A method of fabricating a semiconductor structure includes disposing a metal catalyst on a surface of a semiconductor. Thereafter, metal assisted chemical etching is performed, including holding the semiconductor immersed in an etchant solution and catalyzing an etching chemical reaction between the etchant solution and the semiconductor using the metal catalyst to etch the semiconductor to form a channel in the semiconductor. During at least a portion of the metal assisted chemical etching the semiconductor is held immersed in the etchant solution with a surface normal of the surface of the semiconductor at a non-zero angle respective to gravity. In some examples, an orientation of the semiconductor is changed during the metal assisted chemical etching to form the channel in the semiconductor with at least one bend or curved portion.

In-pixel separation structures may divide photodiodes of a pixel array into multiple regions. As a result, a lens of an image sensor device may be focused by using combining signals associated with different portions of the photodiodes. As a result, the lens may be focused faster and with fewer pixels of the pixel array, which conserves power, processing resources, and raw materials.

Some implementations described herein include a complementary metal oxide semiconductor image sensor device and techniques to form the complementary metal oxide semiconductor image sensor device. The complementary metal oxide semiconductor image sensor device includes a includes a first array of photodiodes stacked over a second array of photodiodes. A polarization structure is between the first array of photodiodes and the second array of photodiodes. Signaling generated by the first array of photodiodes (e.g., signaling corresponding to unpolarized light waves) may be multiplexed with signaling generated by the second array of photodiodes (e.g., signaling corresponding to polarized light waves). The complementary metal oxide semiconductor image sensor device further includes a filter structure that filters visible light waves and near infrared light waves amongst the first array of photodiodes and the second array of photodiodes.

An image sensor comprises at least two vertically stacked photo-sensitive devices wherein each respective photo-sensitive device comprises a stack of a top electrode, a first charge transport layer and an active layer. Each respective stack generates electrical charges in response to a corresponding predefined range of wavelengths of light incident on the image sensor. Each photo-sensitive device further comprises a second charge transport layer having a first portion, vertically aligned underneath the active layer, and a second portion, transfer region, protruding laterally to extend beyond the active layer. A dielectric layer separates the first portion from a bottom electrode providing a voltage for depleting the first portion, and the transfer region from a transfer gate providing a voltage for transferring the generated electrical charge to a floating electrical connection, shared by all stacked photo-sensitive devices. The floating electrical connection couples to a read-out-circuitry.

An electronic device including a substrate, a silicon transistor disposed on the substrate, an oxide transistor disposed on the substrate and electrically connected to the silicon transistor, and a sensor configured to receive a light and output a signal. The silicon transistor and the oxide transistor are operated corresponding to the signal.

Various embodiments of the present disclosure are directed towards a method for forming a pixel sensor. The method comprises forming a photodetector in a substrate. The substrate is patterned to define an opening above the photodetector. A gate electrode is formed within the opening, where the gate electrode has a top conductive body overlying a bottom conductive body. A first segment of a sidewall of the top conductive body contacts the bottom conductive body. A floating diffusion node is formed in the substrate laterally adjacent to the gate electrode. A second segment of the sidewall of the top conductive body overlies the floating diffusion node.

The present disclosure, in some embodiments, relates to an image sensor integrated chip. The image sensor integrated chip includes a semiconductor substrate having sidewalls that form one or more trenches. The one or more trenches are disposed along opposing sides of a photodiode and vertically extend from an upper surface of the semiconductor substrate to within the semiconductor substrate. A doped region is arranged along the upper surface of the semiconductor substrate and along opposing sides of the photodiode. A first dielectric lines the sidewalls of the semiconductor substrate and the upper surface of the semiconductor substrate. A second dielectric lines sidewalls and an upper surface of the first dielectric. The doped region has a width laterally between a side of the photodiode and a side of the first dielectric. The width of the doped region varies at different heights along the side of the photodiode.

The present disclosure relates to an image sensor having a photodiode surrounded by a back-side deep trench isolation (BDTI) structure, and an associated method of formation. In some embodiments, a plurality of pixel regions is disposed within an image sensing die and respectively comprises a photodiode configured to convert radiation into an electrical signal. The photodiode comprises a photodiode doping column with a first doping type surrounded by a photodiode doping layer with a second doping type that is different than the first doping type. A BDTI structure is disposed between adjacent pixel regions and extending from the back-side of the image sensor die to a position within the photodiode doping layer. The BDTI structure comprises a doped liner with the second doping type and a dielectric fill layer. The doped liner lines a sidewall surface of the dielectric fill layer.

An image sensor includes a substrate including a first surface and a second surface facing the first surface, a first photodiode located in a first region of the substrate and generating photocharges from light incident on the first region, a second photodiode located in a second region of the substrate and generating photocharges from light incident on the second region, and an isolation structure defining the first region in which the first photodiode is located and the second region in which the second photodiode is located, and extending between the first photodiode and the second photodiode. An area of the second region is smaller than an area of the first region, a first end of the isolation structure is coplanar with the second surface, and the isolation structure extends in a vertical direction from the second surface of the substrate toward the first surface of the substrate.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for eye gesture recognition. In one aspect, a method includes obtaining an electrical signal that represents a measurement, by a photodetector, of an optical signal reflected from an eye and determining a depth map of the eye based on phase differences between the electrical signal generated by the photodetector and a reference signal. Further, the method includes determining gaze information that represents a gaze of the eye based on the depth map and providing output data representing the gaze information.