Abstract: An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. The light scattering structures may include a low-index material formed in trenches in the semiconductor substrate. One or more microlenses may focus light onto the semiconductor substrate. Areas of the semiconductor substrate that receive more light from the microlenses may have a higher density of light scattering structures to optimize light scattering while mitigating dark current.

Abstract: Image pixels having IR sensors with reduced exposure to visible light. One example is an image sensor comprising: a photosensitive region; a lower optical filter above the photosensitive region, and the lower optical filter configured to filter visible light and to pass infrared light; and an upper optical filter above the lower optical filter, and the upper optical filter configured to filter visible light and to pass infrared light.

Abstract: An imaging device may include single-photon avalanche diodes (SPADs). Each SPAD may be overlapped by multiple microlenses. The microlenses over each SPAD may include first microlenses having a first size over a central portion of the SPAD and second microlenses having a second size that is greater than the first size over a peripheral area of the SPAD. The second microlenses may be spherical microlenses or cylindrical microlenses. The first microlenses may be aligned with underlying light scattering structures to improve the efficiency of the light scattering structures. The second microlenses may partially overlap isolation structures to direct light away from the isolation structures and towards the SPAD.

Abstract: An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. The light scattering structures may include a low-index material formed in trenches in the semiconductor substrate. One or more microlenses may focus light onto the semiconductor substrate. Areas of the semiconductor substrate that receive more light from the microlenses may have a higher density of light scattering structures to optimize light scattering while mitigating dark current.

Abstract: An imaging device may include single-photon avalanche diodes (SPADs). To improve the sensitivity and signal-to-noise ratio of the SPADs, light scattering structures may be formed in the semiconductor substrate to increase the path length of incident light through the semiconductor substrate. The light scattering structures may include a low-index material formed in trenches in the semiconductor substrate. One or more microlenses may focus light onto the semiconductor substrate. Areas of the semiconductor substrate that receive more light from the microlenses may have a higher density of light scattering structures to optimize light scattering while mitigating dark current.

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: An imaging system may include an image sensor with phase detection pixel groups for depth sensing or automatic focusing operations. Each phase detection pixel group may have two or more photosensitive regions covered by a single microlens so that each photosensitive region has an asymmetric angular response. The image sensor may be sensitive to both near-infrared (NIR) and visible light. Each phase detection pixel group may be designed to include light-scattering structures that increase NIR sensitivity while minimizing disruptions of phase detection and visible light performance. Deep trench isolation may be formed between adjacent photosensitive areas within the phase detection pixel group. The light-scattering structures may have a non-uniform distribution to minimize disruptions of phase detection performance.

Abstract: An imaging system may include an image sensor with phase detection pixel groups for depth sensing or automatic focusing operations. Each phase detection pixel group may have two or more photosensitive regions covered by a single microlens so that each photosensitive region has an asymmetric angular response. The image sensor may be sensitive to both near-infrared (NIR) and visible light. Each phase detection pixel group may be designed to include light-scattering structures that increase NIR sensitivity while minimizing disruptions of phase detection and visible light performance. Deep trench isolation may be formed between adjacent photosensitive areas within the phase detection pixel group. The light-scattering structures may have a non-uniform distribution to minimize disruptions of phase detection performance.

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: 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: A method for forming curved image sensors may include applying positive pressure to the face of an image sensor, forcing the image sensor to adhere the curved surface of a substrate. The pressure may be applied to the face of the image sensor in a variety of ways, including using pneumatic pressure, hydraulic pressure, or pressure from an elastic or inelastic solid. Processing may occur on either a single image sensor die or an image sensor wafer. When an image sensor wafer is processed, a substrate may be used that has a number of cavities defined by respective curved surfaces with each cavity corresponding to a respective image sensor. When pressure is applied to the image sensor, the image sensor may deform until the curvature of the image sensor matches the curvature of the curved surface of the underlying substrate.

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: An image sensor may include a pixel array with high dynamic range functionality and phase detection pixels. The phase detection pixels may be arranged in phase detection pixel groups. Each phase detection pixel group may include three adjacent pixels arranged consecutively in a line. A single microlens may cover all three pixels in the phase detection pixel group, or two microlenses may combine to cover the three pixels in the phase detection pixel group. The edge pixels in each phase detection pixel group may have the same integration time and the same color. The middle pixel in each phase detection pixel group may have the same or different color as the edge pixels, and the same or different integration time as the edge pixels. Phase detection pixel groups may also be formed from two pixels that each are 1.5 times the size of neighboring pixels.

Abstract: An image sensor may include a pixel array with high dynamic range functionality and phase detection pixels. The phase detection pixels may be arranged in phase detection pixel groups. Each phase detection pixel group may include three adjacent pixels arranged consecutively in a line. A single microlens may cover all three pixels in the phase detection pixel group, or two microlenses may combine to cover the three pixels in the phase detection pixel group. The edge pixels in each phase detection pixel group may have the same integration time and the same color. The middle pixel in each phase detection pixel group may have the same or different color as the edge pixels, and the same or different integration time as the edge pixels. Phase detection pixel groups may also be formed from two pixels that each are 1.5 times the size of neighboring pixels.

Abstract: A method for forming curved image sensors may include applying positive pressure to the face of an image sensor, forcing the image sensor to adhere the curved surface of a substrate. The pressure may be applied to the face of the image sensor in a variety of ways, including using pneumatic pressure, hydraulic pressure, or pressure from an elastic or inelastic solid. Processing may occur on either a single image sensor die or an image sensor wafer. When an image sensor wafer is processed, a substrate may be used that has a number of cavities defined by respective curved surfaces with each cavity corresponding to a respective image sensor. When pressure is applied to the image sensor, the image sensor may deform until the curvature of the image sensor matches the curvature of the curved surface of the underlying substrate.