Abstract: A pixel-array substrate includes a semiconductor substrate with a pixel array, a back surface, and a front surface, and a guard ring formed of a doped semiconductor, enclosing the pixel array, and extending into the semiconductor substrate from the front surface, the back surface forming a trench extending into the semiconductor substrate, the trench overlapping the guard ring. A method for reducing leakage current into a pixel-array includes doping a semiconductor substrate to form a guard ring that extends into the semiconductor substrate from a front surface, encloses a pixel array, excludes a periphery region, and resists a flow of electric current, and forming, into a back surface of the semiconductor substrate, a trench that penetrates into the back surface and overlaps the guard ring, the guard ring and the trench configured to resist the flow of electric current between the pixel array and the periphery region.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by two micro-lenses, respectively. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array. A PDAF micro-lens is formed on the coating layer to cover the first image sensor pixels.

Abstract: A pixel-array substrate includes a semiconductor substrate with a pixel array, a back surface, and a front surface, and a guard ring formed of a doped semiconductor, enclosing the pixel array, and extending into the semiconductor substrate from the front surface, the back surface forming a trench extending into the semiconductor substrate, the trench overlapping the guard ring. A method for reducing leakage current into a pixel-array includes doping a semiconductor substrate to form a guard ring that extends into the semiconductor substrate from a front surface, encloses a pixel array, excludes a periphery region, and resists a flow of electric current, and forming, into a back surface of the semiconductor substrate, a trench that penetrates into the back surface and overlaps the guard ring, the guard ring and the trench configured to resist the flow of electric current between the pixel array and the periphery region.

Abstract: An image sensor includes one or more photodiodes disposed in a semiconductor material to receive image light and generate image charge, and a floating diffusion to receive the image charge from the one or more photodiodes. One or more transfer transistors is coupled to transfer image charge in the one or more photodiodes to the floating diffusion, and a source follower transistor is coupled to amplify the image charge in the floating diffusion. The source follower includes a gate electrode (coupled to the floating diffusion), source and drain electrodes, and an active region disposed in the semiconductor material between the source and drain electrodes. A dielectric material is disposed between the gate electrode and the active region and has a first thickness and a second thickness. The second thickness is greater than the first thickness, and the second thickness is disposed closer to the drain electrode than the first thickness.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by a shared micro-lens. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array to receive incident light.

Abstract: An image sensor pixel array comprises a center region and two parallel edge regions, wherein the center region is between the two parallel edge regions. The center region comprises a plurality of image pixels disposed along first sub-array of rows and columns, wherein each of the plurality of image pixels comprises a first micro-lens (ML) formed at an offset position above a first light receiving element as a countermeasure for shortening of exit pupil distance of the image pixel in the center region, and each of the two parallel edge regions comprises a plurality of phase detection auto-focus (PDAF) pixels disposed along second sub-array of rows and columns, wherein each of the plurality of PDAF pixels comprises a second micro-lens (ML) formed at an alignment position above a second light receiving element; and at least one of the PDAF pixels is located at a distance away from center of the edge region to receive incident light along an injection tilt angle.

Abstract: An image sensor pixel includes a photodiode disposed in a semiconductor material to generate image charge in response to light incident on a backside of the semiconductor material, and a pinning layer disposed in the semiconducting material and coupled to the photodiode. The pixel also includes a vertical overflow drain disposed in the semiconductor material and coupled to the pinning layer such that the pinning layer is disposed between the vertical overflow drain and the photodiode. A floating diffusion disposed in the semiconductor material proximate to the photodiode, and a vertical transfer transistor is disposed in part in the semiconductor material and coupled to the photodiode to transfer the image charge from the photodiode to the floating diffusion in response to a transfer signal applied to the gate terminal of the vertical transfer transistor.

Abstract: An image sensor includes a photodiode disposed in a first semiconductor material to absorb photons incident on the image sensor and generate image charge. A floating diffusion is disposed in the first semiconductor material and positioned to receive the image charge from the photodiode, and a transfer transistor is coupled between the photodiode and the floating diffusion to transfer the image charge out of the photodiode into floating diffusion in response to a transfer signal. A source follower transistor with a gate terminal is coupled to the floating diffusion to output an amplified signal of the image charge in the floating diffusion. The gate terminal includes a second semiconductor material in contact with the floating diffusion, and a gate oxide is partially disposed between the second semiconductor material and the first semiconductor material. The second semiconductor material extends beyond the lateral bounds of the floating diffusion.

Abstract: An image sensor includes one or more photodiodes disposed in a semiconductor material to receive image light and generate image charge, and a floating diffusion to receive the image charge from the one or more photodiodes. One or more transfer transistors is coupled to transfer image charge in the one or more photodiodes to the floating diffusion, and a source follower transistor is coupled to amplify the image charge in the floating diffusion. The source follower includes a gate electrode (coupled to the floating diffusion), source and drain electrodes, and an active region disposed in the semiconductor material between the source and drain electrodes. A dielectric material is disposed between the gate electrode and the active region and has a first thickness and a second thickness. The second thickness is greater than the first thickness, and the second thickness is disposed closer to the drain electrode than the first thickness.

Abstract: An image sensor pixel comprises a first charge storage node configured to have a first charge storage electric potential; a second charge storage node configured to have a second charge storage electric potential and receive charge from the first charge storage node, wherein the second charge storage electric potential is greater than the first charge storage electric potential; and a transfer circuit coupled between the first and the second charge storage nodes, wherein the transfer circuit comprises at least three transfer regions, wherein: a first transfer region is proximate to the first charge storage node and configured to have a first transfer electric potential greater than the first charge storage electric potential and lower than the second charge storage electric potential; a second transfer region is coupled between the first and a third transfer region and configured to have a second transfer electric potential greater than the first charge storage electric potential and lower than the second cha

Abstract: An image sensor pixel array comprises a center region and two parallel edge regions, wherein the center region is between the two parallel edge regions. The center region comprises a plurality of image pixels disposed along first sub-array of rows and columns, wherein each of the plurality of image pixels comprises a first micro-lens (ML) formed at an offset position above a first light receiving element as a countermeasure for shortening of exit pupil distance of the image pixel in the center region, and each of the two parallel edge regions comprises a plurality of phase detection auto-focus (PDAF) pixels disposed along second sub-array of rows and columns, wherein each of the plurality of PDAF pixels comprises a second micro-lens (ML) formed at an alignment position above a second light receiving element; and at least one of the PDAF pixels is located at a distance away from center of the edge region to receive incident light along an injection tilt angle.

Abstract: An image sensor includes a plurality of photodiodes disposed in a semiconductor material to convert image light into image charge. A floating diffusion is disposed proximate to the plurality of photodiodes to receive the image charge from the plurality of photodiodes. A plurality of transfer transistors is coupled to transfer the image charge from the plurality of photodiodes into the floating diffusion in response to a voltage applied to the gate terminal of the plurality of transfer transistors. A first trench isolation structure extends from a frontside of the semiconductor material into the semiconductor material and surrounds the plurality of photodiodes. A second trench isolation structure extends from a backside of the semiconductor material into the semiconductor material. The second trench isolation structure is disposed between individual photodiodes in the plurality of photodiodes.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by two micro-lenses, respectively. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array. A PDAF micro-lens is formed on the coating layer to cover the first image sensor pixels.

Abstract: An image sensor pixel array comprises a plurality of image pixel units to gather image information and a plurality of phase detection auto-focus (PDAF) pixel units to gather phase information. Each of the PDAF pixel units includes two of first image sensor pixels covered by a shared micro-lens. Each of the image pixel units includes four of second image sensor pixels adjacent to each other, wherein each of the second image sensor pixels is covered by an individual micro-lens. A coating layer is disposed on the micro-lenses and forms a flattened surface across the whole image sensor pixel array to receive incident light.

Abstract: An image sensor pixel includes a photodiode disposed in a semiconductor material to generate image charge in response to light incident on a backside of the semiconductor material, and a pinning layer disposed in the semiconducting material and coupled to the photodiode. The pixel also includes a vertical overflow drain disposed in the semiconductor material and coupled to the pinning layer such that the pinning layer is disposed between the vertical overflow drain and the photodiode. A floating diffusion disposed in the semiconductor material proximate to the photodiode, and a vertical transfer transistor is disposed in part in the semiconductor material and coupled to the photodiode to transfer the image charge from the photodiode to the floating diffusion in response to a transfer signal applied to the gate terminal of the vertical transfer transistor.

Abstract: A single-exposure high dynamic range (HDR) image sensor includes a first photodiode and a second photodiode, with a smaller full-well capacity than the first photodiode, disposed in a semiconductor material. The image sensor also includes a first floating diffusion disposed in the semiconductor material and a first transfer gate coupled to the first photodiode to transfer first image charge accumulated in the first photodiode into the first floating diffusion. A second floating diffusion is disposed in the semiconductor material and a second transfer gate is coupled to the second photodiode to transfer second image charge accumulated in the second photodiode into the second floating diffusion. An attenuation layer is disposed between the second photodiode and image light directed towards the single-exposure HDR image sensor to block a portion of the image light from reaching the second photodiode.

Abstract: An image sensor includes a photodiode disposed in a semiconductor material to generate image charge in response to incident light, and a floating diffusion disposed in the semiconductor material proximate to the photodiode. A transfer transistor is coupled to the photodiode to transfer the image charge from the photodiode into the floating diffusion in response to a transfer signal applied to a transfer gate of the transfer transistor. A source follower transistor is coupled to the floating diffusion to amplify a charge on the floating diffusion. The source follower transistor includes a gate electrode including a semiconductor material having a first dopant type; a source electrode, having a second dopant type, disposed in the semiconductor material; a drain electrode, having the second dopant type, disposed in the semiconductor material; and a channel, having the second dopant type, disposed between the source electrode and the drain electrode.

Abstract: An image sensor includes a photodiode disposed in a semiconductor material to generate image charge in response to incident light, and a floating diffusion disposed in the semiconductor material proximate to the photodiode. A transfer transistor is coupled to the photodiode to transfer the image charge from the photodiode into the floating diffusion in response to a transfer signal applied to a transfer gate of the transfer transistor. A source follower transistor is coupled to the floating diffusion to amplify a charge on the floating diffusion. The source follower transistor includes a gate electrode including a semiconductor material having a first dopant type; a source electrode, having a second dopant type, disposed in the semiconductor material; a drain electrode, having the second dopant type, disposed in the semiconductor material; and a channel, having the second dopant type, disposed between the source electrode and the drain electrode.

Abstract: A chip scale package (CSP) structure for an image sensor comprises an image sensor chip, wherein the image sensor chip comprises a semiconductor substrate having a top surface to receive light, a plurality of color filters disposed over the top surface, and a plurality of micro lenses disposed on the plurality of color filters. A low refractive index material is disposed over the image sensor chip, wherein the low refractive index material covers the plurality of micro lenses, and wherein a refractive index of the low refractive index material is lower than a refractive index of the plurality of micro lenses. A cover glass is disposed directly on the low refractive index material, wherein no air gap is between the cover glass and the low refractive index material, and between the low refractive index material and the image sensor chip. Therefore, the cover glass is fully supported by the low refractive index material without any dams.

Abstract: A chip scale package (CSP) structure for an image sensor comprises an image sensor chip, wherein the image sensor chip comprises a semiconductor substrate having a top surface to receive light, a plurality of color filters disposed over the top surface, and a plurality of micro lenses disposed on the plurality of color filters. A low refractive index material is disposed over the image sensor chip, wherein the low refractive index material covers the plurality of micro lenses, and wherein a refractive index of the low refractive index material is lower than a refractive index of the plurality of micro lenses. A cover glass is disposed directly on the low refractive index material, wherein no air gap is between the cover glass and the low refractive index material, and between the low refractive index material and the image sensor chip. Therefore, the cover glass is fully supported by the low refractive index material without any dams.