# US 2013/0154041 A1 · Solid-state image sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0154041 A1 - Document ID: US20130154041A1 - Status: Published application - Kind: A1 - Application number: 13/601,439 - Filed: 2012-08-31 - Published: 2013-06-20 - Earliest claimed: 2011-12-20 - Assignees: Kabushiki Kaisha Toshiba - Inventors: Koichi Kokubun; Yusaku Konno - Web page: https://patentgrep.com/patent/US20130154041A1 ## CPC - H10F 39/12: Image sensors - H10F 39/024: {of coatings or optical elements} - H10F 39/8053: {Colour filters} - H10F 77/40: Optical elements or arrangements (surface textures H10F77/70) - H10F 77/337: {using interference filters, e.g. multilayer dielectric filters} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract According to one embodiment, there is provided a solid-state image sensor including a photoelectric conversion layer, and a multilayer interference filter. The multilayer interference filter is arranged to conduct light of a particular color, of incident light, selectively to the photoelectric conversion layer. The multilayer interference filter has a laminate structure in which a first layer having a first refraction index and a second layer having a second refraction index are repeatedly laminated, and a third layer which is in contact with a lower surface of the laminate structure and has a third refraction index. A lowermost layer of the laminate structure is the second layer. The third refraction index is not equal to the first refraction index and is higher than the second refraction index. ## Claims ### Claim 1 A solid-state image sensor comprising: a photoelectric conversion layer; and a multilayer interference filter which is arranged to conduct light of a particular color, of incident light, selectively to the photoelectric conversion layer, wherein the multilayer interference filter has a laminate structure in which a first layer having a first refraction index and a second layer having a second refraction index are repeatedly laminated, and a third layer which is in contact with a lower surface of the laminate structure and has a third refraction index, a lowermost layer of the laminate structure is the second layer, and the third refraction index is not equal to the first refraction index and is higher than the second refraction index. ### Claim 2 (depends on 1) The solid-state image sensor according to claim 1, wherein the third layer has an optical film thickness equal to or lower than 225 nm. ### Claim 3 (depends on 2) The solid-state image sensor according to claim 2, wherein: the third layer is formed of a material including silicon nitride; and the third layer has a film thickness equal to or lower than 112 nm. ### Claim 4 (depends on 2) The solid-state image sensor according to claim 2, wherein the third layer has an optical film thickness equal to or lower than 200 nm. ### Claim 5 (depends on 4) The solid-state image sensor according to claim 4, wherein: the third layer is formed of a material including silicon nitride as a main component; and the third layer has a film thickness equal to or lower than 100 nm. ### Claim 6 (depends on 3) The solid-state image sensor according to claim 3, wherein the third layer has an optical film thickness equal to or lower than 175 nm. ### Claim 7 (depends on 4) The solid-state image sensor according to claim 4, wherein: the third layer is formed of a material including silicon nitride as a main component; and the third layer has a film thickness equal to or lower than 88 nm. ### Claim 8 (depends on 4) The solid-state image sensor according to claim 4, wherein: the third layer has an optical film thickness equal to or lower than 150 nm. ### Claim 9 (depends on 4) The solid-state image sensor according to claim 4, wherein: the third layer is formed of a material including silicon nitride as a main component; and the third layer has a film thickness equal to or lower than 75 nm. ### Claim 10 (depends on 1) The solid-state image sensor according to claim 1, wherein the third layer has an optical film thickness equal to or greater than 125 nm. ### Claim 11 (depends on 10) The solid-state image sensor according to claim 10, wherein: the third layer is formed of a material including silicon nitride as a main component; and the third layer has a film thickness equal to or greater than 62 nm. ### Claim 12 (depends on 1) The solid-state image sensor according to claim 1, wherein: the second refraction index is lower than the first refraction index; and the third refraction index is lower than the first refraction index and higher than the second refraction index. ### Claim 13 (depends on 1) The solid-state image sensor according to claim 1, further comprising: a second photoelectric conversion layer; and a second multilayer interference filter which is arranged to conduct light of a second color different from the particular color, of incident light, selectively to the second photoelectric conversion layer, and wherein the second multilayer interference filter has a second laminate structure in which the first layer and the second layer are repeatedly laminated, and a fourth layer which is in contact with a lower surface of the second laminate structure and has a fourth refraction index, a lowermost layer of the second laminate structure is the second layer, and the fourth refraction index is not equal to the first refraction index, and is equal to the second refraction index. ### Claim 14 (depends on 13) The solid-state image sensor according to claim 13, wherein the fourth layer has a film thickness equal to the film thickness of the third layer. ### Claim 15 (depends on 13) The solid-state image sensor according to claim 13, wherein the film thickness of the fourth layer is thinner than the film thickness of the third layer. ### Claim 16 (depends on 13) The solid-state image sensor according to claim 13, wherein the second multilayer interference filter further has a sixth layer, which is in contact with a lower surface of the fourth layer and has the third refraction index. ### Claim 17 (depends on 16) The solid-state image sensor according to claim 16, wherein total of the film thickness of the fourth layer and the film thickness of the sixth layer is equal to the film thickness of the third layer. ### Claim 18 (depends on 1) The solid-state image sensor according to claim 1, further comprising: a third photoelectric conversion layer; and a third multilayer interference filter which is arranged to conduct light of a third color different from the particular color, of incident light, selectively to the third photoelectric conversion layer, and wherein the third multilayer interference filter has a third laminate structure in which the first layer and the second layer are repeatedly laminated, and a fifth layer which is in contact with an upper surface of the third laminate structure and has a fifth refraction index, and wherein an uppermost layer of the third laminate structure is the second layer, and the fifth refraction index is not equal to the first refraction index and is higher than the second refraction index. ### Claim 19 (depends on 1) The solid-state image sensor according to claim 1, further comprising: a second photoelectric conversion layer; and a second multilayer interference filter which is arranged to conduct light of a second color different from the particular color, of incident light, selectively to the second photoelectric conversion layer, and wherein the second multilayer interference filter has a second laminate structure in which the first layer and the second layer repeatedly laminated, a sixth layer which is in contact with a lower surface of the second laminate structure and has the third refraction index, and a fourth layer which is in contact with a lower surface of the sixth layer and has a fourth refraction index, wherein a lowermost layer of the second laminate structure is the second layer, and the fourth refraction index is not equal to the first refraction index, and is equal to the second refraction index. ### Claim 20 (depends on 19) The solid-state image sensor according to claim 19, wherein total of the film thickness of the sixth layer and the film thickness of the fourth layer is equal to the film thickness of the third layer.