# US 2014/0151835 A1 · Backside illuminated image sensors and method of making the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151835 A1 - Document ID: US20140151835A1 - Status: Published application - Kind: A1 - Application number: 14/172,053 - Filed: 2014-02-04 - Published: 2014-06-05 - Earliest claimed: 2009-04-23 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Taiwan Semiconductor Manufacturing Company, Ltd. - Inventors: Kuan-Chieh HUANG; Chih-Jen WU; Chen-Ming HUANG; Dun-Nian YAUNG; An-Chun TU - Web page: https://patentgrep.com/patent/US20140151835A1 ## CPC - H10W 10/17: formed using trench refilling with dielectric materials, e.g. shallow trench isolations - H10F 39/014: {of CMOS image sensors} - H10F 39/024: {of coatings or optical elements} - H10F 39/026: {Wafer-level processing} - H10F 39/199: {Back-illuminated image sensors} - H10F 39/8053: {Colour filters} - H10F 39/806: {Optical elements or arrangements associated with the image sensors} - H10F 39/8063: {Microlenses} - H10F 39/807: {Pixel isolation structures} - H10F 71/129: {Passivating} - H10W 10/014: {using trench refilling with dielectric materials, e.g. shallow trench isolations} - H10W 10/0148: {comprising introducing impurities in side walls or bottom walls of trenches, e.g. for forming channel stoppers} - H10F 39/811: {Interconnections} - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract A backside illuminated image sensor includes a substrate with a substrate depth, where the substrate includes a pixel region and a peripheral region. The substrate further includes a front surface and a back surface. The backside illuminated image sensor includes a first isolation structure formed in the pixel region of the substrate, where a bottom of the first isolation structure is exposed at the back surface of the substrate. The backside illuminated image sensor includes a second isolation structure formed in the peripheral region of the substrate, where the second isolation structure has a depth less than a depth of the first isolation structure. The backside illuminated image sensor includes an implant region adjacent to at least a portion of sidewalls of each isolation structure in the pixel region. ## Claims ### Claim 1 A backside illuminated image sensor, comprising: a substrate comprising a pixel region and a peripheral region, wherein the substrate includes a front surface and a back surface; a first isolation structure formed in the pixel region of the substrate, wherein a bottom of the first isolation structure is exposed at the back surface of the substrate; a second isolation structure formed in the peripheral region of the substrate, wherein the second isolation structure has a depth less than a depth of the first isolation structure; and an implant region adjacent to at least a portion of sidewalls of each isolation structure in the pixel region, wherein the portion of the sidewalls are located closer to the back surface than a top surface of the substrate, wherein the second isolation structure is free of the implant region. ### Claim 2 (depends on 1) The backside illuminated image sensor of claim 1, wherein the substrate comprises a p-type dopant. ### Claim 3 (depends on 1) The backside illuminated image sensor of claim 1 further comprising, an inter-layer dielectric layer disposed over the front surface of the substrate. ### Claim 4 (depends on 1) The backside illuminated image sensor of claim 1, wherein a distance from a first point on the first isolation structure closest to the front surface to a second point on the first isolation structure closest to the back surface ranges from 1 micrometer (μm) to 10 μm. ### Claim 5 (depends on 1) The backside illuminated image sensor of claim 1, wherein a distance from a first point on the second isolation structure closest to the front surface to a second point on the second isolation structure closest to the back surface is less than about 1 μm. ### Claim 6 (depends on 1) The backside illuminated image sensor of claim 1 further comprising, a sensor element formed in the front surface of the substrate. ### Claim 7 (depends on 6) The backside illuminated image sensor of claim 6, wherein the sensor element comprises at least one of a photodiode, a pinned layer photodiode, a non-pinned layer photodiode, a reset transistor, a source follower transistor, a transfer transistor, a select transistor, a complimentary metal-oxide-semiconductor image sensor, a charged coupling device sensor, an active pixel sensor, or a passive pixel sensor. ### Claim 8 (depends on 6) The backside illuminated image sensor of claim 6, wherein a passivation layer is over the sensor element. ### Claim 9 (depends on 8) The backside illuminated image sensor of claim 8, wherein the interconnection structure comprises at least one of copper alloy, titanium, titanium nitride, tantalum, tantalum nitride, tungsten, polysilicon, nickel silicide, cobalt silicide, tungsten silicide, tantalum silicide, titanium silicide, platinum silicide, erbium silicide, or palladium silicide. ### Claim 10 A backside illuminated image sensor, comprising: a substrate having a first surface and a light receiving surface; a first isolation structure passing through the substrate, wherein the first isolation structure has a first depth and a bottom of the first isolation structure is exposed at the light receiving surface of the substrate; a sensor element in the first surface of the substrate; a color filter overlying the light receiving surface of the substrate; a second isolation structure in the substrate, wherein the second isolation structure has a second depth less than the first depth; and an implant region adjacent to at least a portion of sidewalls of each first isolation structure, wherein the portion of the sidewalls are located closer to the light receiving surface than the first surface of the substrate, wherein the second isolation structure is free of the implant region. ### Claim 11 (depends on 10) The backside illuminated image sensor of claim 10, wherein the substrate comprises an n-type dopant. ### Claim 12 (depends on 10) The backside illuminated image sensor of claim 10 further comprising, an inter-layer dielectric layer disposed over the first surface of the substrate. ### Claim 13 (depends on 12) The backside illuminated image sensor of claim 12, wherein the inter-layer dielectric layer comprises at least one of an undoped silica glass, a silicon nitride, a silicon oxynitride, a polyimide, a spin-on glass, a fluoride-doped silicate glass, or a carbon doped silicon oxide. ### Claim 14 (depends on 10) The backside illuminated image sensor of claim 10, wherein a distance from a first point on the first isolation structure closest to the first surface to a second point on the first isolation structure closest to the light receiving surface ranges from 1 micrometer (μm) to 10 μm. ### Claim 15 (depends on 10) The backside illuminated image sensor of claim 10, wherein a distance from a first point on the second isolation structure closest to the first surface to a second point on the second isolation structure closest to the light receiving surface is less than about 1 μm. ### Claim 16 (depends on 10) The backside illuminated image sensor of claim 10, wherein a passivation layer is over the sensor element. ### Claim 17 A method of making a backside illuminated image sensor, comprising: forming a first isolation structure in a pixel region of a substrate, the substrate comprising the pixel region and a peripheral region, wherein the substrate includes a front surface and a back surface; forming a second isolation structure in the peripheral region of the substrate, wherein the second isolation structure has a depth less than a depth of the first isolation structure; exposing a bottom of the first isolation structure at the back surface of the substrate; and forming an implant region adjacent to at least a portion of sidewalls of at least one isolation structure in the pixel region, wherein the second isolation structure is free of the implant region. ### Claim 18 (depends on 17) The method of claim 17 further comprising, forming a sensor element in the front surface of the substrate. ### Claim 19 (depends on 18) The method of claim 18 further comprising, disposing an inter-layer dielectric layer on the substrate. ### Claim 20 (depends on 19) The method of claim 19 further comprising, forming a passivation layer over the inter-layer dielectric layer.