Abstract: Methods and semiconductor devices are provided. A method includes determining a location of a polyimide opening (PIO) corresponding to an under-bump metallization (UBM) feature in a die. The die includes a substrate and an interconnect structure over the substrate. The method also includes determining a location of a stacked via structure in the interconnect structure based on the location of the PIO. The method further includes forming, in the interconnect structure, the stacked via structure comprising at most three stacked contact vias at the location of the PIO.

Abstract: An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

Abstract: An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

Abstract: An image sensor device is provided. The image sensor device includes a semiconductor substrate having a front surface, a back surface opposite to the front surface, and a light-sensing region close to the front surface. The image sensor device includes an insulating layer covering the back surface and extending into the semiconductor substrate. The protection layer has a first refractive index, and the first refractive index is less than a second refractive index of the semiconductor substrate and greater than a third refractive index of the insulating layer, and the protection layer conformally and continuously covers the back surface and extends into the semiconductor substrate. The image sensor device includes a reflective structure surrounded by insulating layer in the semiconductor substrate.

Abstract: A method includes etching a semiconductor substrate to form a trench, filling a dielectric layer into the trench, with a void being formed in the trench and between opposite portions of the dielectric layer, etching the dielectric layer to reveal the void, forming a diffusion barrier layer on the dielectric layer, and forming a high-reflectivity metal layer on the diffusion barrier layer. The high-reflectivity metal layer has a portion extending into the trench. A remaining portion of the void is enclosed by the high-reflectivity metal layer.

Abstract: The present disclosure relates to an integrated chip that has a light sensing element arranged within a substrate. An absorption enhancement structure is arranged along a back-side of the substrate, and an interconnect structure is arranged along a front-side of the substrate. A reflection structure includes a dielectric structure and a plurality of semiconductor pillars that matingly engage the dielectric structure. The dielectric structure and semiconductor pillars are arranged along the front-side of the substrate and are spaced between the light sensing element and the interconnect structure. The plurality of semiconductor pillars and the dielectric structure are collectively configured to reflect incident light that has passed through the absorption enhancement structure and through the light sensing element back towards the light sensing element before the incident light strikes the interconnect structure.

Abstract: An image sensor device is provided. The image sensor device includes a semiconductor substrate having a first side, a second side opposite to the first side, and at least one light-sensing region close to the first side. The image sensor device includes a dielectric feature covering the second side and extending into the semiconductor substrate. The dielectric feature in the semiconductor substrate surrounds the light-sensing region. The image sensor device includes a reflective layer in the dielectric feature in the semiconductor substrate, wherein a top portion of the reflective layer protrudes away from the second side, and a top surface of the reflective layer and a top surface of the insulating layer are substantially coplanar.

Abstract: A method includes etching a semiconductor substrate to form a trench, filling a dielectric layer into the trench, with a void being formed in the trench and between opposite portions of the dielectric layer, etching the dielectric layer to reveal the void, forming a diffusion barrier layer on the dielectric layer, and forming a high-reflectivity metal layer on the diffusion barrier layer. The high-reflectivity metal layer has a portion extending into the trench. A remaining portion of the void is enclosed by the high-reflectivity metal layer.

Abstract: A semiconductor device includes a device layer, a semiconductor layer, a sensor element, a dielectric layer, a color filter layer, and a micro-lens. The semiconductor layer is over the device layer. The semiconductor layer has a plurality of microstructures thereon. Each of the microstructures has a substantially triangular cross-section. The sensor element is under the microstructures of the semiconductor layer and is configured to sense incident light. The dielectric layer is over the microstructures of the semiconductor layer. The color filter layer is over the dielectric layer. The micro-lens is over the color filter layer.

Abstract: A semiconductor device includes a device layer, a semiconductor layer, a sensor element, a dielectric layer, a color filter layer, and a micro-lens. The semiconductor layer is over the device layer. The semiconductor layer has a plurality of microstructures thereon. Each of the microstructures has a substantially triangular cross-section. The sensor element is under the microstructures of the semiconductor layer and is configured to sense incident light. The dielectric layer is over the microstructures of the semiconductor layer. The color filter layer is over the dielectric layer. The micro-lens is over the color filter layer.

Abstract: The present disclosure relates to an integrated chip that has a light sensing element arranged within a substrate. An absorption enhancement structure is arranged along a back-side of the substrate, and an interconnect structure is arranged along a front-side of the substrate. A reflection structure includes a dielectric structure and a plurality of semiconductor pillars that matingly engage the dielectric structure. The dielectric structure and semiconductor pillars are arranged along the front-side of the substrate and are spaced between the light sensing element and the interconnect structure. The plurality of semiconductor pillars and the dielectric structure are collectively configured to reflect incident light that has passed through the absorption enhancement structure and through the light sensing element back towards the light sensing element before the incident light strikes the interconnect structure.

Abstract: An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

Abstract: The present disclosure relates to an integrated chip that has a light sensing element arranged within a substrate. An absorption enhancement structure is arranged along a back-side of the substrate, and an interconnect structure is arranged along a front-side of the substrate. A reflection structure includes a dielectric structure and a plurality of semiconductor pillars that matingly engage the dielectric structure. The dielectric structure and semiconductor pillars are arranged along the front-side of the substrate and are spaced between the light sensing element and the interconnect structure. The plurality of semiconductor pillars and the dielectric structure are collectively configured to reflect incident light that has passed through the absorption enhancement structure and through the light sensing element back towards the light sensing element before the incident light strikes the interconnect structure.

Abstract: An image sensor with high quantum efficiency is provided. In some embodiments, a semiconductor substrate includes a non-porous semiconductor layer along a front side of the semiconductor substrate. A periodic structure is along a back side of the semiconductor substrate. A high absorption layer lines the periodic structure on the back side of the semiconductor substrate. The high absorption layer is a semiconductor material with an energy bandgap less than that of the non-porous semiconductor layer. A photodetector is in the semiconductor substrate and the high absorption layer. A method for manufacturing the image sensor is also provided.

Abstract: An image sensor with an absorption enhancement semiconductor layer is provided. In some embodiments, the image sensor comprises a front-side semiconductor layer, an absorption enhancement semiconductor layer, and a back-side semiconductor layer that are stacked. The absorption enhancement semiconductor layer is stacked between the front-side and back-side semiconductor layers. The absorption enhancement semiconductor layer has an energy bandgap less than that of the front-side semiconductor layer. Further, the image sensor comprises a plurality of protrusions and a photodetector. The protrusions are defined by the back-side semiconductor layer, and the photodetector is defined by the front-side semiconductor layer, the absorption enhancement semiconductor layer, and the back-side semiconductor layer.

Abstract: An image sensor with an absorption enhancement semiconductor layer is provided. In some embodiments, the image sensor comprises a front-side semiconductor layer, an absorption enhancement semiconductor layer, and a back-side semiconductor layer that are stacked. The absorption enhancement semiconductor layer is stacked between the front-side and back-side semiconductor layers. The absorption enhancement semiconductor layer has an energy bandgap less than that of the front-side semiconductor layer. Further, the image sensor comprises a plurality of protrusions and a photodetector. The protrusions are defined by the back-side semiconductor layer, and the photodetector is defined by the front-side semiconductor layer, the absorption enhancement semiconductor layer, and the back-side semiconductor layer.

Abstract: An image sensor device is provided. The image sensor device includes a semiconductor substrate having a first side, a second side opposite to the first side, and at least one light-sensing region close to the first side. The image sensor device includes a dielectric feature covering the second side and extending into the semiconductor substrate. The dielectric feature in the semiconductor substrate surrounds the light-sensing region. The image sensor device includes a reflective layer in the dielectric feature in the semiconductor substrate, wherein a top portion of the reflective layer protrudes away from the second side, and a top surface of the reflective layer and a top surface of the insulating layer are substantially coplanar.

Abstract: A method for forming an image sensor device is provided. The method includes providing a semiconductor substrate including a front surface, a back surface opposite to the front surface, at least one light-sensing region close to the front surface, and a first trench surrounding the light-sensing region. The method includes forming an insulating layer over the back surface and in the first trench. A void is formed in the insulating layer in the first trench, and the void is closed. The method includes removing the insulating layer over the void to open up the void. The opened void forms a second trench partially in the first trench. The method includes filling a reflective structure in the second trench. The reflective structure has a light reflectivity ranging from about 70% to about 100%.

Abstract: The present disclosure relates to an integrated chip that has a light sensing element arranged within a substrate. An absorption enhancement structure is arranged along a back-side of the substrate, and an interconnect structure is arranged along a front-side of the substrate. A reflection structure includes a dielectric structure and a plurality of semiconductor pillars that matingly engage the dielectric structure. The dielectric structure and semiconductor pillars are arranged along the front-side of the substrate and are spaced between the light sensing element and the interconnect structure. The plurality of semiconductor pillars and the dielectric structure are collectively configured to reflect incident light that has passed through the absorption enhancement structure and through the light sensing element back towards the light sensing element before the incident light strikes the interconnect structure.

Abstract: The present disclosure relates to an integrated chip that has a light sensing element arranged within a substrate. An absorption enhancement structure is arranged along a back-side of the substrate, and an interconnect structure is arranged along a front-side of the substrate. A reflection structure includes a dielectric structure and a plurality of semiconductor pillars that matingly engage the dielectric structure. The dielectric structure and semiconductor pillars are arranged along the front-side of the substrate and are spaced between the light sensing element and the interconnect structure. The plurality of semiconductor pillars and the dielectric structure are collectively configured to reflect incident light that has passed through the absorption enhancement structure and through the light sensing element back towards the light sensing element before the incident light strikes the interconnect structure.