Abstract: CMOS image sensor with LED flickering reduction and low color cross-talk are disclosed. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of large subpixels (LPDs) and at least one small subpixel (SPD). A plurality of color filters are disposed over individual subpixels. Each individual SPD is laterally adjacent to at least one other SPD.

Abstract: Image sensors, isolation structures, and techniques of fabrication are provided. An image sensor includes a source of electromagnetic radiation disposed on a substrate, a pixel array disposed on the substrate and thermally coupled with source of electromagnetic radiation, and an isolation structure disposed on the substrate between the source of electromagnetic radiation and the pixel array. The isolation structure can define a first reflective surface oriented on a first bias relative to a lateral axis of the pixel array and a second reflective surface oriented on a second bias relative to the lateral axis. The isolation structure can be configured to attenuate residual electromagnetic radiation reaching a proximal region of the pixel array by pairing a first reflection and a second reflection of the electromagnetic radiation by the first reflective surface and the second reflective surface.

Abstract: An image sensor includes a substrate. An array of photodiodes is disposed in the substrate. A plurality of spacers is arranged in a spacer pattern. At least one spacer of the plurality of spacers has an aspect ratio of 18:1 or greater. A buffer layer is disposed between the substrate and the spacer pattern. An array of color filters is disposed in the spacer pattern.

Abstract: A flicker-mitigating pixel-array substrate includes a semiconductor substrate and a metal annulus. The semiconductor substrate includes a small-photodiode region. A back surface of the semiconductor substrate forms a trench surrounding the small-photodiode region in a cross-sectional plane parallel to a back-surface region of the back surface above the small-photodiode region. The metal annulus (i) at least partially fills the trench, (ii) surrounds the small-photodiode region in the cross-sectional plane, and (iii) extends above the back surface. A method for fabricating a flicker-mitigating pixel-array substrate includes forming a metal layer (i) in a trench that surrounds the small-photodiode region in a cross-sectional plane parallel to a back-surface region of the back surface above the small-photodiode region and (ii) on the back-surface region. The method also includes decreasing a thickness of an above-diode section of the metal layer located above the back-surface region.

Abstract: A reduced cross-talk pixel-array substrate includes a semiconductor substrate, a buffer layer, a metal annulus, and an attenuation layer. The semiconductor substrate includes a first photodiode region. A back surface of the semiconductor substrate forms a trench surrounding the first photodiode region in a cross-sectional plane parallel to a first back-surface region of the back surface above the first photodiode region. The buffer layer is on the back surface and has a feature located above the first photodiode region with the feature being one of a recess and an aperture. The metal annulus is on the buffer layer and covers the trench. The attenuation layer is above the first photodiode region.

Abstract: A backside-illuminated image sensor includes arrayed photodiodes separated by isolation structures, and interlayer dielectric between first layer of metal interconnect and substrate. The image sensor has barrier metal walls in the interlayer dielectric between isolation structures and first layer interconnect, the barrier metal walls aligned with the isolation structures and disposed between the isolation structures and first layer interconnect. The barrier metal wall deflects light passing through photodiodes of the sensor that would otherwise be reflected by interconnect into different photodiodes.

Abstract: A pixel cell includes a plurality of subpixels to generate image charge in response to incident light. The subpixels include an inner subpixel laterally surrounded by outer subpixels. A first plurality of transfer gates disposed proximate to the inner subpixel and a first grouping of outer subpixels. A first floating diffusion is coupled to receive the image charge from the first grouping of outer subpixels through a first plurality of transfer gates. A second plurality of transfer gates disposed proximate to the inner subpixel and the second grouping of outer subpixels. A second floating diffusion disposed in the semiconductor material and coupled to receive the image charge from each one of the second grouping of outer subpixels through the second plurality of transfer gates. The image charge in the inner subpixel is received by the first, second, or both floating diffusions through respective transfer gates.

Abstract: CMOS image sensor with LED flickering reduction and low color cross-talk are disclosed. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of large subpixels (LPDs) and at least one small subpixel (SPD). A plurality of color filters are disposed over individual subpixels. Each individual SPD is laterally adjacent to at least one other SPD.

Abstract: CMOS image sensor with multiple sensitivities for high dynamic range imaging and LED flicker mitigation. In one embodiment, an image sensor includes a plurality of pixels arranged in rows and columns of a pixel array that is disposed in a semiconductor substrate. Each pixel includes a plurality of cells. A plurality of color filters is disposed over corresponding plurality of cells. The plurality of color filters corresponding to the plurality of cells of an individual pixel have more than one filtering strength for each color of the plurality of color filters.

Abstract: An image sensor comprises a first photodiode region and circuitry. The first photodiode region is disposed within a semiconductor substrate proximate to a first side of the semiconductor substrate to form a first pixel. The first photodiode region includes a first segment coupled to a second segment. The circuitry includes at least a first electrode associated with a first transistor. The first electrode is disposed, at least in part, between the first segment and the second segment of the first photodiode region such that the circuity is at least partially surrounded by the first photodiode region when viewed from the first side of the semiconductor substrate.

Abstract: A flicker-mitigating pixel-array substrate includes a semiconductor substrate and a metal annulus. The semiconductor substrate includes a small-photodiode region. A back surface of the semiconductor substrate forms a trench surrounding the small-photodiode region in a cross-sectional plane parallel to a back-surface region of the back surface above the small-photodiode region. The metal annulus (i) at least partially fills the trench, (ii) surrounds the small-photodiode region in the cross-sectional plane, and (iii) extends above the back surface. A method for fabricating a flicker-mitigating pixel-array substrate includes forming a metal layer (i) in a trench that surrounds the small-photodiode region in a cross-sectional plane parallel to a back-surface region of the back surface above the small-photodiode region and (ii) on the back-surface region. The method also includes decreasing a thickness of an above-diode section of the metal layer located above the back-surface region.

Abstract: Image sensors include a substrate material having a plurality of small photodiodes (SPDs) and a plurality of large photodiodes (LPDs) disposed therein. A plurality of pixel isolators is formed in the substrate material, each pixel isolator being disposed between one of the SPDs and one of the LPDs. A passivation layer is disposed on the substrate material and a buffer layer is disposed on the passivation layer. A plurality of first metal elements is disposed in the buffer layer, each first metal element being disposed over one of the pixel isolators, and a plurality of second metal elements is disposed over the plurality of first metal elements.

Abstract: An image sensor includes a substrate. An array of photodiodes is disposed in the substrate. A plurality of spacers is arranged in a spacer pattern. At least one spacer of the plurality of spacers has an aspect ratio of 18:1 or greater. A buffer layer is disposed between the substrate and the spacer pattern. An array of color filters is disposed in the spacer pattern.

Abstract: An image sensor includes a substrate. An array of photodiodes is disposed in the substrate. A plurality of spacers is arranged in a spacer pattern. At least one spacer of the plurality of spacers has an aspect ratio of 18:1 or greater. A buffer layer is disposed between the substrate and the spacer pattern. An array of color filters is disposed in the spacer pattern.

Abstract: A pixel cell includes a first photodiode, a second photodiode, a first deep trench isolation region, a second deep trench isolation region, a buffer oxide layer, and a light attenuation layer. The attenuation layer partially encapsulates the first photodiode by extending laterally from the first deep trench isolation region to the second deep trench isolation region between the semiconductor material and the buffer oxide layer.

Abstract: An image sensor includes a substrate material. The substrate material includes a plurality of photodiodes disposed therein. The plurality of photodiodes includes a plurality of small photodiodes (SPDs) and a plurality of large photodiodes (LPDs) larger than the SPDs. An array of color filters is disposed over the substrate material. A buffer layer is disposed between the substrate material and the array of color filters. A metal pattern is disposed between the color filters in the array of color filters, and between the array of color filters and the buffer layer. An attenuation layer is disposed between the substrate material and the array of color filters. The attenuation layer is above and aligned with the plurality of SPDs and a portion of each of the plurality of LPDs. An edge of the attenuation layer is over one of the plurality of LPDs.

Abstract: A sensor includes a photodiode disposed in a semiconductor material to receive light and convert the light into charge, and a first floating diffusion coupled to the photodiode to receive the charge. A second floating diffusion is coupled to the photodiode to receive the charge, and a first transfer transistor is coupled to transfer the charge from the photodiode into the first floating diffusion. A second transfer transistor is coupled to transfer the charge from the photodiode into the second floating diffusion, and an inductor is coupled between a first gate terminal of the first transfer transistor and a second gate terminal of the second transfer transistor. The inductor, the first gate terminal, and the second gate terminal form a resonant circuit.

Abstract: A pixel cell includes a plurality of subpixels to generate image charge in response to incident light. The subpixels include an inner subpixel laterally surrounded by outer subpixels. A first plurality of transfer gates disposed proximate to the inner subpixel and a first grouping of outer subpixels. A first floating diffusion is coupled to receive the image charge from the first grouping of outer subpixels through a first plurality of transfer gates. A second plurality of transfer gates disposed proximate to the inner subpixel and the second grouping of outer subpixels. A second floating diffusion disposed in the semiconductor material and coupled to receive the image charge from each one of the second grouping of outer subpixels through the second plurality of transfer gates. The image charge in the inner subpixel is received by the first, second, or both floating diffusions through respective transfer gates.

Abstract: Image sensors include a substrate material having a plurality of small photodiodes (SPDs) and a plurality of large photodiodes (LPDs) disposed therein. A plurality of pixel isolators is formed in the substrate material, each pixel isolator being disposed between one of the SPDs and one of the LPDs. A passivation layer is disposed on the substrate material and a buffer layer is disposed on the passivation layer. A plurality of first metal elements is disposed in the buffer layer, each first metal element being disposed over one of the pixel isolators, and a plurality of second metal elements is disposed over the plurality of first metal elements.

Abstract: A pixel cell includes a first photodiode, a second photodiode, a first deep trench isolation region, a second deep trench isolation region, a buffer oxide layer, and a light attenuation layer. The attenuation layer partially encapsulates the first photodiode by extending laterally from the first deep trench isolation region to the second deep trench isolation region between the semiconductor material and the buffer oxide layer.