US20150380594A1 - Shielding film for a light receiving element and optically coupled insulating device - Google Patents

Shielding film for a light receiving element and optically coupled insulating device Download PDF

Info

Publication number
US20150380594A1
US20150380594A1 US14/852,084 US201514852084A US2015380594A1 US 20150380594 A1 US20150380594 A1 US 20150380594A1 US 201514852084 A US201514852084 A US 201514852084A US 2015380594 A1 US2015380594 A1 US 2015380594A1
Authority
US
United States
Prior art keywords
light receiving
film
layer
receiving element
insulating layer
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/852,084
Inventor
Miki Hidaka
Osamu Takata
Masahito NISHIGOORI
Yukiko Takiba
Hiroshi Suzunaga
Hiroshi Shimomura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Toshiba Corp
Original Assignee
Toshiba Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Toshiba Corp filed Critical Toshiba Corp
Priority to US14/852,084 priority Critical patent/US20150380594A1/en
Publication of US20150380594A1 publication Critical patent/US20150380594A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/12—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto
    • H01L31/16—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto the semiconductor device sensitive to radiation being controlled by the light source or sources
    • H01L31/167—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto the semiconductor device sensitive to radiation being controlled by the light source or sources the light sources and the devices sensitive to radiation all being semiconductor devices characterised by potential barriers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/552—Protection against radiation, e.g. light or electromagnetic waves
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L25/00—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof
    • H01L25/16—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits
    • H01L25/167—Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereof the devices being of types provided for in two or more different main groups of groups H01L27/00 - H01L33/00, or in a single subclass of H10K, H10N, e.g. forming hybrid circuits comprising optoelectronic devices, e.g. LED, photodiodes
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/1446—Devices controlled by radiation in a repetitive configuration
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/02002—Arrangements for conducting electric current to or from the device in operations
    • H01L31/02005—Arrangements for conducting electric current to or from the device in operations for device characterised by at least one potential jump barrier or surface barrier
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/02016—Circuit arrangements of general character for the devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0216—Coatings
    • H01L31/02161—Coatings for devices characterised by at least one potential jump barrier or surface barrier
    • H01L31/02162—Coatings for devices characterised by at least one potential jump barrier or surface barrier for filtering or shielding light, e.g. multicolour filters for photodetectors
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
    • H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
    • H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
    • H01L31/103—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the PN homojunction type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/12—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto
    • H01L31/14—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto the light source or sources being controlled by the semiconductor device sensitive to radiation, e.g. image converters, image amplifiers or image storage devices
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/12—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto
    • H01L31/16—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto the semiconductor device sensitive to radiation being controlled by the light source or sources
    • H01L31/165—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof structurally associated with, e.g. formed in or on a common substrate with, one or more electric light sources, e.g. electroluminescent light sources, and electrically or optically coupled thereto the semiconductor device sensitive to radiation being controlled by the light source or sources the semiconductor sensitive to radiation being characterised by at least one potential-jump or surface barrier

Definitions

  • Embodiments described herein relate generally a light receiving element and an optically coupled insulating device.
  • a noise component may occur in the light receiving element due to the electrostatic capacitance of an insulating layer between the input terminal and the output terminal.
  • Such noise can be reduced by covering the light receiving element with an electromagnetic shield film made of ITO (Indium Tin Oxide), a metal thin film having a mesh configuration, etc.
  • ITO Indium Tin Oxide
  • a metal thin film having a mesh configuration etc.
  • FIG. 1 is a schematic plan view of a light receiving element according to a first embodiment
  • FIG. 2 is a schematic cross-sectional view of the light receiving element along line A-A of the light receiving element of the first embodiment
  • FIG. 3A is a graph showing the dependence of the transmittance on the thickness of the electromagnetic shield film
  • FIG. 3B is a graph showing the sheet resistance for the reciprocal of the thickness of the electromagnetic shield film
  • FIG. 4 is a schematic cross-sectional view of an optically coupled insulating device including the light receiving element of the first embodiment
  • FIG. 5A is a schematic view showing a measurement system of the instantaneous common mode rejection voltage of the optically coupled insulating device; and FIG. 5B is a waveform diagram showing the change of the pulse voltage;
  • FIG. 6 is a schematic cross-sectional view of a light receiving element according to a second embodiment
  • FIG. 7 is a schematic cross-sectional view of a modification of the light receiving element of the second embodiment
  • FIGS. 8A to 8F are schematic views showing manufacturing processes of the electromagnetic shield film 24 including the metal nitride thin film.
  • FIGS. 9A to 9F are schematic views showing a modification of the manufacturing processes of the electromagnetic shield film including the metal nitride thin film.
  • a light receiving element includes: a semiconductor layer; an insulating layer; an interconnect layer; and a film.
  • the semiconductor layer includes a light receiving unit configured to convert a signal light incident on the light receiving unit into an electrical signal.
  • the insulating layer is provided on the semiconductor layer.
  • the interconnect layer is provided on the insulating layer.
  • the film is provided on the insulating layer to cover the light receiving unit and be connected to the interconnect layer, the film being made of a metal or a metal nitride.
  • FIG. 1 is a schematic plan view of a light receiving element according to a first embodiment.
  • the light receiving element 10 includes a semiconductor substrate, a semiconductor layer provided on the semiconductor substrate, a metal interconnect layer, an insulating layer, and an electromagnetic shield film including a metal nitride thin film or a metal thin film.
  • the semiconductor layer includes a light receiving unit 20 that converts a signal light incident on the light receiving unit 20 into an electrical signal.
  • the length of one side of one unit of the photodiodes included in the light receiving unit 20 may be 20 to 200 ⁇ m, etc.; and the units may be disposed in an array configuration or a mosaic array configuration.
  • the semiconductor layer may further include a signal processing circuit unit that processes and outputs the electrical signal.
  • the signal processing circuit unit includes a TIA (a Transimpedance Amp) 32 , a comparator 34 , an output circuit 36 , a current source 38 , an amplifier bias circuit 40 , etc.
  • the light receiving element 10 may include electrode pad units 42 to 46 , etc.
  • FIG. 2 is a schematic cross-sectional view of the light receiving element along line A-A of the light receiving element of the first embodiment.
  • a semiconductor substrate 70 may be, for example, Si, SiC, etc.
  • a semiconductor layer 72 that includes Si, etc., is provided on the semiconductor substrate 70 to include the light receiving unit 20 that converts a signal light Lin incident on the light receiving unit 20 into the electrical signal, and the signal processing circuit unit that processes and outputs the electrical signal.
  • the semiconductor substrate 70 is the p + -type; and an n-type layer is provided on the semiconductor substrate 70 .
  • a p + -type layer 72 a is formed by ion implantation, etc., from the front surface side to reach the semiconductor substrate 70 to separate the light receiving unit 20 from the signal processing circuit unit.
  • the light receiving unit 20 includes a high-resistance n-type layer 72 b, a p + -type layer 72 c, an n + -type layer 72 d, etc.
  • the conductivity types of the regions of the semiconductor substrate 70 and the semiconductor layer 72 may be the opposite of those of the structure of FIG. 2 .
  • Metal interconnect layers 50 are provided at the upper portion of the semiconductor layer 72 to be connected respectively to the light receiving unit 20 and a signal processing circuit unit 30 .
  • the multiple layers are connected to the layers above and below at prescribed locations if necessary.
  • the insulating layer 60 is provided on the front surface of the semiconductor layer 72 to fill between the metal interconnect layers 50 a to 50 d.
  • the insulating layer 60 may be, for example, a SiO x film, a SiN x film, a low relative dielectric constant (low k) film, etc.
  • a film (an electromagnetic shield film) 24 that includes a metal nitride thin film or a metal thin film covers a portion of the upper surface or the entire upper surface of the light receiving unit 20 with the insulating layer 60 interposed and is grounded via one of the metal interconnect layers 50 .
  • the anode or the cathode (in FIG. 2 , the p + -type anode) of the light receiving element 10 also is grounded.
  • the electromagnetic shield effect can be increased.
  • FIG. 3A is a graph showing the dependence of the transmittance on the thickness of the electromagnetic shield film; and FIG. 3B is a graph showing the sheet resistance for the reciprocal of the thickness of the electromagnetic shield film.
  • the electromagnetic shield film is a metal nitride thin film made of TiN.
  • the vertical axis is the transmittance (%) of near-infrared light of 770 nm; and the horizontal axis is the thickness (nm) of the TiN film.
  • the transmittance decreases to 50% when the film thickness is about 12 nm; and the transmittance decreases to 10% when the film thickness is about 40 nm.
  • the vertical axis is the sheet resistance ( ⁇ /sq.); and the horizontal axis is the reciprocal (1/nm) of the film thickness.
  • the electromagnetic shield effect increases as the sheet resistance decreases.
  • the sheet resistance can be 350 ⁇ /sq. or less by setting the film thickness to be 5 nm or more.
  • the electromagnetic shield film can be used in the light receiving element while maintaining a high transmittance of about 75%.
  • the sensitivity of the light receiving unit 20 decreases when the transmittance is lower than 30%.
  • the film thickness it is favorable for the film thickness to be 21 nm or less and the transmittance to be 30% or more (within the applicable range shown in FIG. 3A ).
  • the sheet resistance can be low, i.e., about 85 ⁇ /sq.; and a high electromagnetic shield effect can be maintained.
  • the metal nitride thin film is not limited to TiN and may be TaN, ZrN, VN, NbN, etc. At 20° C., the resistivity value is 21.7 ⁇ cm for TiN, 135 ⁇ cm for TaN, 13.6 ⁇ cm for ZrN, 200 ⁇ cm for VN, and 200 ⁇ cm for NbN.
  • such metal nitride thin films can be used as a barrier layer that separates the metal interconnect layers from the Si to suppress the diffusion and/or migration of the metal. In other words, it is easy to use the metal nitride thin film in the manufacturing processes of the integrated circuit; and the productivity of the light receiving element 10 can be increased.
  • a metal thin film of Ti, Ta, W, Co, Ni, Al, Cu, etc. may be used as the electromagnetic shield film 24 .
  • a transparent conductive film such as ITO (Indium Tin Oxide), a polycrystalline Si film, a mesh metal film, or the like is used as the electromagnetic shield film.
  • ITO Indium Tin Oxide
  • the suitability for mass production degrades because a dedicated apparatus must be provided offline because the ITO film formation process is different from the manufacturing processes of the integrated circuit.
  • the reliability of ITO is insufficient because film breakage occurs easily at stepped portions. Further, the pattern dimensional precision and the patterning reproducibility are insufficient.
  • the transmittance decreases radically near visible light; and light absorption of near-infrared light also occurs.
  • the sheet resistance becomes high; and the wavelength dependence of the transmittance increases due to the high refractive index.
  • the film formation process of polycrystalline Si may exceed 500° C.; and it is difficult to form the polycrystalline Si on the metal interconnect layer.
  • the electromagnetic shield effect decreases drastically if the openings are too large; and if the mesh is fine, the sensitivity of the light receiving element is reduced because the incident light is reflected. Also, the suitability for mass production of the mesh formation process is insufficient.
  • FIG. 4 is a schematic cross-sectional view of an optically coupled insulating device including the light receiving element of the first embodiment.
  • the optically coupled insulating device (including photocouplers and photorelays) 80 includes the light receiving element 10 of the first embodiment and a light emitting element 84 that is electrically insulated from the light receiving element 10 and irradiates near-infrared light toward the light receiving unit 20 .
  • a signal output unit i.e., an output lead 83
  • the light emitting element 84 is provided on a signal input unit, i.e., an input lead 82
  • an inner resin layer 86 and an outer resin layer 87 may be further provided around the light emitting element 84 and the light receiving element 10 which oppose each other.
  • the light receiving element and the light emitting element may be provided on an insulating substrate and sealed with a resin layer.
  • FIG. 5A is a schematic view showing a measurement system of the instantaneous common mode rejection voltage of the optically coupled insulating device; and FIG. 5B is a waveform diagram showing the change of the pulse voltage.
  • the input lead 82 (the light emitting element 84 side) is insulated from the output lead 83 (the light receiving element 10 side). Therefore, there is a stray capacitance between the input lead 82 and the output lead 83 .
  • V CM pulse voltage
  • V CM common mode noise immunity
  • a high CMR means that the noise immunity is high.
  • the CMR is measured as the change of the output voltage Vo of the light receiving element 10 when the pulse voltage V CM that changes abruptly is applied between an input lead 82 a and an output lead 83 a in a state in which a power supply voltage Vcc is supplied.
  • the CMR is defined by the voltage slope (kV/ ⁇ s) of the maximum pulse voltage V CM for which the change of the output voltage Vo is not more than a prescribed value.
  • the electromagnetic shield film 24 has a thickness of 21 nm, a CMR that is 10 kV/ ⁇ s or more is possible.
  • FIG. 6 is a schematic cross-sectional view of a light receiving element according to a second embodiment.
  • the electromagnetic shield film 24 that is made of the TiN thin film, etc., is connected to the output lead (the grounding side) 83 a of the optically coupled insulating device via the metal interconnect layer 50 d. Also, one terminal of the light receiving unit 20 and the grounding terminal of the signal processing circuit unit 30 are connected to the output lead 83 a .
  • the input terminal of the TIA amplifier 32 that is provided in the front end of the light receiving element 10 as shown in FIG. 5A is connected to the other terminal of the light receiving unit 20 .
  • the insulating layer 60 is interposed and a stray capacitance Cns occurs between the electromagnetic shield film 24 and the cathode (the n-type diffusion layer) of the photodiode included in the light receiving unit 20 .
  • the stray capacitance Cns is unfavorable because the stray capacitance Cns increases the capacitance of the input terminal of the TIA amplifier 32 and causes the frequency characteristics and/or the noise characteristics to degrade. Therefore, it is favorable for the distance between the electromagnetic shield film 24 and the semiconductor layer 72 to be long. For example, the distance is set to be 1 ⁇ m or more.
  • the stray capacitance Cns is reduced by providing the electromagnetic shield film 24 at a position between the metal interconnect layer 50 d, which is the uppermost layer, and the metal interconnect layer that is adjacent to the metal interconnect layer 50 d.
  • the misoperations of the optically coupled insulating device 80 for which the electromagnetic shield effect is increased by the electromagnetic shield film 24 can be reduced further by the signal processing circuit unit 30 being a differential circuit unit.
  • FIG. 7 is a schematic cross-sectional view of a modification of the light receiving element of the second embodiment.
  • the electromagnetic shield film 24 that is made of TiN, etc., is connected to the upper surface of a top layer of the plurality of interconnect layers 50 by contacting the top layer.
  • the top layer is a most distal layer of the plurality of interconnect layers 50 to the semiconductor layer. Therefore, it is unnecessary to provide a through-hole between the metal interconnect layer 50 d and the electromagnetic shield film 24 in the interior of the insulating layer 60 ; and the stray capacitance Cns can be reduced.
  • the substrate of the light receiving element 10 is not limited to the p-type substrate and may be an n-type substrate.
  • the metal interconnect layers 50 may be a metal such as Al, Cu, Ti, etc.
  • FIGS. 8A to 8F are schematic views showing manufacturing processes of the electromagnetic shield film 24 including the metal nitride thin film.
  • FIG. 8A shows the metal interconnect layer 50 d of the uppermost layer of the multiple metal interconnect layers.
  • FIGS. 8A to 8F the metal interconnect layers that are positioned between the semiconductor layer and the metal interconnect layer 50 d which is the uppermost layer are not shown.
  • FIG. 8B is a schematic cross-sectional view of a structure in which a photoresist 90 is patterned
  • FIG. 8C is a schematic cross-sectional view of a structure in which the metal interconnect layer is selectively removed;
  • FIG. 8A shows the metal interconnect layer 50 d of the uppermost layer of the multiple metal interconnect layers.
  • FIGS. 8A to 8F the metal interconnect layers that are positioned between the semiconductor layer and the metal interconnect layer 50 d which is the uppermost layer are not shown.
  • FIG. 8B is a schematic cross-sectional view of a structure in which
  • FIG. 8D is a schematic cross-sectional view of a structure in which a metal nitride thin film is provided;
  • FIG. 8E is a schematic cross-sectional view of a structure in which a photoresist 91 is patterned;
  • FIG. 8F is a schematic cross-sectional view of a structure in which the metal nitride thin film is removed from the outer region of the light receiving unit.
  • the electromagnetic shield film 24 is TiN. Although the electromagnetic shield film 24 is provided on the metal interconnect layer 50 d of the uppermost layer to contact the metal interconnect layer 50 d of the uppermost layer, it is unnecessary for the layer contacted by the electromagnetic shield film 24 to be the uppermost layer.
  • the metal interconnect layer 50 d is formed above the semiconductor layer 72 in which the light receiving unit 20 and the signal processing circuit unit 30 are provided.
  • Thin barrier layers 51 and 52 are provided on two sides of the metal interconnect layer 50 d.
  • the barrier layers 51 and 52 may be TiN (e.g., having thicknesses of 10 to 30 nm).
  • the barrier layer 51 can suppress migration of the metal interconnect layer 50 d; and the barrier layer 52 can prevent reflections in the exposure process.
  • the photoresist 90 is patterned to make openings to at least the upper portion of the front surface of the light receiving unit 20 .
  • FIG. 8C at least the metal interconnect layer 50 d and the barrier layers 51 and 52 on the two sides of the metal interconnect layer 50 d above the light receiving unit 20 are removed; and the photoresist 90 also is removed.
  • a portion of the metal interconnect layer 50 d and the barrier layer 52 in the region around the light receiving unit 20 also is removed.
  • the electromagnetic shield (TiN) film 24 having a thickness of 4 to 20 nm, etc., is formed on a portion of the barrier layer 52 on the metal interconnect layer 50 d and above the light receiving unit 20 by sputtering, etc.
  • the insulating layer 60 may remain above the light receiving unit 20 .
  • the photoresist 91 is patterned to cover the region above the light receiving unit 20 .
  • the structure of FIG. 8F is obtained by removing the electromagnetic shield (TiN) film 24 that is in the region not covered with the photoresist 91 by RIE (Reactive Ion Etching), etc., and by further removing the photoresist 91 .
  • the electromagnetic shield film 24 that is above the light receiving unit 20 is connected to the metal interconnect layer 50 d via the barrier layer 52 remaining at the end portion vicinity of the light receiving unit 20 . It is possible to improve the suitability for mass production of the light receiving element 10 because the electromagnetic shield film 24 including TiN is used as the barrier layer of the semiconductor device, etc.
  • FIGS. 9A to 9F are schematic views showing a modification of the manufacturing processes of the electromagnetic shield film including the metal nitride thin film.
  • FIG. 9A is a schematic cross-sectional view of a structure in which a first metal interconnect layer is provided above the semiconductor layer
  • FIG. 9B is a schematic cross-sectional view of a structure in which the photoresist 90 is patterned
  • FIG. 9C is a schematic cross-sectional view of a structure in which the metal interconnect layer 50 d is selectively removed
  • FIG. 9D is a schematic cross-sectional view of a structure in which an electromagnetic shield film is provided
  • FIG. 9E is a schematic cross-sectional view of a structure in which the photoresist 91 is patterned
  • FIG. 9A is a schematic cross-sectional view of a structure in which a first metal interconnect layer is provided above the semiconductor layer
  • FIG. 9B is a schematic cross-sectional view of a structure in which the photoresist 90 is patterned
  • 9F is a schematic cross-sectional view of a structure in which the electromagnetic shield film 24 is selectively removed. Similarly to FIGS. 8A to 8F , the metal interconnect layers that are positioned between the semiconductor layer and the metal interconnect layer 50 d which is the uppermost layer are not shown. Further, the metal interconnect layer is not limited to being the uppermost layer.
  • the upper portion of the metal interconnect layer 50 d and the barrier layer 52 under the TiN may be removed with the TiN.
  • the photoresist 91 in the modification as shown in FIG. 9E the metal interconnect layer 50 d, the barrier layers 51 and 52 , and the TiN are etched by a continuous process using the same photoresist pattern. Therefore, a portion of the metal interconnect layer 50 d and the barrier layer 52 is not removed and can be used as the metal interconnect layer.
  • the TiN thin film is not provided on the side surface of the metal interconnect layer 50 d to be irradiated with the ion beam used in the RIE. Therefore, the yield decrease due to dust made of the TiN, etc., peeling from the side surface and soiling the interior of the RIE apparatus is suppressed.
  • a light receiving element in which the effects of the noise are reduced and the suitability for mass production is good.
  • the optically coupled insulating device including the light receiving element for example, it is easy for the CMR to be 1 kV/ ⁇ s or more and for misoperations to be suppressed.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • Health & Medical Sciences (AREA)
  • Toxicology (AREA)
  • Light Receiving Elements (AREA)
  • Photo Coupler, Interrupter, Optical-To-Optical Conversion Devices (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)

Abstract

A light receiving element includes: a semiconductor layer; an insulating layer; an interconnect layer; and a film. The semiconductor layer includes a light receiving unit configured to convert a signal light incident on the light receiving unit into an electrical signal. The insulating layer is provided on the semiconductor layer. The interconnect layer is provided on the insulating layer. The film is provided on the insulating layer to cover the light receiving unit and be connected to the interconnect layer, the film being made of a metal or a metal nitride.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • This application is a continuation of application Ser. No. 14/203,114, filed on Mar. 10, 2014 which is based upon and claims the benefit of priority from Japanese Patent Application No. 2013-190503, filed on Sep. 13, 2013, the entire contents of each are incorporated herein by reference.
    • FIELD
  • Embodiments described herein relate generally a light receiving element and an optically coupled insulating device.
    • BACKGROUND
  • In many industrial electronic devices, communication devices, and the like, different power supply systems such as an AC power supply system, a DC power supply system, a telephone line system, etc., are disposed inside the same device to transmit an electrical signal.
  • In such a case, operations can be stable and safety can be ensured by using an optically coupled insulating device that can transmit the electrical signal in a state in which the input circuit and the output circuit are insulated from each other.
  • When a high voltage of 1 kV or more is applied between the input terminal and the output terminal of such an optically coupled insulating device, a noise component may occur in the light receiving element due to the electrostatic capacitance of an insulating layer between the input terminal and the output terminal.
  • Such noise can be reduced by covering the light receiving element with an electromagnetic shield film made of ITO (Indium Tin Oxide), a metal thin film having a mesh configuration, etc. However, it is difficult to improve the suitability for mass production of such an electromagnetic shield film in the manufacturing processes of the light receiving element.
    • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a schematic plan view of a light receiving element according to a first embodiment;
  • FIG. 2 is a schematic cross-sectional view of the light receiving element along line A-A of the light receiving element of the first embodiment;
  • FIG. 3A is a graph showing the dependence of the transmittance on the thickness of the electromagnetic shield film; and FIG. 3B is a graph showing the sheet resistance for the reciprocal of the thickness of the electromagnetic shield film;
  • FIG. 4 is a schematic cross-sectional view of an optically coupled insulating device including the light receiving element of the first embodiment;
  • FIG. 5A is a schematic view showing a measurement system of the instantaneous common mode rejection voltage of the optically coupled insulating device; and FIG. 5B is a waveform diagram showing the change of the pulse voltage;
  • FIG. 6 is a schematic cross-sectional view of a light receiving element according to a second embodiment;
  • FIG. 7 is a schematic cross-sectional view of a modification of the light receiving element of the second embodiment;
  • FIGS. 8A to 8F are schematic views showing manufacturing processes of the electromagnetic shield film 24 including the metal nitride thin film; and
  • FIGS. 9A to 9F are schematic views showing a modification of the manufacturing processes of the electromagnetic shield film including the metal nitride thin film.
    •  DETAILED DESCRIPTION
  • In general, according to one embodiment, a light receiving element includes: a semiconductor layer; an insulating layer; an interconnect layer; and a film. The semiconductor layer includes a light receiving unit configured to convert a signal light incident on the light receiving unit into an electrical signal. The insulating layer is provided on the semiconductor layer. The interconnect layer is provided on the insulating layer. The film is provided on the insulating layer to cover the light receiving unit and be connected to the interconnect layer, the film being made of a metal or a metal nitride.
  • Embodiments of the invention will now be described with reference to the drawings.
  • FIG. 1 is a schematic plan view of a light receiving element according to a first embodiment.
  • The light receiving element 10 includes a semiconductor substrate, a semiconductor layer provided on the semiconductor substrate, a metal interconnect layer, an insulating layer, and an electromagnetic shield film including a metal nitride thin film or a metal thin film.
  • The semiconductor layer includes a light receiving unit 20 that converts a signal light incident on the light receiving unit 20 into an electrical signal. The length of one side of one unit of the photodiodes included in the light receiving unit 20 may be 20 to 200 μm, etc.; and the units may be disposed in an array configuration or a mosaic array configuration.
  • The semiconductor layer may further include a signal processing circuit unit that processes and outputs the electrical signal. The signal processing circuit unit includes a TIA (a Transimpedance Amp) 32, a comparator 34, an output circuit 36, a current source 38, an amplifier bias circuit 40, etc. Also, the light receiving element 10 may include electrode pad units 42 to 46, etc.
  • FIG. 2 is a schematic cross-sectional view of the light receiving element along line A-A of the light receiving element of the first embodiment.
  • A semiconductor substrate 70 may be, for example, Si, SiC, etc. A semiconductor layer 72 that includes Si, etc., is provided on the semiconductor substrate 70 to include the light receiving unit 20 that converts a signal light Lin incident on the light receiving unit 20 into the electrical signal, and the signal processing circuit unit that processes and outputs the electrical signal. For example, the semiconductor substrate 70 is the p+-type; and an n-type layer is provided on the semiconductor substrate 70. For example, a p+-type layer 72 a is formed by ion implantation, etc., from the front surface side to reach the semiconductor substrate 70 to separate the light receiving unit 20 from the signal processing circuit unit.
  • P-type layers and/or n-type layers are provided in the semiconductor layer 72 to form the signal processing circuit unit by forming MOS transistors and/or bipolar transistors. The light receiving unit 20 includes a high-resistance n-type layer 72 b, a p+-type layer 72 c, an n+-type layer 72 d, etc. The conductivity types of the regions of the semiconductor substrate 70 and the semiconductor layer 72 may be the opposite of those of the structure of FIG. 2.
  • Metal interconnect layers 50 are provided at the upper portion of the semiconductor layer 72 to be connected respectively to the light receiving unit 20 and a signal processing circuit unit 30. In the case of metal interconnect layers 50 a to 50 d in which a plurality of layers are stacked with an insulating layer 60 interposed, the multiple layers are connected to the layers above and below at prescribed locations if necessary.
  • The insulating layer 60 is provided on the front surface of the semiconductor layer 72 to fill between the metal interconnect layers 50 a to 50 d. The insulating layer 60 may be, for example, a SiOx film, a SiNx film, a low relative dielectric constant (low k) film, etc.
  • A film (an electromagnetic shield film) 24 that includes a metal nitride thin film or a metal thin film covers a portion of the upper surface or the entire upper surface of the light receiving unit 20 with the insulating layer 60 interposed and is grounded via one of the metal interconnect layers 50. On the other hand, the anode or the cathode (in FIG. 2, the p+-type anode) of the light receiving element 10 also is grounded. Thus, the electromagnetic shield effect can be increased.
  • FIG. 3A is a graph showing the dependence of the transmittance on the thickness of the electromagnetic shield film; and FIG. 3B is a graph showing the sheet resistance for the reciprocal of the thickness of the electromagnetic shield film.
  • In FIGS. 3A and 3B, the electromagnetic shield film is a metal nitride thin film made of TiN. In FIG. 3A, the vertical axis is the transmittance (%) of near-infrared light of 770 nm; and the horizontal axis is the thickness (nm) of the TiN film. The transmittance decreases to 50% when the film thickness is about 12 nm; and the transmittance decreases to 10% when the film thickness is about 40 nm.
  • In FIG. 3B, the vertical axis is the sheet resistance (Ω/sq.); and the horizontal axis is the reciprocal (1/nm) of the film thickness. The electromagnetic shield effect increases as the sheet resistance decreases. By the evaluation of the common mode noise immunity described in detail below, the inventors discovered that misoperations due to the noise occurring due to a pulse voltage slope of 1 kV/μs can be reduced by setting the sheet resistance to be 350 Ω/sq. or less (within the applicable range shown in FIG. 3B). In the case of TiN, the sheet resistance can be 350 Ω/sq. or less by setting the film thickness to be 5 nm or more. In such a case, the electromagnetic shield film can be used in the light receiving element while maintaining a high transmittance of about 75%.
  • On the other hand, the sensitivity of the light receiving unit 20 decreases when the transmittance is lower than 30%. In other words, it is favorable for the film thickness to be 21 nm or less and the transmittance to be 30% or more (within the applicable range shown in FIG. 3A). In the case where the film thickness is 21 nm, the sheet resistance can be low, i.e., about 85 Ω/sq.; and a high electromagnetic shield effect can be maintained.
  • The metal nitride thin film is not limited to TiN and may be TaN, ZrN, VN, NbN, etc. At 20° C., the resistivity value is 21.7 μΩ·cm for TiN, 135 μΩ·cm for TaN, 13.6 μΩ·cm for ZrN, 200 μ·cm for VN, and 200 μΩ·cm for NbN. In the case of Si, such metal nitride thin films can be used as a barrier layer that separates the metal interconnect layers from the Si to suppress the diffusion and/or migration of the metal. In other words, it is easy to use the metal nitride thin film in the manufacturing processes of the integrated circuit; and the productivity of the light receiving element 10 can be increased. Further, a metal thin film of Ti, Ta, W, Co, Ni, Al, Cu, etc., may be used as the electromagnetic shield film 24.
  • On the other hand, there are structures in which a transparent conductive film such as ITO (Indium Tin Oxide), a polycrystalline Si film, a mesh metal film, or the like is used as the electromagnetic shield film. In the case where ITO is used, the suitability for mass production degrades because a dedicated apparatus must be provided offline because the ITO film formation process is different from the manufacturing processes of the integrated circuit. Moreover, the reliability of ITO is insufficient because film breakage occurs easily at stepped portions. Further, the pattern dimensional precision and the patterning reproducibility are insufficient.
  • In the case of a polycrystalline Si film, the transmittance decreases radically near visible light; and light absorption of near-infrared light also occurs. In the case where the thickness is reduced to reduce the light absorption, the sheet resistance becomes high; and the wavelength dependence of the transmittance increases due to the high refractive index. Further, the film formation process of polycrystalline Si may exceed 500° C.; and it is difficult to form the polycrystalline Si on the metal interconnect layer.
  • In the case of a mesh metal film, the electromagnetic shield effect decreases drastically if the openings are too large; and if the mesh is fine, the sensitivity of the light receiving element is reduced because the incident light is reflected. Also, the suitability for mass production of the mesh formation process is insufficient.
  • Thus, the reliability and suitability for mass production are insufficient for an electromagnetic shield film made of a transparent conductive film, a polycrystalline Si film, or a mesh metal film. Conversely, it is easy to improve the characteristics and suitability for mass production of an electromagnetic shield film made of a metal nitride thin film.
  • FIG. 4 is a schematic cross-sectional view of an optically coupled insulating device including the light receiving element of the first embodiment.
  • The optically coupled insulating device (including photocouplers and photorelays) 80 includes the light receiving element 10 of the first embodiment and a light emitting element 84 that is electrically insulated from the light receiving element 10 and irradiates near-infrared light toward the light receiving unit 20. If the light receiving element 10 is provided on a signal output unit, i.e., an output lead 83, and the light emitting element 84 is provided on a signal input unit, i.e., an input lead 82, an inner resin layer 86 and an outer resin layer 87 may be further provided around the light emitting element 84 and the light receiving element 10 which oppose each other. The light receiving element and the light emitting element may be provided on an insulating substrate and sealed with a resin layer.
  • FIG. 5A is a schematic view showing a measurement system of the instantaneous common mode rejection voltage of the optically coupled insulating device; and FIG. 5B is a waveform diagram showing the change of the pulse voltage.
  • In the optically coupled insulating device 80, the input lead 82 (the light emitting element 84 side) is insulated from the output lead 83 (the light receiving element 10 side). Therefore, there is a stray capacitance between the input lead 82 and the output lead 83. When a pulse voltage VCM that changes abruptly is applied between the input and output leads, a displacement current flows; and noise that causes misoperations occurs in an output voltage Vo of the light receiving element 10. The instantaneous common mode rejection voltage can be expressed as the common mode noise immunity (CMR (Common Mode Rejection)). In other words, a high CMR means that the noise immunity is high.
  • The CMR is measured as the change of the output voltage Vo of the light receiving element 10 when the pulse voltage VCM that changes abruptly is applied between an input lead 82 a and an output lead 83 a in a state in which a power supply voltage Vcc is supplied. In other words, the CMR is defined by the voltage slope (kV/μs) of the maximum pulse voltage VCM for which the change of the output voltage Vo is not more than a prescribed value. For example, in the case where the electromagnetic shield film 24 has a thickness of 21 nm, a CMR that is 10 kV/μs or more is possible.
  • FIG. 6 is a schematic cross-sectional view of a light receiving element according to a second embodiment.
  • The electromagnetic shield film 24 that is made of the TiN thin film, etc., is connected to the output lead (the grounding side) 83 a of the optically coupled insulating device via the metal interconnect layer 50 d. Also, one terminal of the light receiving unit 20 and the grounding terminal of the signal processing circuit unit 30 are connected to the output lead 83 a. For example, the input terminal of the TIA amplifier 32 that is provided in the front end of the light receiving element 10 as shown in FIG. 5A is connected to the other terminal of the light receiving unit 20.
  • In FIG. 6, the insulating layer 60 is interposed and a stray capacitance Cns occurs between the electromagnetic shield film 24 and the cathode (the n-type diffusion layer) of the photodiode included in the light receiving unit 20. The stray capacitance Cns is unfavorable because the stray capacitance Cns increases the capacitance of the input terminal of the TIA amplifier 32 and causes the frequency characteristics and/or the noise characteristics to degrade. Therefore, it is favorable for the distance between the electromagnetic shield film 24 and the semiconductor layer 72 to be long. For example, the distance is set to be 1 μm or more. In FIG. 6, the stray capacitance Cns is reduced by providing the electromagnetic shield film 24 at a position between the metal interconnect layer 50 d, which is the uppermost layer, and the metal interconnect layer that is adjacent to the metal interconnect layer 50 d.
  • The misoperations of the optically coupled insulating device 80 for which the electromagnetic shield effect is increased by the electromagnetic shield film 24 can be reduced further by the signal processing circuit unit 30 being a differential circuit unit.
  • FIG. 7 is a schematic cross-sectional view of a modification of the light receiving element of the second embodiment.
  • The electromagnetic shield film 24 that is made of TiN, etc., is connected to the upper surface of a top layer of the plurality of interconnect layers 50 by contacting the top layer. The top layer is a most distal layer of the plurality of interconnect layers 50 to the semiconductor layer. Therefore, it is unnecessary to provide a through-hole between the metal interconnect layer 50 d and the electromagnetic shield film 24 in the interior of the insulating layer 60; and the stray capacitance Cns can be reduced. The substrate of the light receiving element 10 is not limited to the p-type substrate and may be an n-type substrate. Also, the metal interconnect layers 50 may be a metal such as Al, Cu, Ti, etc.
  • FIGS. 8A to 8F are schematic views showing manufacturing processes of the electromagnetic shield film 24 including the metal nitride thin film. Namely, FIG. 8A shows the metal interconnect layer 50 d of the uppermost layer of the multiple metal interconnect layers. In FIGS. 8A to 8F, the metal interconnect layers that are positioned between the semiconductor layer and the metal interconnect layer 50 d which is the uppermost layer are not shown. FIG. 8B is a schematic cross-sectional view of a structure in which a photoresist 90 is patterned; FIG. 8C is a schematic cross-sectional view of a structure in which the metal interconnect layer is selectively removed; FIG. 8D is a schematic cross-sectional view of a structure in which a metal nitride thin film is provided; FIG. 8E is a schematic cross-sectional view of a structure in which a photoresist 91 is patterned; and FIG. 8F is a schematic cross-sectional view of a structure in which the metal nitride thin film is removed from the outer region of the light receiving unit.
  • In these drawings, the electromagnetic shield film 24 is TiN. Although the electromagnetic shield film 24 is provided on the metal interconnect layer 50 d of the uppermost layer to contact the metal interconnect layer 50 d of the uppermost layer, it is unnecessary for the layer contacted by the electromagnetic shield film 24 to be the uppermost layer.
  • As shown in FIG. 8A, the metal interconnect layer 50 d is formed above the semiconductor layer 72 in which the light receiving unit 20 and the signal processing circuit unit 30 are provided. Thin barrier layers 51 and 52 are provided on two sides of the metal interconnect layer 50 d. In the case where the metal interconnect layers 50 are Al (e.g., having thicknesses of 200 to 1500 nm), the barrier layers 51 and 52 may be TiN (e.g., having thicknesses of 10 to 30 nm). The barrier layer 51 can suppress migration of the metal interconnect layer 50 d; and the barrier layer 52 can prevent reflections in the exposure process.
  • As shown in FIG. 8B, the photoresist 90 is patterned to make openings to at least the upper portion of the front surface of the light receiving unit 20. Continuing as shown in FIG. 8C, at least the metal interconnect layer 50 d and the barrier layers 51 and 52 on the two sides of the metal interconnect layer 50 d above the light receiving unit 20 are removed; and the photoresist 90 also is removed. In these drawings, a portion of the metal interconnect layer 50 d and the barrier layer 52 in the region around the light receiving unit 20 also is removed.
  • Then, as shown in FIG. 8D, the electromagnetic shield (TiN) film 24 having a thickness of 4 to 20 nm, etc., is formed on a portion of the barrier layer 52 on the metal interconnect layer 50 d and above the light receiving unit 20 by sputtering, etc. The insulating layer 60 may remain above the light receiving unit 20.
  • Continuing as shown in FIG. 8E, the photoresist 91 is patterned to cover the region above the light receiving unit 20. The structure of FIG. 8F is obtained by removing the electromagnetic shield (TiN) film 24 that is in the region not covered with the photoresist 91 by RIE (Reactive Ion Etching), etc., and by further removing the photoresist 91. The electromagnetic shield film 24 that is above the light receiving unit 20 is connected to the metal interconnect layer 50 d via the barrier layer 52 remaining at the end portion vicinity of the light receiving unit 20. It is possible to improve the suitability for mass production of the light receiving element 10 because the electromagnetic shield film 24 including TiN is used as the barrier layer of the semiconductor device, etc.
  • FIGS. 9A to 9F are schematic views showing a modification of the manufacturing processes of the electromagnetic shield film including the metal nitride thin film. Namely, FIG. 9A is a schematic cross-sectional view of a structure in which a first metal interconnect layer is provided above the semiconductor layer; FIG. 9B is a schematic cross-sectional view of a structure in which the photoresist 90 is patterned; FIG. 9C is a schematic cross-sectional view of a structure in which the metal interconnect layer 50 d is selectively removed; FIG. 9D is a schematic cross-sectional view of a structure in which an electromagnetic shield film is provided; FIG. 9E is a schematic cross-sectional view of a structure in which the photoresist 91 is patterned; and FIG. 9F is a schematic cross-sectional view of a structure in which the electromagnetic shield film 24 is selectively removed. Similarly to FIGS. 8A to 8F, the metal interconnect layers that are positioned between the semiconductor layer and the metal interconnect layer 50 d which is the uppermost layer are not shown. Further, the metal interconnect layer is not limited to being the uppermost layer.
  • In the case where the electromagnetic shield film 24 that is made of TiN is removed by RIE, etc., the upper portion of the metal interconnect layer 50 d and the barrier layer 52 under the TiN may be removed with the TiN. By patterning the photoresist 91 in the modification as shown in FIG. 9E, the metal interconnect layer 50 d, the barrier layers 51 and 52, and the TiN are etched by a continuous process using the same photoresist pattern. Therefore, a portion of the metal interconnect layer 50 d and the barrier layer 52 is not removed and can be used as the metal interconnect layer.
  • Because there is no process to form the TiN thin film on the side surface of the metal interconnect layer 50 d, the TiN thin film is not provided on the side surface of the metal interconnect layer 50 d to be irradiated with the ion beam used in the RIE. Therefore, the yield decrease due to dust made of the TiN, etc., peeling from the side surface and soiling the interior of the RIE apparatus is suppressed.
  • According to the embodiment, a light receiving element is provided in which the effects of the noise are reduced and the suitability for mass production is good. According to the optically coupled insulating device including the light receiving element, for example, it is easy for the CMR to be 1 kV/μs or more and for misoperations to be suppressed. While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modification as would fall within the scope and spirit of the inventions.

Claims (11)

What is claimed is:
1. A light receiving element, comprising:
a semiconductor layer including a light receiving portion;
an insulating layer provided on the semiconductor layer;
an interconnect layer provided on the insulating layer; and
a film provided on the insulating layer to cover the light receiving portion and be connected to the interconnect layer, wherein
the film is a metal or a metal nitride including at least one selected from Ti, Ta, Zr, V and Nb.
2. The element according to claim 1, wherein the interconnect layer includes layers, a part of the insulating layer being provided between the layers.
3. The element according to claim 2, wherein the layers are connected at a prescribed location.
4. The element according to claim 2, wherein the film is connected to an upper surface of a top layer of the layers.
5. The element according to claim 4, wherein the film is provided to contact a portion of the upper surface of the top layer.
6. The element according to claim 2, wherein the film is provided to contact at least one of the layers.
7. The element according to claim 1, wherein
the light receiving unit includes an anode and a cathode, and
the film is connected to the anode or the cathode via the interconnect layer.
8. The element according to claim 1, wherein
the semiconductor layer further includes a signal processing circuit unit connected to the light receiving portion to process and output the electrical signal, and
the film is connected to a ground of the signal processing circuit unit via the interconnect layer.
9. The element according to claim 1, wherein the film has a thickness of not more than 21 nm.
10. An optically coupled insulating device, comprising:
a light receiving element including a semiconductor layer, an insulating layer, an interconnect layer, and a film, the semiconductor layer including a light receiving portion, the insulating layer being provided on the semiconductor layer, the interconnect layer being provided on the insulating layer, the film being provided on the insulating layer to cover the light receiving portion and be connected to the interconnect layer, wherein the film is a metal or a metal nitride including at least one selected from Ti, Ta, Zr, V and Nb;
a light emitting element configured to irradiate the signal light toward the light receiving portion;
a signal input unit, the light emitting element being provided on the signal input unit; and
an output unit insulated from the signal input unit, the light receiving element being provided on the output unit.
11. The device according to claim 10, wherein the film has a thickness of not more than 21 nm.
US14/852,084 2013-09-13 2015-09-11 Shielding film for a light receiving element and optically coupled insulating device Abandoned US20150380594A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US14/852,084 US20150380594A1 (en) 2013-09-13 2015-09-11 Shielding film for a light receiving element and optically coupled insulating device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP2013-190503 2013-09-13
JP2013190503A JP5956968B2 (en) 2013-09-13 2013-09-13 Light receiving element and optically coupled signal isolator
US14/203,114 US9379272B2 (en) 2013-09-13 2014-03-10 Light receiving element and optically coupled insulating device
US14/852,084 US20150380594A1 (en) 2013-09-13 2015-09-11 Shielding film for a light receiving element and optically coupled insulating device

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US14/203,114 Continuation US9379272B2 (en) 2013-09-13 2014-03-10 Light receiving element and optically coupled insulating device

Publications (1)

Publication Number Publication Date
US20150380594A1 true US20150380594A1 (en) 2015-12-31

Family

ID=52667162

Family Applications (2)

Application Number Title Priority Date Filing Date
US14/203,114 Active US9379272B2 (en) 2013-09-13 2014-03-10 Light receiving element and optically coupled insulating device
US14/852,084 Abandoned US20150380594A1 (en) 2013-09-13 2015-09-11 Shielding film for a light receiving element and optically coupled insulating device

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US14/203,114 Active US9379272B2 (en) 2013-09-13 2014-03-10 Light receiving element and optically coupled insulating device

Country Status (2)

Country Link
US (2) US9379272B2 (en)
JP (1) JP5956968B2 (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW201637190A (en) * 2015-03-25 2016-10-16 Sony Corp Solid-state imaging device and electronic apparatus
WO2018020902A1 (en) * 2016-07-27 2018-02-01 ソニーセミコンダクタソリューションズ株式会社 Solid-state image pickup element and electronic device
JP2020113602A (en) * 2019-01-09 2020-07-27 株式会社東芝 Semiconductor device
CN117501459A (en) * 2021-06-14 2024-02-02 罗姆股份有限公司 Insulation assembly
WO2022264981A1 (en) * 2021-06-14 2022-12-22 ローム株式会社 Insulation module

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20120133010A1 (en) * 2010-11-29 2012-05-31 Kabushiki Kaisha Toshiba Semiconductor device and method of manufacturing the semiconductor device
US8445827B2 (en) * 2009-05-12 2013-05-21 Sony Corporation Multi-wiring layer solid-state imaging device with increased sensitivity, electronic apparatus, and method for manufacturing same
US8946797B2 (en) * 2012-04-02 2015-02-03 Sony Corporation Solid-state imaging device, method of manufacturing solid-state imaging device, apparatus for manufacturing semiconductor device, method of manufacturing semiconductor device, and electronic device
US8987852B2 (en) * 2011-02-09 2015-03-24 Canon Kabushiki Kaisha Solid-state image pickup apparatus, image pickup system including solid-state image pickup apparatus, and method for manufacturing solid-state image pickup apparatus

Family Cites Families (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0350777A (en) * 1989-07-18 1991-03-05 Nec Corp Photocoupler
JPH0369173A (en) * 1989-08-08 1991-03-25 Nec Corp Photocoupler
JP3074685B2 (en) * 1989-09-26 2000-08-07 日本電気株式会社 Light receiving IC
JPH03180077A (en) * 1989-12-08 1991-08-06 Nec Corp Photocoupler
JP3362712B2 (en) * 1990-08-21 2003-01-07 セイコーエプソン株式会社 Semiconductor device, semiconductor memory and CMOS semiconductor integrated circuit using the same, and method of manufacturing the semiconductor device
JPH04106985A (en) 1990-08-27 1992-04-08 Nec Corp Photocoupler
JP2651756B2 (en) 1991-04-24 1997-09-10 シャープ株式会社 Optical semiconductor device
JPH04354379A (en) * 1991-05-31 1992-12-08 Nec Corp Photocoupler
JPH04373181A (en) * 1991-06-21 1992-12-25 Nec Corp Photocoupler
JPH0556916A (en) * 1991-08-30 1993-03-09 Toshiba Corp Solid-state image pickup element module for endoscope
JPH06302988A (en) * 1993-04-19 1994-10-28 Nippon Sheet Glass Co Ltd Electromagnetic wave shielding body
JP3497977B2 (en) 1997-10-27 2004-02-16 シャープ株式会社 Light receiving element and optical coupling device using the same
JP2000340990A (en) * 1999-05-28 2000-12-08 Bridgestone Corp Electromagnetic wave shielding light-transmitting window material and laminated panel affixing material
US6864555B2 (en) * 2001-09-04 2005-03-08 Eugene Robert Worley Photo detector methods to reduce the disabling effects of displacement current in opto-couplers
JP4992446B2 (en) * 2006-02-24 2012-08-08 ソニー株式会社 Solid-state imaging device, manufacturing method thereof, and camera
JP4611255B2 (en) 2006-07-18 2011-01-12 ルネサスエレクトロニクス株式会社 Semiconductor photo detector
US7482646B2 (en) * 2006-10-18 2009-01-27 Hejian Technology (Suzhou) Co., Ltd. Image sensor
CN100517653C (en) * 2006-12-08 2009-07-22 中芯国际集成电路制造(上海)有限公司 Method used for DRAM unit and periphery transistor and its structure produced by the same
JP2008263035A (en) * 2007-04-11 2008-10-30 Sharp Corp Method for manufacturing optical coupling device
JP4609497B2 (en) * 2008-01-21 2011-01-12 ソニー株式会社 Solid-state imaging device, manufacturing method thereof, and camera
TWI622175B (en) 2008-07-31 2018-04-21 半導體能源研究所股份有限公司 Semiconductor device
JP2010040889A (en) 2008-08-07 2010-02-18 Nec Electronics Corp Semiconductor device and inspection method of semiconductor device
JP2010103378A (en) 2008-10-24 2010-05-06 Omron Corp Photosensor
KR101776955B1 (en) * 2009-02-10 2017-09-08 소니 주식회사 Solid-state imaging device, method of manufacturing the same, and electronic apparatus
JP2013016714A (en) * 2011-07-05 2013-01-24 Panasonic Corp Semiconductor photodetector, manufacturing method of the same and semiconductor device
JP6029266B2 (en) * 2011-08-09 2016-11-24 キヤノン株式会社 Imaging device, imaging system, and manufacturing method of imaging device
JP2014053591A (en) * 2012-08-08 2014-03-20 Sony Corp Image pickup element, image pickup device, manufacturing apparatus and method
US10270003B2 (en) * 2012-12-04 2019-04-23 Taiwan Semiconductor Manufacturing Company, Ltd. Method and apparatus for CMOS sensor packaging

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8445827B2 (en) * 2009-05-12 2013-05-21 Sony Corporation Multi-wiring layer solid-state imaging device with increased sensitivity, electronic apparatus, and method for manufacturing same
US20120133010A1 (en) * 2010-11-29 2012-05-31 Kabushiki Kaisha Toshiba Semiconductor device and method of manufacturing the semiconductor device
US8987852B2 (en) * 2011-02-09 2015-03-24 Canon Kabushiki Kaisha Solid-state image pickup apparatus, image pickup system including solid-state image pickup apparatus, and method for manufacturing solid-state image pickup apparatus
US8946797B2 (en) * 2012-04-02 2015-02-03 Sony Corporation Solid-state imaging device, method of manufacturing solid-state imaging device, apparatus for manufacturing semiconductor device, method of manufacturing semiconductor device, and electronic device

Also Published As

Publication number Publication date
JP2015056590A (en) 2015-03-23
US20150076526A1 (en) 2015-03-19
JP5956968B2 (en) 2016-07-27
US9379272B2 (en) 2016-06-28

Similar Documents

Publication Publication Date Title
US20150380594A1 (en) Shielding film for a light receiving element and optically coupled insulating device
CN103890971B (en) Optical detection device
US9709715B2 (en) Spectroscopic sensor and angle limiting filter
KR20120075971A (en) Multi layered photo diode and method for manufacturing the same
KR20170132130A (en) Sensor, manufacturing method thereof and electronic device
US9076904B2 (en) Photo detector device, photo sensor and spectrum sensor
JP2020150161A (en) Photodetector and rider device
CN109196663B (en) Optical sensor
JP6878528B2 (en) Photon detection device, system and manufacturing method
JP2005129689A (en) Semiconductor photo detector and light receiving module
JP5290505B2 (en) Manufacturing method of optical sensor
JP5614540B2 (en) Spectroscopic sensor and angle limiting filter
US20150076525A1 (en) Light receiving element and optically coupled insulating device
JP5642593B2 (en) Back-illuminated semiconductor photo detector, optical receiver module, optical transceiver
US7705414B2 (en) Photoelectric conversion device and image sensor
JP6237803B2 (en) Optical sensor and spectroscopic sensor
JP6079840B2 (en) Spectroscopic sensor and angle limiting filter
JP5804166B2 (en) Spectroscopic sensor and angle limiting filter
JP5900585B2 (en) Optical sensor and spectroscopic sensor
CN116469943A (en) Photosensitive element and photoelectric component
JP2013254770A (en) Photocoupler
JP2013016714A (en) Semiconductor photodetector, manufacturing method of the same and semiconductor device
JP2015038632A (en) Spectrum sensor and angle restriction filter

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO PAY ISSUE FEE