Semiconductor Components Industries, LLC

Byounghee Lee

Ulrich C Boettiger

Marc Allen Sulfridge

Swarnal Borthakur

Robert Michael Gravelle, Jr

Image sensor pixels and methods for constructing the same. The image sensor pixel includes a first photodetector, a second photodetector, a first spectral router, and a second spectral router. The first spectral router is positioned above the first photodetector and the second photodetector. The first spectral router is configured to direct incident light in a first subset of a first color wavelength range to the first photodetector and direct incident light in a second subset of the first color wavelength range to the second photodetector. The second spectral router is positioned above the first spectral router. The second spectral router is configured to direct the incident light in the first subset and the second subset of the first color wavelength range to the first spectral router. The second spectral router is configured to direct incident light in a second color wavelength range to one or more neighboring image sensor pixels.

Nanophotonic hyperspectral imaging

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.

Microlenses for semiconductor device with single-photon avalanche diode pixels

An image sensor may include an array of imaging pixels. Each imaging pixel may have a photosensitive area that is covered by a respective multipart diffractive lens to focus light onto the photosensitive area. The multipart diffractive lenses may have multiple portions with different indices of refraction. The portions of the diffractive lenses closer to the center of the diffractive lenses may have higher indices of refraction to focus light. Alternatively, the portions of the diffractive lenses closer to the center of the diffractive lenses may have lower indices of refraction to defocus light. The multipart diffractive lenses may have stacked layers with the same refractive indices but different widths.

Image sensors with multipart diffractive lenses

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.

Phase detection pixels with diffractive lenses

Image sensors may include plasmonic color filter elements that transmit specific wavelengths of incident light. Each plasmonic color filter element may be interposed between a respective microlens and photosensitive area. The plasmonic color filter elements may be formed from a metal layer such as gold, silver, platinum, aluminum, or copper and may have a pattern of openings in the metal layer that is designed to allow transmission of a certain type of light. To prevent cross-talk between adjacent pixels having plasmonic color filter elements, metal walls may be interposed between adjacent plasmonic color filter elements. The metal walls may extend above the upper surface of the metal layer that forms the plasmonic color filter elements. The metal walls may run around the periphery of each plasmonic color filter element.

Imaging pixels with plasmonic color filter elements

An image sensor may include an array of imaging pixels. Each imaging pixel may have a photosensitive area that is covered by a microlens and a diffractive lens that focuses light onto the photosensitive area. The diffractive lens may be interposed between the microlens and the photosensitive area. The diffractive lens may have a higher index of refraction than the surrounding materials. The diffractive lens may be formed as a portion of an anti-reflection coating. In some cases, multiple diffractive lenses may be formed over the imaging pixels. Focusing and defocusing diffractive lenses may be used to tune the response of the imaging pixels to incident light.

Image sensors with diffractive lenses for stray light control

An image sensor may include an array of imaging pixels. Each imaging pixel may have a photosensitive area that is covered by a respective diffractive lens to focus light onto the photosensitive area. The diffractive lenses may have a higher index of refraction than the surrounding materials. The diffractive lenses may be formed on an upper or lower surface of a planarization layer or may be embedded within the planarization layer. In some cases, multiple diffractive lenses may be formed over the imaging pixels. Some of the multiple diffractive lenses may have refractive indexes lower than the planarization layer such that the diffractive lenses defocus light. Focusing and defocusing diffractive lenses may be used to tune the response of the imaging pixels to incident light.

Image sensors with diffractive lenses

In order to increase angular response or otherwise customize the response of phase detection pixels to incident light, phase detection pixels may include optical structures. The optical structures may be formed between a microlens and at least first and second photodiodes to redirect incident light between the microlens and the photodiodes. The optical structures may include two or more layers with different indices of refraction. For example, a layer of silicon dioxide and a layer of silicon nitride may form a concave lens that increases the angular response of phase detection pixels. The optical structures may have any desired shape to customize the response of the photodiodes to incident light.

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Byounghee Lee