectangular semiconductor die. The non-rectangular form factor effectively removes a portion of the base substrate material in a peripheral region of the semiconductor die to reduce stress concentration areas and neutralize buckling in the curved surface of the image sensor region. A plurality of openings or perforations can be formed in a peripheral region of a rectangular or non-rectangular semiconductor die to reduce stress concentration areas and neutralize buckling. A second semiconductor die can be formed in an area of the semiconductor wafer between the non-rectangular semiconductor die.

Abstract: Various embodiments of the present technology may comprise a method and apparatus for a biosensor. The biosensor comprises a vertical flow channel that extends through a photodiode, and wherein the photodiode is lateral to the channel's vertical sidewall.

Abstract: A semiconductor device may include an array of single-photon avalanche diode pixels. The single-photon avalanche diode (SPAD) pixels may be capable of detecting a single photon. To improve dynamic range, a light attenuating layer may be incorporated into the semiconductor device. The light attenuating layer may selectively attenuate the incident light that passes to select SPAD pixels according to a known ratio. Processing circuitry in the system can determine that, for every photon detected by a SPAD pixel receiving attenuated light, more incident photons were actually received in accordance with the ratio. In this way, high photon fluxes may accurately be detected. SPAD pixels covered by a light attenuating element with low attenuation may be sensitive to low incident light levels. SPAD pixels covered by a light attenuating element with high attenuation may be sensitive to high incident light levels.

Abstract: An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by square toroidal microlenses to direct light incident on the pixels onto photosensitive regions of the pixels. The square toroidal microlenses may be formed as first and second sets of microlenses aligned with every other SPAD pixel and may allow the square toroidal microlenses to be formed without gaps between adjacent lenses. Additionally or alternatively, a central portion of each square toroidal microlenses may be filled by a fill-in microlens. Together, the square toroidal microlenses and the fill-in microlenses may form convex microlenses over each SPAD pixel. The fill-in microlenses may be formed from material having a higher index of refraction than material that forms the square toroidal microlenses.

Abstract: A semiconductor device may include an array of single-photon avalanche diode pixels. The single-photon avalanche diode (SPAD) pixels may be capable of detecting a single photon. To improve dynamic range, a light attenuating layer may be incorporated into the semiconductor device. The light attenuating layer may selectively attenuate the incident light that passes to select SPAD pixels according to a known ratio. Processing circuitry in the system can determine that, for every photon detected by a SPAD pixel receiving attenuated light, more incident photons were actually received in accordance with the ratio. In this way, high photon fluxes may accurately be detected. SPAD pixels covered by a light attenuating element with low attenuation may be sensitive to low incident light levels. SPAD pixels covered by a light attenuating element with high attenuation may be sensitive to high incident light levels.

Abstract: Three-dimensional structures may be formed on a substrate using a propellant that may decompose to form a gaseous byproduct. At least one overlying shell layer may deform due to volumes of gas between the substrate and the shell layer formed by the gaseous byproduct, thereby forming the three-dimensional structures. Multiple layers of propellant and shell layers may be stacked to multi-layered, three-dimensional structures. Propellant with different concentrations and shell layers with different thicknesses and materials may be used to control the shapes formed when the propellant is decomposed. Alternatively, porous layers may be deposited on a substrate and heated to expand volumes of gas between the substrate and the porous layers, thereby forming three-dimensional structures. The three-dimensional structures may be formed as microlenses in imaging sensor pixels, as it may be desired to form an array of microlenses that vary in size, shape, or curvature across one or more pixels.

Abstract: An imaging system may include an image sensor, a lens, and layers with reflective properties, such as an infrared cut-off filter, between the lens and the image sensor. The lens may focus light from an object in a scene onto the image sensor. Some of the light directed onto the image sensor may form a first image on the image sensor. Other portions of the light directed onto the image sensor may reflect off of the image sensor and back towards the layers with reflective properties. These layers may reflect the light back onto the image sensor, forming a second image that is shifted relative to the first image. Depth mapping circuitry may compare the first and second images to determine the distance between the imaging system and the object in the scene.

Abstract: Color filters may affect imaging performance attributes such as low light sensitivity, color accuracy, and modulation transfer function (MTF). In an image pixel array, these factors are influenced by both the spectral absorption and pattern of the color filter elements. Different portions of an image sensor may prioritize different imaging performance attributes. Accordingly, in certain applications it may be beneficial for color filter characteristics to vary across an image sensor. Different color filters of the same color may have different structures to optimize imaging performance across the image sensor.

Abstract: An image sensor may include phase detection pixels that gather phase detection data. The phase detection pixels may be formed in phase detection pixel groups with two or more phase detection pixels covered by a single microlens. Each phase detection pixel may have an asymmetric angular response to incident light. Phase detection pixels may be covered by diffractive lenses. A diffractive lens may cover a phase detection pixel pair to improve angular separation between the pixels. A diffractive lens may partially cover a phase detection pixel in a phase detection pixel pair to shift the angular response and account for an off-axis chief ray angle of the phase detection pixel pair.

Abstract: An image sensor may include high dynamic range imaging pixels having an inner sub-pixel surrounded by an outer sub-pixel. To steer light away from the inner sub-pixel and towards the outer sub-pixel, the high dynamic range imaging pixels may be covered by a toroidal microlens. To mitigate cross-talk caused by high-angled incident light, various microlens arrangements may be used. A toroidal microlens may have planar portions on its outer perimeter. A toroidal microlens may be covered by four additional microlenses, each additional microlens positioned in a respective corner of the pixel. Each pixel may be covered by four microlenses in a 2×2 arrangement, with an opening formed by the space between the four microlenses overlapping the inner sub-pixel.

Abstract: An image sensor may include pixels having nested sub-pixels. A pixel with nested sub-pixels may include an inner sub-pixel that has either an elliptical or a rectangular light collecting area. The inner sub-pixel may be formed in a substrate and may be immediately surrounded by a sub-pixel group that includes one or more sub-pixels. The inner sub-pixel may have a light collecting area at a surface that is less sensitive than the light collecting area of the one or more outer sub-pixel groups. Microlenses may be formed over the nested sub-pixels, to direct light away from the inner sub-pixel group to the outer sub-pixel groups in nested sub-pixels. A color filter of a single color may be formed over the nested sub-pixels. Hybrid color filters having a single color filter region over the inner sub-pixel and a portion of the one or more outer sub-pixel groups may also be used.

Abstract: An imaging system may include an image sensor, a lens, and layers with reflective properties, such as an infrared cut-off filter, between the lens and the image sensor. The lens may focus light from an object in a scene onto the image sensor. Some of the light directed onto the image sensor may form a first image on the image sensor. Other portions of the light directed onto the image sensor may reflect off of the image sensor and back towards the layers with reflective properties. These layers may reflect the light back onto the image sensor, forming a second image that is shifted relative to the first image. Depth mapping circuitry may compare the first and second images to determine the distance between the imaging system and the object in the scene.

Abstract: Various embodiments of the present technology may comprise a method and apparatus for a biosensor. The biosensor comprises a vertical flow channel that extends through a photodiode, and wherein the photodiode is lateral to the channel's vertical sidewall.