# US 5,703,355 A · Image sensor covered by a protective film and an organic film to decrease variations in spectral sensitivity > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,355 A - Document ID: US5703355A - Status: Granted - Kind: A - Application number: 08/593,107 - Filed: 1996-02-01 - Granted: 1997-12-30 - Earliest claimed: 1993-04-20 - Assignees: Sony Corporation - Inventors: Seiichi Kawamoto - Web page: https://patentgrep.com/patent/US5703355A ## CPC - H10F 77/331: {for filtering or shielding light, e.g. multicolour filters for photodetectors} - H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION ## Abstract In a monochrome sensor, a sensor unit is covered with a protective film, and a light-transmitting organic film is formed on this protective film. Consequently, ripples in the spectral sensitivity characteristics are reduced. Even if the positions of the peaks and valleys of these ripples vary due to variations in the thicknesses of the protective film and the organic film or due to effective variations in these film thicknesses caused by the difference in the incident angle of light, a variation in the sensitivity at a given wavelength is small. This results in a small variation in the wavelength at which the maximum value of the spectral sensitivity is obtained and a small variation in the sensitivity derived from the difference in the incident angle of light. ## Claims ### Claim 1 A monochrome sensor, wherein a light-transmitting film is formed directly on top of a protective film without any layers of intervening material disposed therebetween, the protective film covering at least a sensor unit without any layers of intervening material disposed therebetween, said light-transmitting film forming an external light-incident surface for said sensor without any layers of material disposed on top of the light-transmitting film, whereby variations in the wavelength of the maximum spectral sensitivity of said sensor are reduced by said light-transmitting film. ### Claim 2 (depends on 1) A sensor according to claim 1, wherein said light-transmitting film is an organic film. ### Claim 3 (depends on 1) A sensor according to claim 1, wherein said image sensor is formed by using a solid-state image sensor. ### Claim 4 (depends on 2) A sensor according to claim 2, wherein said image sensor is formed by using a solid-state image sensor. ### Claim 5 (depends on 2) A sensor according to claim 2, wherein a thickness of said light-transmitting film is not less than 1.0 .mu.m. ### Claim 6 (depends on 1) A sensor according to claim 1, wherein said protective film is one of a plasma-SiN film and an SiO.sub.2 film. ### Claim 7 (depends on 1) A sensor according to claim 1, wherein a thickness of said protective film is not more than 0.75 .mu.m. ### Claim 8 (depends on 1) A sensor according to claim 1 wherein the light-transmitting film comprises an organic film comprising a resin selected from the group consisting of polyglycidylmethacrylate, an acrylic acid/n-butyl acrylate/methacrylate copolymer, a styrene/chloromethylstyrene copolymer, polyvinyl cinnamate and novalak. ### Claim 9 (depends on 8) A sensor according to claim 8 wherein the light-transmitting film is formed on top of the protective film by spin coating a solution of the resin dissolved in a solvent selected from the group consisting of ethylcellosolveacetate, diethyleneglycoldimethylether and ethyl lactate followed by removing the solvent with heat. ### Claim 10 A monochrome sensor comprising: a sensor unit, a protective film disposed directly on top of the upper surface of the sensor unit, an organic light-transmitting film disposed directly on top of the protective film, the organic light-transmitting film being directly exposed to light and providing a light-incident surface without any intervening layers disposed on top of the organic light-transmitting film, the organic light-transmitting film comprising a resin, the organic light-transmitting film reducing variations in the wavelength of the maximum spectral sensitivity of the sensor. ### Claim 11 (depends on 10) A sensor according to claim 10 the resin is selected from the group consisting of polyglycidylmethacrylate, an acrylic acid/n-butyl acrylate/methacrylate copolymer, a styrene/chloromethylstyrene copolymer, polyvinyl cinnamate and novalak. ### Claim 12 (depends on 11) A sensor according to claim 11 wherein the light-transmitting film is formed on top of the protective film by spin coating a solution of the resin dissolved in a solvent selected from the group consisting of ethylcellosolveacetate, diethyleneglycoldimethylether and ethyl lactate followed by removing the solvent with heat. ### Claim 13 (depends on 10) A sensor according to claim 10, wherein said monochrome sensor is formed by using a solid-state image sensor. ### Claim 14 (depends on 10) A sensor according to claim 10, wherein a thickness of said light-transmitting film is not less than 1.0 .mu.m. ### Claim 15 (depends on 10) A sensor according to claim 10, wherein said protective film is selected from the group consisting of a plasma SiN film and a SiO.sub.2 film. ### Claim 16 (depends on 10) A sensor according to claim 10, wherein a thickness of said protective film is not more than 0.75 .mu.m.