An image sensor includes a substrate; a plurality of unit pixel regions in the substrate, each unit pixel region o including a floating diffusion region and a transfer gate electrode; and a microlens on the substrate. The transfer gate electrode includes a first connection part on a first surface of the substrate and a first extending part connected to the first connection part and extending from the first surface into the substrate. A third surface of the first extending part has a first angle with respect to the first surface of the substrate and a fourth surface of the first extending part has a second angle with respect to the first surface of the substrate. The fourth surface, the third surface, and the floating diffusion region are sequentially disposed in a direction parallel to the first surface of the substrate, and the first angle is greater than the second angle.

Disclosed herein are global shutter image sensors and methods of operating such image sensors. An image sensor includes a semiconductor wafer having a light receiving surface opposite an electrical connection surface; an oxide extending from the light receiving surface toward the electrical connection surface and at least partially surrounding a pixel region; a photodiode disposed within the pixel region; and a set of storage nodes disposed under the photodiode, between the photodiode and the electrical connection surface. The set of storage nodes comprises a first storage node and a second storage node. The storage nodes may be disposed vertically beneath the photodiode, or side by side.

An image sensor includes a semiconductor substrate having a first surface and a second surface opposite to the first surface, a transfer gate electrode provided on the first surface of the semiconductor substrate, readout circuit transistors spaced apart from the transfer gate electrode and provided on the first surface of the semiconductor substrate, and a photoelectric conversion layer provided in the semiconductor substrate at a side of the transfer gate electrode and including dopants of a first conductivity type. The photoelectric conversion layer includes a first region having a first thickness and a second region having a second thickness that is less than the first thickness. The second region overlaps with at least a portion of the readout circuit transistors in a direction perpendicular to the first surface of the semiconductor substrate.

Some embodiments are directed towards an image sensor device. A photodetector is disposed in a semiconductor substrate, and a transfer transistor is disposed over photodetector. The transfer transistor includes a transfer gate having a lateral portion extending over a frontside of the semiconductor substrate and a vertical portion extending to a first depth below the frontside of the semiconductor substrate. A gate dielectric separates the lateral portion and the vertical portion from the semiconductor substrate. A backside trench isolation structure extends from a backside of the semiconductor substrate to a second depth below the frontside of the semiconductor substrate. The backside trench isolation structure laterally surrounds the photodetector, and the second depth is less than the first depth such that a lowermost portion of the vertical portion of the transfer transistor has a vertical overlap with an uppermost portion of the backside trench isolation structure.

Depositing gallium nitride and carbon (GaN:C) (e.g., in the form of composite layers) when forming a gallium nitride drain of a transistor provides a buffer between the gallium nitride of the drain and silicon of a substrate in which the drain is formed. As a result, gaps and other defects caused by lattice mismatch are reduced, which improves electrical performance of the drain. Additionally, current leakage into the substrate is reduced, which further improves electrical performance of the drain. Additionally, or alternatively, implanting silicon in an aluminum nitride (AlN) liner for a gallium nitride drain reduces contact resistance at an interface between the gallium nitride and the silicon. As a result, electrical performance of the transistor is improved.

An image sensor is provided. The image sensor may include a substrate including first and second surfaces opposite to each other, a device isolation layer extending through the substrate and having a surface level with the second surface of the substrate, an active region comprising first and second pixel regions spaced apart and separated from each other by the device isolation layer, a photoelectric device located in the substrate and configured to convert light into electric charges, a microlens on the first surface, a first select transistor and a first source follower transistor in the first pixel region, a second source follower transistor in the second pixel region, a first node between the first select transistor and the first source follower transistor, on the first pixel region, and a second node on one side of the first select transistor on the first pixel region.

A depth pixel includes a first photodiode, a second photodiode and a common microlens. First and second taps are disposed at both sides of the first photodiode in a first horizontal direction to sample a photo charge stored in the first photodiode. The second photodiode is disposed at a side of the first photodiode in a second horizontal direction perpendicular to the first horizontal direction. Third and fourth taps are disposed at both sides of the second photodiode in the first horizontal direction to sample a photo charge stored in the second photodiode. The common microlens is disposed above or below the semiconductor substrate. The common microlens covers both of the first photodiode and the second photodiode to focus an incident light to the first photodiode and the second photodiode.

Image sensor systems are disclosed that include charge coupled device (CCD) pixels integrated with CMOS readout circuitry via separately bonded substrates. According to some embodiments, columns of image sensing pixels on a first substrate are arranged with overlapping gate structures to facilitate charge transfer between the pixels. At least one pixel is coupled to a first conductive pad that contacts (or is melded with) a second conductive pad from a second substrate bonded to the first substrate. The second substrate includes a readout circuit using one or more CMOS devices coupled to the second conductive pad to receive the accumulated charge from a given column of pixels. The resulting photodetector signal from the accumulated charge can be, for instance, amplified via a source follower component and ultimately read out to a column amplifier, and subjected to further processing and/or use in a given downstream system.

An image sensor includes a substrate having a plurality of unit pixels, a photoelectric device portion and a storage device portion disposed in the substrate and constituting the plurality of unit pixels, a device isolation structure disposed in the substrate and partitioning the plurality of unit pixels, and an overflow gate providing an overflow path between the photoelectric device portion and the storage device portion according to a certain voltage, wherein the device isolation structure is partially opened at a boundary between the photoelectric device portion and the storage device portion.

An imaging device that smoothly transfers electric charges from a photoelectric converter to a transfer destination is provided. This imaging device includes: a semiconductor layer; a photoelectric converter that generates electric charges corresponding to a received light amount; and a transfer section that includes a first trench gate and a second trench gate and transfers the electric charges from the photoelectric converter to a single transfer destination via the first trench gate and the second trench gate, the first trench gate and the second trench gate each extending from the front surface to the back surface of the semiconductor layer into the photoelectric converter. The first trench gate has a first length from the front surface to the photoelectric converter, and the second trench gate has a second length from the front surface to the photoelectric converter, the second length being shorter than the first length.