# US 2014/0197301 A1 · Global shutter image sensors with light guide and light shield structures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0197301 A1 - Document ID: US20140197301A1 - Status: Published application - Kind: A1 - Application number: 14/157,492 - Filed: 2014-01-16 - Published: 2014-07-17 - Earliest claimed: 2013-01-17 - Assignees: Aptina Imaging Corporation - Applicants: Aptina Imaging Corporation - Inventors: Sergey Velichko; Gennadiy Agranov; Victor Lenchenkov - Web page: https://patentgrep.com/patent/US20140197301A1 ## CPC - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - H04N 23/689: {Motion occurring during a rolling shutter mode} - H04N 25/77: Pixel circuitry, e.g. memories, A/D converters, pixel amplifiers, shared circuits or shared components - H04N 25/771: comprising storage means other than floating diffusion - H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract An image sensor operable in global shutter mode may include an array of image pixels. Each image pixel may include a photodiode for detecting incoming light and a separate storage diode for temporarily storing charge. To maximize the efficiency of the image pixel array, image pixels may include light guide structures and light shield structures. The light guide structures may be used to funnel light away from the storage node and into the photodiode, while the light shield structures may be formed over storage nodes to block light from entering the storage nodes. The light guide structures may fill cone-shaped cavities in a dielectric layer, or the light guide structures may form sidewalls having a ring-shaped horizontal cross section. Metal interconnect structures in the dielectric layer may be arranged in concentric annular structures to form a near-field diffractive element that funnels light towards the appropriate photodiode. ## Claims ### Claim 1 An image sensor operable in global shutter mode and having a substrate and a dielectric material formed over the substrate, comprising: a photodiode formed in the substrate; a storage node formed in the substrate; a light guide structure formed in the dielectric material over the photodiode, wherein the light guide structure has a higher refractive index than that of the dielectric material; and a light shield formed in the dielectric material over the storage node, wherein a portion of the light guide overlaps a portion of the light shield. ### Claim 2 (depends on 1) The image sensor defined in claim 1 further comprising an anti-reflective coating that at least partially covers the light shield. ### Claim 3 (depends on 2) The image sensor defined in claim 2 further comprising a storage gate formed on the substrate, wherein the light shield at least partially covers the storage gate. ### Claim 4 (depends on 3) The image sensor defined in claim 3 wherein the light shield comprises a metal selected from the group consisting of: tungsten, aluminum, and copper. ### Claim 5 (depends on 1) The image sensor defined in claim 1 wherein the dielectric material comprises a cone-shaped cavity and wherein the light guide structure fills the cone-shaped cavity. ### Claim 6 (depends on 5) The image sensor defined in claim 5 wherein the light guide structure comprises organo-siloxane-based polymer material and wherein the dielectric material comprises silicon oxide. ### Claim 7 (depends on 6) The image sensor defined in claim 6 wherein the dielectric material has sidewall surfaces that define the cone-shaped cavity and wherein the image sensor further comprises a thin film reflective coating formed on the sidewall surfaces. ### Claim 8 An image sensor operable in global shutter mode and having a substrate and a dielectric material formed over the substrate, comprising: a photodiode formed in the substrate; a storage node formed in the substrate; a light guide structure formed in the dielectric material over the photodiode, wherein the light guide structure has a ring-shaped horizontal cross section with an inner perimeter defined by an inner surface of the light guide structure and an outer perimeter defined by an outer surface of the light guide structure, and wherein the light guide structure has a higher refractive index than that of the dielectric material; and a light shield formed in the dielectric material over the storage node. ### Claim 9 (depends on 8) The image sensor defined in claim 8 wherein the light guide structure forms light guide sidewalls, wherein a portion of the dielectric material is completely surrounded by the light guide sidewalls, and wherein the portion of the dielectric material overlaps the photodiode. ### Claim 10 (depends on 9) The image sensor defined in claim 9 further comprising an anti-reflective coating that at least partially covers the light shield. ### Claim 11 (depends on 10) The image sensor defined in claim 10 further comprising a storage gate formed on the substrate, wherein the light shield at least partially covers the storage gate. ### Claim 12 (depends on 9) The image sensor defined in claim 9 wherein a portion of the light guide structure overlaps a portion of the light shield. ### Claim 13 An image sensor operable in global shutter mode and having a substrate and a dielectric material formed over the substrate, comprising: a photodiode formed in the substrate; a storage node formed in the substrate; and a plurality of concentric annular metal structures formed in the dielectric material over the storage node, wherein the plurality of metal rings form a near-field diffractive element that guides light towards the photodiode, wherein a portion of the dielectric material is surrounded by the plurality of concentric annular metal structures, and wherein the portion of the dielectric material overlaps the photodiode. ### Claim 14 (depends on 13) The image sensor defined in claim 13 wherein the plurality of concentric annular metal structures comprises a first metal ring located a first distance from the substrate, a second metal ring located a second distance from the substrate, and a third metal ring located a third distance from the substrate, wherein the second distance is less than the first distance and greater than the third distance. ### Claim 15 (depends on 14) The image sensor defined in claim 14 wherein the first metal ring has a first diameter, the second metal ring has a second diameter, and the third metal ring has a third diameter, wherein the second diameter is less than the first diameter and greater than the third diameter. ### Claim 16 (depends on 15) The image sensor defined in claim 15 further comprising a fourth metal ring located the second distance from the substrate and having a fourth diameter larger than the second diameter. ### Claim 17 (depends on 16) The image sensor defined in claim 16 further comprising fifth and sixth metal rings located the third distance from the substrate and having respective fifth and sixth diameters that are larger than the third diameter. ### Claim 18 (depends on 13) The image sensor defined in claim 13 further comprising: a light shield formed in the dielectric material over the storage node; and an anti-reflective coating that at least partially covers the light shield. ### Claim 19 (depends on 18) The image sensor defined in claim 18 wherein the light shield comprises a metal selected from the group consisting of: tungsten, aluminum, and copper. ### Claim 20 (depends on 19) The image sensor defined in claim 19 further comprising a storage gate formed on the substrate, wherein the light shield at least partially covers the storage gate, and wherein the light shield has an opening through which one of the concentric annular metal structures electrically couples to the storage gate.