Abstract:
A photodetector includes a first doped region disposed in a semiconductor material and a second doped region disposed in the semiconductor material. The second doped region is electrically coupled to the first doped region, and the second doped region is of an opposite majority charge carrier type as the first doped region. The photodetector also includes a quantum dot layer disposed in a trench in the semiconductor material, and the quantum dot layer is electrically coupled to the second doped region. A transfer gate is disposed to permit charge transfer from the second doped region to a floating diffusion.
Abstract:
An image sensor includes a substrate, a first set of sensor pixels formed on the substrate, and a second set of sensor pixels formed on the substrate. The sensor pixels of the first set are arranged in rows and columns and are configured to detect light within a first range of wavelengths (e.g., white light). The sensor pixels of the second set are arranged in rows and columns and are each configured to detect light within one of a set of ranges of wavelengths (e.g., red, green, and blue). Each range of wavelengths of the set of ranges of wavelengths is a subrange of said first range of wavelengths, and each pixel of the second set of pixels is smaller than each pixel of the first set of pixels.
Abstract:
An image sensor for detecting light-emitting diode (LED) without flickering includes a pixel array with pixels. Each pixel including subpixels including a first and a second subpixel, dual floating diffusion (DFD) transistor, and a capacitor coupled to the DFD transistor. First subpixel includes a first photosensitive element to acquire a first image charge, and a first transfer gate transistor to selectively transfer the first image charge from the first photosensitive element to a first floating diffusion (FD) node. Second subpixel includes a second photosensitive element to acquire a second image charge, and a second transfer gate transistor to selectively transfer the second image charge from the second photosensitive element to a second FD node. DFD transistor coupled to the first and the second FD nodes. Other embodiments are also described.
Abstract:
An image sensor includes a pixel array with a plurality of pixels arranged in a semiconductor layer. A color filter array including a plurality of groupings of filters is disposed over the pixel array. Each filter is optically coupled to a corresponding one of the plurality of pixels. Each one of the plurality of groupings of filters includes a first, a second, a third, and a fourth filter having a first, a second, the second, and a third color, respectively. A metal layer is disposed over the pixel array and is patterned to include a metal mesh having mesh openings with a size and pitch to block incident light having a fourth color from reaching the corresponding pixel. The metal layer is patterned to include openings without the metal mesh to allow the incident light to reach the other pixels.
Abstract:
A method of image sensor fabrication includes forming a layer of dielectric material, a layer of gate material, and a layer of hard mask material. The layer of dielectric material is disposed between the layer of gate material and a semiconductor material, and the layer of gate material is disposed between the layer of hard mask material and the layer of dielectric material. The method also includes etching the layer of hard mask material and layer of gate material, and etching forms a transfer gate from the layer of gate material. An encapsulation material is deposited proximate to a surface of the semiconductor material. Trenches are etched in the encapsulation material. A first trench extends through the encapsulation material and the layer of dielectric material, and a second trench extends through the encapsulation material and the layer of hard mask material.
Abstract:
An image sensor includes photodiodes arranged in semiconductor material. Each of the photodiodes is identically sized and is fabricated in the semiconductor material with identical semiconductor processing conditions. The photodiodes are organized into virtual large-small groupings including a first photodiode and a second photodiode. Microlenses are disposed over the semiconductor material with each of microlenses disposed over a respective photodiode. A first microlens is disposed over the first photodiode, and a second microlens is disposed over the second photodiode. A mask is disposed between the first microlens and the first photodiode. The mask includes an opening through which a first portion of incident light directed through the first microlens is directed to the first photodiode. A second portion of the incident light directed through the first microlens is blocked by the mask from reaching the first photodiode. There is no mask between the second microlens and the second photodiode.
Abstract:
A back side illuminated image sensor includes a pixel array including semiconductor material, and image sensor circuitry disposed on a front side of the semiconductor material to control operation of the pixel array. A first pixel includes a first doped region disposed proximate to a back side of the semiconductor material and extends into the semiconductor material a first depth to reach the image sensor circuitry. A second pixel with a second doped region is disposed proximate to the back side of the semiconductor material and extends into the semiconductor material a second depth which is less than the first depth. A third doped region is disposed between the second doped region and the image sensor circuitry front side of the semiconductor material. The third doped region is electrically isolated from the first doped region and the second doped region.
Abstract:
A method of forming microlenses for an image sensor having at least one large-area pixel and at least one small-area pixel is disclosed. The method includes forming a uniform layer of microlens material on a light incident side of the image sensor over the large-area pixel and over the small-area pixel. The method also includes forming the layer of microlens material into a first block disposed over the large-area pixel and into a second block disposed over the small-area pixel. A void is also formed in the second block to reduce a volume of microlens material included in the second block. The first and second blocks are then reflowed to form a respective first microlens and second microlens. The first microlens has substantially the same effective focal length as the second microlens.
Abstract:
An image sensor includes a plurality of photosensitive devices arranged in a semiconductor substrate. A planar layer is disposed over the plurality of photosensitive devices in the semiconductor substrate. A plurality of first microlenses comprised of a lens material is arranged in first lens regions on the planar layer. A plurality of lens barriers comprised of the lens material is arranged on the planar layer to provide boundaries that define second lens regions on the planar layer. A plurality of second microlenses comprised of the lens material is formed within the boundaries provided by the plurality of lens barriers that define the second lens regions on the planar layer. The plurality of lens barriers are integrated with respective second microlenses after a reflow process of the plurality of second microlenses.
Abstract:
An image sensor pixel for use in a high dynamic range image sensor includes a first photodiode, a plurality of photodiodes, a shared floating diffusion region, a first transfer gate, and a second transfer gate. The first photodiode is disposed in a semiconductor material. The first photodiode has a first light exposure area and a first doping concentration. The plurality of photodiodes is also disposed in the semiconductor material. Each photodiode in the plurality of photodiodes has the first light exposure area and the first doping concentration. The first transfer gate is coupled to transfer first image charge from the first photodiode to the shared floating diffusion region. The second transfer gate is coupled to transfer distributed image charge from each photodiode in the plurality of photodiodes to the shared floating diffusion region.