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. To mitigate crosstalk, an isolation structure may be formed in a ring around the SPAD. The isolation structure may be a hybrid isolation structure with both a metal filler that absorbs light and a low-index filler that reflects light. The isolation structure may be formed as a single trench or may include a backside deep trench isolation portion and a front side deep trench isolation portion. The isolation structure may also include a color filtering material.

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. To mitigate crosstalk, multiple rings of isolation structures may be formed around the SPAD. An outer deep trench isolation structure may include a metal filler such as tungsten and may be configured to absorb light. The outer deep trench isolation structure therefore prevents crosstalk between adjacent SPADs. Additionally, one or more inner deep trench isolation structures may be included. The inner deep trench isolation structures may include a low-index filler to reflect light and keep incident light in the active area of the SPAD.

Abstract: An imaging device may include a plurality of single-photon avalanche diode (SPAD) pixels. The SPAD pixels may be overlapped by microlenses to direct light incident on the pixels onto photosensitive regions of the pixels and a containment grid with openings that surround each of the microlenses. During formation of the microlenses, the containment grid may prevent microlens material for adjacent SPAD pixels from merging. To ensure separation between the microlenses, the containment grid may be formed from material phobic to microlens material, or phobic material may be added over the containment grid material. Additionally, the containment grid may be formed from material that can absorb stray or off-angle light so that it does not reach the associated SPAD pixel, thereby reducing crosstalk during operation of the SPAD pixels.

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 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 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 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: Various embodiments of the present technology may comprise a method and apparatus for an image sensor with a thermal equalizer for distributing heat. The method and apparatus may comprise a thermal equalizer disposed between a sensor die and a circuit die to prevent uneven heating of the pixels in the sensor die. The method and apparatus may comprise a thermal equalizer integrated within the circuit die.

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: Global shutter imaging pixels may include a charge storage region that receives charge from a respective photodiode. Global shutter imaging pixels may be formed as frontside illuminated imaging pixels or backside illuminated imaging pixels. Shielding charge storage regions from incident light may be important for image sensor performance. To shield charge storage regions in backside illuminated global shutter imaging pixels, shielding structures may be included over the charge storage region. The shielding structures may include backside trench isolation structures, a metal layer formed in a backside trench between backside trench isolation structures, and frontside deep trench isolation structures. The metal layer may have angled portions that reflect light towards the photodiodes.

Abstract: An image sensor package may include a semiconductor wafer having a pixel array, a color filter array (CFA) formed over the pixel array, and one or more lenses formed over the CFA. A light block layer may couple over the semiconductor wafer around a perimeter of the lenses and an encapsulation layer may be coupled around the perimeter of the lenses and over the light block layer. The light block layer may form an opening providing access to the lenses. A mold compound layer may be coupled over the encapsulation layer and the light block layer. A temporary protection layer may be used to protect the one or more lenses from contamination during application of the mold compound and/or during processes occurring outside of a cleanroom environment.

Abstract: Implementations of image sensors may include a silicon layer having a first side and a second side opposite the first side, an opening extending into the silicon layer from the first side of the silicon layer toward the second side, a via extending into the silicon layer from the second side of the silicon layer, and a conductive pad within the opening. The conductive pad may be coupled to the via. The opening may include a fill material. At least a portion of the fill material may form a plane that is substantially parallel with the first side of the silicon layer. The conductive pad may be exposed through an opening in the fill material.

Abstract: Implementations of image sensors may include a silicon layer having a first side and a second side opposite the first side, an opening extending into the silicon layer from the first side of the silicon layer toward the second side, a via extending into the silicon layer from the second side of the silicon layer, and a conductive pad within the opening. The conductive pad may be coupled to the via. The opening may include a fill material. At least a portion of the fill material may form a plane that is substantially parallel with the first side of the silicon layer. The conductive pad may be exposed through an opening in the fill material.

Abstract: An image sensor package may include a semiconductor wafer having a pixel array, a color filter array (CFA) formed over the pixel array, and one or more lenses formed over the CFA. A light block layer may couple over the semiconductor wafer around a perimeter of the lenses and an encapsulation layer may be coupled around the perimeter of the lenses and over the light block layer. The light block layer may form an opening providing access to the lenses. A mold compound layer may be coupled over the encapsulation layer and the light block layer. A temporary protection layer may be used to protect the one or more lenses from contamination during application of the mold compound and/or during processes occurring outside of a cleanroom environment.

Abstract: An image sensor package may include a semiconductor wafer having a pixel array, a color filter array (CFA) formed over the pixel array, and one or more lenses formed over the CFA. A light block layer may couple over the semiconductor wafer around a perimeter of the lenses and an encapsulation layer may be coupled around the perimeter of the lenses and over the light block layer. The light block layer may form an opening providing access to the lenses. A mold compound layer may be coupled over the encapsulation layer and the light block layer. A temporary protection layer may be used to protect the one or more lenses from contamination during application of the mold compound and/or during processes occurring outside of a cleanroom environment.

Abstract: Multi-photodiode image pixels may include sub-pixels with differing light sensitivities. Microlenses may be formed over the multi-photodiode image pixels so that light sensitivity of sub-pixels in an outer group of sub-pixels is enhanced. To prevent high angle light incident upon one of the sub-pixels of the image pixel from generating charges in a photosensitive region of another sub-pixel of the image pixel, intra-pixel isolation structures may be formed. Intra-pixel isolation structures may surround, and in some embodiments, overlap the light collecting region of an inner photodiode. When the intra-pixel isolation structures have a different index of refraction than light filtering material formed adjacent to the isolation structures, high angle light incident upon the isolation structures may be reflected back into the sub-pixel it was initially incident upon.

Abstract: Multi-photodiode image pixels may include sub-pixels with differing light sensitivities. Microlenses may be formed over the multi-photodiode image pixels so that light sensitivity of sub-pixels in an outer group of sub-pixels is enhanced. To prevent high angle light incident upon one of the sub-pixels of the image pixel from generating charges in a photosensitive region of another sub-pixel of the image pixel, intra-pixel isolation structures may be formed. Intra-pixel isolation structures may surround, and in some embodiments, overlap the light collecting region of an inner photodiode. When the intra-pixel isolation structures have a different index of refraction than light filtering material formed adjacent to the isolation structures, high angle light incident upon the isolation structures may be reflected back into the sub-pixel it was initially incident upon.

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.