# US 8,569,807 B2 · Backside illuminated image sensor having capacitor on pixel region > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,569,807 B2 - Document ID: US8569807B2 - Status: Granted - Kind: B2 - Application number: 12/820,656 - Filed: 2010-06-22 - Published: 2011-03-03 - Granted: 2013-10-29 - Earliest claimed: 2009-09-01 - Assignees: Taiwan Semiconductor Manufacturing Company, Ltd. - Applicants: Chun-Chieh Chuang; Dun-Nian Yuang; Jen-Cheng Liu; Jeng-Shyan Lin; Wen-De Wang - Inventors: Chun-Chieh Chuang; Dun-Nian Yuang; Jen-Cheng Liu; Jeng-Shyan Lin; Wen-De Wang - Web page: https://patentgrep.com/patent/US8569807B2 ## CPC - H10F 39/8033: {Photosensitive area} - H10F 39/18: Complementary metal-oxide-semiconductor [CMOS] image sensors; Photodiode array image sensors - H10F 39/199: {Back-illuminated image sensors} - H10F 39/803: {Pixels having integrated switching, control, storage or amplification elements} - H10D 1/68: Capacitors having no potential barriers - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES ## Abstract A backside illuminated image sensor includes a semiconductor substrate having a front side and backside, a sensor element formed overlying the frontside of the semiconductor substrate, and a capacitor formed overlying the sensor element. ## Claims ### Claim 1 A backside illuminated image sensor, comprising: a semiconductor substrate having a frontside and a backside; a sensor element formed overlying the frontside of the semiconductor substrate, the sensor element comprising: a transistor structure including a gate, a spacer, a source and a drain, and a light sensing region disposed in the source, the light sensing region having a dopant type opposite a dopant type of the source, wherein the light sensing region extends beneath the spacer of the transistor structure; and a capacitor formed overlying the sensor element, wherein the capacitor overlies an entirety of the light sensing region in one direction and the capacitor is electrically connected to the drain; a plurality of dielectric layers overlying the sensor element; and an interconnection structure formed in the plurality of dielectric layers; wherein at least two metal layers of the interconnection structure and at least one of the plurality of dielectric layers between the at least two metal layers form the capacitor and an additional metal layer of the interconnect is electrically connected between the sensor element and the capacitor. ### Claim 2 (depends on 1) The backside illuminated image sensor of claim 1, wherein the capacitor comprises a metal-insulator-metal (MIM) capacitor. ### Claim 3 (depends on 1) The backside illuminated image sensor of claim 1, wherein the capacitor comprises a metal-oxide-metal (MOM) capacitor. ### Claim 4 (depends on 1) The backside illuminated image sensor of claim 1, wherein the semiconductor substrate comprises a pixel region, and the sensor element is formed in the pixel region. ### Claim 5 (depends on 4) The backside illuminated image sensor of claim 4, wherein the capacitor is formed in the pixel region. ### Claim 6 (depends on 4) The backside illuminated image sensor of claim 4, wherein the sensor element comprises a light-sensing region in the pixel region on the frontside of the semiconductor substrate. ### Claim 7 (depends on 4) The backside illuminated image sensor of claim 4, wherein the sensor element comprises a transistor structure on the frontside of the semiconductor substrate. ### Claim 8 (depends on 1) The backside illuminated image sensor of claim 1, wherein the capacitor is electrically coupled to the sensor element. ### Claim 9 (depends on 1) The backside illuminated image sensor of claim 1, wherein at least one metal layer of the interconnect structure comprises copper. ### Claim 10 A backside illuminated image sensor, comprising: a semiconductor substrate having a frontside and a backside, wherein a pixel region is defined on the frontside; a transistor structure in the pixel region overlying the frontside of the semiconductor substrate, wherein the transistor structure comprises a gate electrode formed on the frontside of the semiconductor substrate, a spacer, and source/drain regions formed in the frontside of the semiconductor substrate laterally adjacent the gate electrode; a light-sensing element formed on the source region, the light-sensing element having a dopant type opposite a dopant type of the source region in which the light-sensing element is formed, wherein the light-sensing element extends beneath the spacer of the transistor structure; a capacitor formed overlying an entirety of the light-sensing element in one direction and electrically coupled to the transistor structure in the drain region; a plurality of dielectric layers overlying the transistor structure and the light-sensing element; and an interconnection structure formed in the plurality of dielectric layers; wherein at least two metal layers of the interconnection structure and at least one of the plurality of dielectric layers formed between the at least two metal layers form the capacitor and an additional metal layer of the interconnect is electrically connected between the sensor element and the capacitor. ### Claim 11 (depends on 10) The backside illuminated image sensor of claim 10, wherein the capacitor comprises a metal-insulator-metal (MIM) capacitor. ### Claim 12 (depends on 10) The backside illuminated image sensor of claim 10, wherein the capacitor comprises a metal-oxide-metal (MOM) capacitor. ### Claim 13 (depends on 10) The backside illuminated image sensor of claim 10, wherein the capacitor is formed in the pixel region. ### Claim 14 (depends on 10) The backside illuminated image sensor of claim 10, wherein the capacitor comprises a bottom electrode, a top electrode and a capacitor dielectric layer formed between the bottom electrode and the top electrode, and at least one of the bottom electrode and the top electrode comprises copper. ### Claim 15 (depends on 10) The backside illuminated image sensor of claim 10, wherein the light-sensing region is a photodiode region. ### Claim 16 (depends on 1) The backside illuminated image sensor of claim 1, further comprising at least one color filter attached to the backside of the substrate. ### Claim 17 (depends on 1) The backside illuminated image sensor of claim 1, further comprising at least one lens disposed on the backside of the substrate. ### Claim 18 (depends on 1) The backside illuminated image sensor of claim 1, further comprising a plurality of sensor elements, each sensor element configured to correspond to a red light wavelength, a blue light wavelength or a green light wavelength. ### Claim 19 (depends on 10) The backside illuminated image sensor of claim 10, further comprising at least one color filter attached to the backside of the substrate. ### Claim 20 (depends on 10) The backside illuminated image sensor of claim 10, further comprising at least one lens disposed on the backside of the substrate.