WO2024115046A1 - Optical sensor element, multi-spectral optical sensor and electronic device - Google Patents

Optical sensor element, multi-spectral optical sensor and electronic device Download PDF

Info

Publication number
WO2024115046A1
WO2024115046A1 PCT/EP2023/080850 EP2023080850W WO2024115046A1 WO 2024115046 A1 WO2024115046 A1 WO 2024115046A1 EP 2023080850 W EP2023080850 W EP 2023080850W WO 2024115046 A1 WO2024115046 A1 WO 2024115046A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical sensor
optical
optical filter
sensor element
array
Prior art date
Application number
PCT/EP2023/080850
Other languages
French (fr)
Inventor
Mohsen Mozaffari
Gunter Siess
Original Assignee
ams Sensors Germany GmbH
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 ams Sensors Germany GmbH filed Critical ams Sensors Germany GmbH
Publication of WO2024115046A1 publication Critical patent/WO2024115046A1/en

Links

Classifications

    • 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
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/1462—Coatings
    • H01L27/14621—Colour filter arrangements
    • 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
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/14603—Special geometry or disposition of pixel-elements, address-lines or gate-electrodes
    • H01L27/14605—Structural or functional details relating to the position of the pixel elements, e.g. smaller pixel elements in the center of the imager compared to pixel elements at the periphery
    • 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
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/1462—Coatings
    • 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
    • H01L27/146—Imager structures
    • H01L27/14601—Structural or functional details thereof
    • H01L27/14625—Optical elements or arrangements associated with the device
    • H01L27/14627—Microlenses

Definitions

  • the present disclosure refers to an optical sensor element , a multi-spectral optical sensor and an electronic device .
  • Spectral reconstruction is an important issue to be managed in multi-spectral photography .
  • ef fects of an ambient light source may be compensated using a multi-spectral ambient light sensor (ALS ) which may be used for measuring the spectral information relating to a scene .
  • ALS multi-spectral ambient light sensor
  • Ef forts are being taken to provide improved multi-spectral optical sensors .
  • an optical sensor element comprises a detection region, an optical filter, an adhesive layer between the detection region and a first main surface of the optical filter, the adhesive layer having a thickness of more than 1pm and less than 20 pm, and a microlens over a second main surface of the optical filter .
  • the optical filter is transparent for a visible wavelength range of a certain color .
  • a lateral width of the detection region is smaller than a lateral width of the optical filter .
  • a multi-spectral optical sensor comprises an array of detection regions and an array of optical filters . At least one of the optical filters is transparent for electromagnetic radiation in a first wavelength region, at least a further one of the optical filters is transparent for electromagnetic radiation in a second wavelength region di f ferent from the first wavelength region .
  • the multi- spectral optical sensor further comprises an adhesive layer between the array of detection regions and the array of optical filters , the adhesive layer being adj acent to a first main surface of the optical filters , the adhesive layer having a thickness o f more than 1pm and less than 20 pm and a microlens array over a second main surface of the array of optical filters .
  • the multi-spectral optical sensor may further comprise a peripheral region between adj acent detection regions .
  • an insulating material may be arranged in the peripheral region .
  • wirings may be arranged in the peripheral region .
  • the microlens array may comprise a plurality of microlenses having a rectangular aperture .
  • the microlenses may be arranged to be in contact with adj acent ones of the microlenses .
  • An electronic device comprises the multi-spectral optical sensor as described above .
  • the electronic device may be a mobile phone , a smart phone , a computer, a laptop or a camera .
  • an optical sensor element comprises a detection region, an optical filter arranged over the detection region so that a first main surface of the optical filter is adj acent to the detection region and a microlens directly adj acent to a second main surface of the optical filter .
  • Fig . 1 shows a schematic view of an optical sensor element according to embodiments .
  • Fig . 2A shows a schematic cross-sectional view of a multi- spectral optical sensor according to embodiments .
  • Fig . 2B shows a top view of a multi-spectral optical sensor shown in Fig . 2A.
  • Fig. 3 shows a schematic view of an electronic device according to embodiments.
  • Fig. 4 shows a schematic view of an optical sensor element according to further embodiments.
  • Figs. 5A to 5C show top views of a multi-spectral optical sensor according to embodiments.
  • lateral and horizontal intends to describe an orientation parallel to a first surface of a substrate or semiconductor body. This can be for instance the surface of a wafer or a die.
  • vertical as used in this speci fication intends to describe an orientation which is arranged perpendicular to the first surface of a substrate or semiconductor body .
  • Fig . 1 shows a schematic cross- sectional view of an optical sensor element 10 according to embodiments .
  • the optical sensor element 10 comprises a detection region 105 and an optical filter 108 .
  • An adhesive layer 107 is arranged between the detection region 105 and a first main surface 117 of the optical filter 108 .
  • the adhesive layer 107 has a thickness of more than 1 pm and less than 20 pm .
  • the optical sensor element 10 further comprises a microlens 109 over a second main surface 118 of the optical filter 108 .
  • the optical filter 108 is transparent for a visible wavelength of a certain color .
  • the optical filter 108 may be implemented e . g . by a passband optical interference filter which selectively transmits incoming wavelengths of a certain passband .
  • the interference filter may be implemented by a stack of thin layers arranged .
  • the optical filter 108 may be arranged over a transparent carrier 123 , e . g . a glass carrier .
  • the optical filter 108 may have a thickness of approximately 2 to 5 pm, e . g . approximately 3 pm .
  • the transparent carrier 123 may have a thickness of 100 to 300 pm . As is illustrated in Fig .
  • the optical filter 108 may be arranged on a side of the transparent carrier 123 remote from the detection region 105 and facing the microlens 109 .
  • the first main surface 117 of the optical filter 108 may be arranged adj acent to the transparent carrier 123 .
  • the adhesive layer 107 may be directly adj acent to transparent carrier 123 .
  • the optical filter 108 may be arranged on a side of the transparent carrier 123 facing the dection region 105 . This will be explained with reference to Fig . 2A.
  • the optical filter 108 including the transparent carrier 123 is attached to the detection region 105 by means of a suitable adhesive layer 107 .
  • the adhesive layer 107 is transparent to the electromagnetic radiation transmitted by the optical filter 108 .
  • the adhesive layer may comprise or consist of an epoxy layer .
  • the adhesive may comprise silicones , acrylics , polyimides , depending on the applications intended for the optical sensor .
  • the adhesive layer has a thickness of more than 1 pm and less than 20 pm .
  • a thickness of the adhesive layer may be 7 to 15 pm or 8 to 12 pm .
  • ripple-like interference may occur in transmission which impairs the functionality of the color filter .
  • i f the color filter is configured to transmit longer wavelengths
  • a typical thickness of the adhesive layer 107 may be in a same range as the wavelength . Accordingly, the impact of the interference gets more severe . Further, the ripple-like interference depends on an angle of incidence of light rays on the color filter .
  • microlens refers to a lens having a diameter less than 1 mm, e . g . less than 100 pm .
  • a diameter of the microlens 109 may be approximately equal to a diameter of the optical filter 108 measured in a hori zontal direction . Due to the presence of the microlens 109 , the angle of incidence of electromagnetic radiation on the optical filter 108 is spread. In particular, the angle distribution of incoming light is largely increased. As a consequence, a collection of different angles of incidence will overlap different phases of the ripple. Accordingly, the effect of interference is reduced or even suppressed. As a result, the quality of the optical or color filter 108 is improved .
  • a passivation layer 122 may be optionally arranged over the detection region.
  • the passivation layer 122 may comprise a transparent material such as silicon oxide and may be formed during the manufacture of the detection region.
  • a thickness of the passivation layer may be 5 to 10 pm.
  • the size of the detection region 105 may be reduced with respect to a lateral width of the optical filter 108.
  • Fig. 1 shows a first bundle of rays 120 which are incident in a vertical direction and parallel to an optical axis of the microlens 109. Further, Fig. 1 shows a second bundle of rays 121 which are incident from an oblique direction. Fig. 1 further shows the positions of incidence of the respective bundles of light on the detection region 105.
  • the microlens 109 may be arranged so that the first bundle of rays 120 is focused on the detection region 105. According to further examples, the microlens 109 may be arranged so that the first bundle of rays 120 is not focused on the detection region 105.
  • the detection region 105 may be arranged over a suitable substrate, e.g. a semiconductor or silicon substrate
  • the detection region 105 may comprise generally known photodetector arrangements such as CMOS sensors ("complementary metal-oxide-semiconductor” ) or CCD ("charge coupled device") sensors.
  • the detection region 105 may be manufactured by processing a portion of the substrate, e.g. a silicon substrate.
  • peripheral portions 106 may be arranged at the edge portion of the optical sensor element 10.
  • an insulating material may be arranged in the peripheral portion 106.
  • wirings for electrically contacting e.g. the detection range 105 may be arranged in the peripheral portion 106.
  • Fig. 2A shows a schematic cross-sectional view of a multi- spectral optical sensor 20 according to embodiments.
  • a multi-spectral optical sensor 20 comprises an array of detection regions 105, and an array of optical filters 108. At least one of the optical filters 108 is transparent for electromagnetic radiation in a first wavelength region, at least a further one of the optical filters being transparent for electromagnetic radiation in a second wavelength region different from the first wavelength region. Accordingly, two of the optical filters are transparent for mutually different colors.
  • the term "a first wavelength region different from a second wavelength region" is intended to mean that these regions are not identical, e.g. may have different starting wavelengths and/or different ending wavelengths.
  • the multi-spectral optical sensor 20 further comprises an adhesive layer 107 between the array of detection regions and the array of optical filters.
  • the adhesive layer 107 is adjacent to a first main surface of the optical filters 108.
  • the adhesive layer has a thickness of more than 1 pm and less than 20 pm.
  • the adhesive layer is transparent to the electromagnetic radiation transmitted by the array of optical filters .
  • the adhesive layer may comprise or consist of an epoxy material .
  • the multi-spectral optical sensor 20 further comprises a microlens array 110 over a second main surface 118 of the array of optical filters 108 .
  • a microlens array 110 over a second main surface 118 of the array of optical filters 108 .
  • ripple- like interference may be reduced or even avoided .
  • the optical filter 108 may be arranged on a side of the transparent carrier facing the detection region 105 .
  • the adhesive layer 107 may be directly adj acent to a first main surface 117 of the optical filter .
  • the adhesive layer 107 may be directly adj acent to the transparent carrier 123 carrying the optical filter 108 .
  • the microlens array 110 or the microlens 109 may be directly adj acent to the second main surface 118 of the optical filter 108 .
  • further layers may be arranged between the second main surface 118 and the microlens array 110 or the microlens 109 .
  • the transparent carrier 123 may be arranged between the microlens 109 or the microlens array 110 and the optical filter 108 .
  • the detection region 105 of each sensor element 10 is arranged in a central portion of the sensor element 10 . Further, the detection region 105 may be absent from a peripheral region 106 of each of the sensor elements 10. For example, a size of the detection region 105 may be less than 150 x 150 pm, e.g. less than 120 x 120 pm or even less than 100 x 100 pm. For example, a size of the sensor elements may be larger than 150 pm, e.g. 180 to 220 pm. As is shown in the right-hand portion of Fig. 2A, the detection region 105 may be implemented by a photodetector 111, e.g. a photodiode. Due to the reduced size, a capacitance may be reduced. Further, due to the reduced size, noise may be reduced and the speed may increased, thus increasing the electrical performance of the device.
  • a photodetector 111 e.g. a photodiode. Due to the reduced size, a capacitance may be reduced. Further, due to
  • Wirings 112 electrically connected to the photodetector 111 may be arranged in the peripheral region 106. As a consequence, a size of the multi-spectral optical sensor 20 may be further reduced.
  • Fig. 2B shows a top view of a multi-spectral optical sensor 20 according to embodiments.
  • the multi-spectral optical sensor 20 comprises an array of optical sensor elements 10 which may be e.g. arranged in rows and columns.
  • the optical filters 108 of the multi-spectral optical sensor 20 may have different passbands. For example, some of the optical filters 108 may transmit red light, others may be transparent for green light, and others may be transparent for a third, fourth and fifth wavelength region.
  • the multi-spectral optical sensor 20 described herein above may be used as an ambient light sensor (ALS) .
  • ALS ambient light sensor
  • an ambient light sensor may be a component of an electronic device, such as a mobile phone.
  • Fig. 3 shows a schematic view of an electronic device 40.
  • the electronic device 40 may comprise the multi- spectral optical sensor 20 as described above .
  • the electronic device 40 may further comprise a camera portion 45 .
  • the electronic device may be implemented as a mobile phone , a smart phone , a computer, a laptop or a camera .
  • Fig . 4 shows a schematic cross-sectional view of a multi- spectral optical sensor 20 according to further embodiments .
  • the multi-spectral optical sensor 20 of Fig . 4 comprises similar or identical components as the multi-spectral optical sensor of Fig . 2A.
  • the optical filter 108 is arranged to be adj acent to the detection region 105 .
  • a passivation layer 122 may be arranged over a wafer or an array of detection regions 105 .
  • the passivation layer 122 may comprise silicon oxide .
  • a thickness of the passivation layer 122 may be smaller than 10 pm .
  • the thickness of the passivation layer 122 may be larger than 5 pm .
  • the passivation layer 122 may be part of a CMOS process for manufacturing the detection region 105 .
  • the passivation layer may protect a surface of the detection region 105 from environmental influences .
  • the optical filter 108 may be arranged directly adj acent to the passivation layer 122 or directly adj acent to a surface of the detection region 105 .
  • the microlens 109 or the microlens array 100 may be arranged over a transparent carrier 123 .
  • the transparent carrier 123 may be attached to the optical filter 108 by means of the adhesive 107 .
  • the adhesive 107 may be implemented in a similar manner as has been described above .
  • the detection region 105 may comprise a CMOS de- tection region.
  • the multispectral optical sensor 20 may be employed for electromagnetic radiation in the visible or near infrared range.
  • the multispectral optical sensor 20 may comprise a plurality or an array of optical sensor elements 10.
  • the optical sensor element 10 comprises a detection region 105, an optical filter 108 arranged over the detection region 105 so that a first main surface 117 of the optical filter is adjacent to the detection region.
  • the optical sensor element 10 further comprises a microlens 109 over a second main surface 118 of the optical filter 108, and an adhesive 107 between the optical filter 108 and the microlens 109.
  • Figs. 5A to 5C show top views of the multi-spectral optical sensor 20 according to embodiments.
  • the multi-spectral optical sensor 20 comprises an array of optical sensor elements 10.
  • the optical sensor elements 10 may be implemented in an arbitrary manner, e.g. as explained above with reference to Figs. 1, 2A or 4.
  • the optical sensor elements 10 may be e.g. arranged in rows and columns.
  • the optical filters 108 of the multi-spectral optical sensor 20 may have different passbands. For example, some of the optical filters 108 may transmit red light, others may be transparent for green light, and others may be transparent for a third, fourth and fifth wavelength region .
  • the microlens array 110 may comprise a plurality of microlenses 109 having a circular aperture or shape in a plane parallel to a main surface of the transparent carrier.
  • a size of the aperture is selected so that microlenses 109 of adjacent sensor elements 10 do not contact each other.
  • the apertures of the microlenses 109 are circular .
  • the si ze of the apertures is selected so that microlenses 109 are in contact with microlenses of adj acent sensor elements 10 .
  • a blocking material 124 which may e . g . comprise chromium may be arranged between adj acent mircolenses 109 in order to suppress stray light .
  • the blocking material 124 may be arranged over the transparent carrier 123 .
  • the microlenses 109 may have a rectangular aperture or shape in a plane parallel to a main surface of the transparent carrier 123 . Further, the microlenses may be arranged to be in contact with adj acent ones of the microlenses 109 . According to this configuration, the fill factor may be increased and stray light may be reduced without the presence of a blocking layer 124 . As a result , the light ef ficiency may be further improved .
  • the multi-spectral optical sensor 20 described herein above may be used as an ambient light sensor (ALS ) .
  • an ambient light sensor may be a component of an electronic device , such as a mobile phone .

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electromagnetism (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Solid State Image Pick-Up Elements (AREA)

Abstract

An optical sensor element (10) comprises a detection region (105), an optical filter (108), an adhesive layer (107) between the detection region (105) and a first main surface (117) of the optical filter (108), the adhesive layer (107) having a thickness of more than 1 µm and less than 20 µm, and a microlens (109) over a second main surface (118) of the optical filter (108).

Description

OPTICAL SENSOR ELEMENT , MULTI -SPECTRAL OPTICAL SENSOR AND ELECTRONIC DEVICE
TECHNICAL FIELD
The present disclosure refers to an optical sensor element , a multi-spectral optical sensor and an electronic device .
Spectral reconstruction is an important issue to be managed in multi-spectral photography . For example , ef fects of an ambient light source may be compensated using a multi-spectral ambient light sensor (ALS ) which may be used for measuring the spectral information relating to a scene .
Ef forts are being taken to provide improved multi-spectral optical sensors .
It is an obj ect of the present invention to provide an improved optical sensor element and an improved multi-spectral optical sensor .
According to embodiments , the above obj ect is achieved by the claimed matter according to the independent claims . Further developments are defined in the dependent claims .
SUMMARY
According to embodiments , an optical sensor element comprises a detection region, an optical filter, an adhesive layer between the detection region and a first main surface of the optical filter, the adhesive layer having a thickness of more than 1pm and less than 20 pm, and a microlens over a second main surface of the optical filter . For example , the optical filter is transparent for a visible wavelength range of a certain color .
According to embodiments , a lateral width of the detection region is smaller than a lateral width of the optical filter .
According to further embodiments , a multi-spectral optical sensor comprises an array of detection regions and an array of optical filters . At least one of the optical filters is transparent for electromagnetic radiation in a first wavelength region, at least a further one of the optical filters is transparent for electromagnetic radiation in a second wavelength region di f ferent from the first wavelength region . The multi- spectral optical sensor further comprises an adhesive layer between the array of detection regions and the array of optical filters , the adhesive layer being adj acent to a first main surface of the optical filters , the adhesive layer having a thickness o f more than 1pm and less than 20 pm and a microlens array over a second main surface of the array of optical filters .
For example , the multi-spectral optical sensor may further comprise a peripheral region between adj acent detection regions .
According to embodiments , an insulating material may be arranged in the peripheral region . According to further embodiments , wirings may be arranged in the peripheral region .
According to embodiments , the microlens array may comprise a plurality of microlenses having a rectangular aperture . The microlenses may be arranged to be in contact with adj acent ones of the microlenses . An electronic device comprises the multi-spectral optical sensor as described above . For example , the electronic device may be a mobile phone , a smart phone , a computer, a laptop or a camera .
According to further embodiments , an optical sensor element comprises a detection region, an optical filter arranged over the detection region so that a first main surface of the optical filter is adj acent to the detection region and a microlens directly adj acent to a second main surface of the optical filter .
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this speci fication . The drawings illustrate the embodiments of the present invention and together with the description serve to explain the principles . Other embodiments of the invention and many of the intended advantages will be readily appreciated, as they become better understood by reference to the following detailed description . The elements of the drawings are not necessarily to scale relative to each other . Like reference numbers designate corresponding similar parts .
Fig . 1 shows a schematic view of an optical sensor element according to embodiments .
Fig . 2A shows a schematic cross-sectional view of a multi- spectral optical sensor according to embodiments .
Fig . 2B shows a top view of a multi-spectral optical sensor shown in Fig . 2A. Fig. 3 shows a schematic view of an electronic device according to embodiments.
Fig. 4 shows a schematic view of an optical sensor element according to further embodiments.
Figs. 5A to 5C show top views of a multi-spectral optical sensor according to embodiments.
DETAILED DESCRIPTION
In the following detailed description reference is made to the accompanying drawings, which form a part hereof and in which are illustrated by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "over", "on", "above", "leading", "trailing" etc. is used with reference to the orientation of the Figures being described. Since components of embodiments of the invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims.
The description of the embodiments is not limiting. In particular, elements of the embodiments described hereinafter may be combined with elements of different embodiments.
The terms "lateral" and "horizontal" as used in this specification intends to describe an orientation parallel to a first surface of a substrate or semiconductor body. This can be for instance the surface of a wafer or a die. The term "vertical" as used in this speci fication intends to describe an orientation which is arranged perpendicular to the first surface of a substrate or semiconductor body .
Fig . 1 shows a schematic cross- sectional view of an optical sensor element 10 according to embodiments . The optical sensor element 10 comprises a detection region 105 and an optical filter 108 . An adhesive layer 107 is arranged between the detection region 105 and a first main surface 117 of the optical filter 108 . The adhesive layer 107 has a thickness of more than 1 pm and less than 20 pm . The optical sensor element 10 further comprises a microlens 109 over a second main surface 118 of the optical filter 108 .
For example , the optical filter 108 is transparent for a visible wavelength of a certain color . In more detail , the optical filter 108 may be implemented e . g . by a passband optical interference filter which selectively transmits incoming wavelengths of a certain passband . For example , the interference filter may be implemented by a stack of thin layers arranged . The optical filter 108 may be arranged over a transparent carrier 123 , e . g . a glass carrier . For example , the optical filter 108 may have a thickness of approximately 2 to 5 pm, e . g . approximately 3 pm . The transparent carrier 123 may have a thickness of 100 to 300 pm . As is illustrated in Fig . 2A, the optical filter 108 may be arranged on a side of the transparent carrier 123 remote from the detection region 105 and facing the microlens 109 . The first main surface 117 of the optical filter 108 may be arranged adj acent to the transparent carrier 123 . The adhesive layer 107 may be directly adj acent to transparent carrier 123 . According to further embodiments , the optical filter 108 may be arranged on a side of the transparent carrier 123 facing the dection region 105 . This will be explained with reference to Fig . 2A.
The optical filter 108 including the transparent carrier 123 is attached to the detection region 105 by means of a suitable adhesive layer 107 . The adhesive layer 107 is transparent to the electromagnetic radiation transmitted by the optical filter 108 . For example , the adhesive layer may comprise or consist of an epoxy layer . According to further embodiments , the adhesive may comprise silicones , acrylics , polyimides , depending on the applications intended for the optical sensor .
The adhesive layer has a thickness of more than 1 pm and less than 20 pm . For example , a thickness of the adhesive layer may be 7 to 15 pm or 8 to 12 pm . Due to the small layer thickness of the adhesive layer 107 , ripple-like interference may occur in transmission which impairs the functionality of the color filter . In particular, i f the color filter is configured to transmit longer wavelengths , a typical thickness of the adhesive layer 107 may be in a same range as the wavelength . Accordingly, the impact of the interference gets more severe . Further, the ripple-like interference depends on an angle of incidence of light rays on the color filter .
Due to the presence of the microlens 109 over the second main surface 118 of the optical filter 108 , this interference may be reduced or suppressed . The term "microlens" refers to a lens having a diameter less than 1 mm, e . g . less than 100 pm . For example , a diameter of the microlens 109 may be approximately equal to a diameter of the optical filter 108 measured in a hori zontal direction . Due to the presence of the microlens 109 , the angle of incidence of electromagnetic radiation on the optical filter 108 is spread. In particular, the angle distribution of incoming light is largely increased. As a consequence, a collection of different angles of incidence will overlap different phases of the ripple. Accordingly, the effect of interference is reduced or even suppressed. As a result, the quality of the optical or color filter 108 is improved .
According to all embodiments disclosed herein, a passivation layer 122 may be optionally arranged over the detection region. For example, the passivation layer 122 may comprise a transparent material such as silicon oxide and may be formed during the manufacture of the detection region. A thickness of the passivation layer may be 5 to 10 pm.
Due to the focusing effect of the microlens 109, the size of the detection region 105 may be reduced with respect to a lateral width of the optical filter 108.
Fig. 1 shows a first bundle of rays 120 which are incident in a vertical direction and parallel to an optical axis of the microlens 109. Further, Fig. 1 shows a second bundle of rays 121 which are incident from an oblique direction. Fig. 1 further shows the positions of incidence of the respective bundles of light on the detection region 105. For example, the microlens 109 may be arranged so that the first bundle of rays 120 is focused on the detection region 105. According to further examples, the microlens 109 may be arranged so that the first bundle of rays 120 is not focused on the detection region 105.
For example, the detection region 105 may be arranged over a suitable substrate, e.g. a semiconductor or silicon substrate
100. The detection region 105 may comprise generally known photodetector arrangements such as CMOS sensors ("complementary metal-oxide-semiconductor" ) or CCD ("charge coupled device") sensors. The detection region 105 may be manufactured by processing a portion of the substrate, e.g. a silicon substrate. Further, peripheral portions 106 may be arranged at the edge portion of the optical sensor element 10. For example, an insulating material may be arranged in the peripheral portion 106. Further, as will be shown in Fig. 2A, wirings for electrically contacting e.g. the detection range 105 may be arranged in the peripheral portion 106.
Fig. 2A shows a schematic cross-sectional view of a multi- spectral optical sensor 20 according to embodiments. As will be discussed in the following, a multi-spectral optical sensor 20 comprises an array of detection regions 105, and an array of optical filters 108. At least one of the optical filters 108 is transparent for electromagnetic radiation in a first wavelength region, at least a further one of the optical filters being transparent for electromagnetic radiation in a second wavelength region different from the first wavelength region. Accordingly, two of the optical filters are transparent for mutually different colors. In more detail, the term "a first wavelength region different from a second wavelength region" is intended to mean that these regions are not identical, e.g. may have different starting wavelengths and/or different ending wavelengths. Nevertheless, there may be an overlap between the first wavelength region and the second wavelength region. The multi-spectral optical sensor 20 further comprises an adhesive layer 107 between the array of detection regions and the array of optical filters. The adhesive layer 107 is adjacent to a first main surface of the optical filters 108. The adhesive layer has a thickness of more than 1 pm and less than 20 pm. The adhesive layer is transparent to the electromagnetic radiation transmitted by the array of optical filters . For example , the adhesive layer may comprise or consist of an epoxy material .
The multi-spectral optical sensor 20 further comprises a microlens array 110 over a second main surface 118 of the array of optical filters 108 . In the same manner as has been discussed above with respect to Fig . 1 , due to the presence of the microlens array 110 , ripple- like interference may be reduced or even avoided .
According to embodiments illustrated in Fig . 2A, the optical filter 108 may be arranged on a side of the transparent carrier facing the detection region 105 .
For example , according to all embodiments described herein, the adhesive layer 107 may be directly adj acent to a first main surface 117 of the optical filter . According to further embodiments , the adhesive layer 107 may be directly adj acent to the transparent carrier 123 carrying the optical filter 108 .
Moreover, according to all embodiments described herein, the microlens array 110 or the microlens 109 may be directly adj acent to the second main surface 118 of the optical filter 108 . According to further implementations , further layers may be arranged between the second main surface 118 and the microlens array 110 or the microlens 109 . According to still further implementations , as is illustrated in Fig . 2A, the transparent carrier 123 may be arranged between the microlens 109 or the microlens array 110 and the optical filter 108 .
As is further shown in Fig . 2A, the detection region 105 of each sensor element 10 is arranged in a central portion of the sensor element 10 . Further, the detection region 105 may be absent from a peripheral region 106 of each of the sensor elements 10. For example, a size of the detection region 105 may be less than 150 x 150 pm, e.g. less than 120 x 120 pm or even less than 100 x 100 pm. For example, a size of the sensor elements may be larger than 150 pm, e.g. 180 to 220 pm. As is shown in the right-hand portion of Fig. 2A, the detection region 105 may be implemented by a photodetector 111, e.g. a photodiode. Due to the reduced size, a capacitance may be reduced. Further, due to the reduced size, noise may be reduced and the speed may increased, thus increasing the electrical performance of the device.
Wirings 112 electrically connected to the photodetector 111 may be arranged in the peripheral region 106. As a consequence, a size of the multi-spectral optical sensor 20 may be further reduced.
Fig. 2B shows a top view of a multi-spectral optical sensor 20 according to embodiments. As is shown, the multi-spectral optical sensor 20 comprises an array of optical sensor elements 10 which may be e.g. arranged in rows and columns. The optical filters 108 of the multi-spectral optical sensor 20 may have different passbands. For example, some of the optical filters 108 may transmit red light, others may be transparent for green light, and others may be transparent for a third, fourth and fifth wavelength region.
For example, the multi-spectral optical sensor 20 described herein above may be used as an ambient light sensor (ALS) . In more detail, such an ambient light sensor may be a component of an electronic device, such as a mobile phone.
Fig. 3 shows a schematic view of an electronic device 40. For example, the electronic device 40 may comprise the multi- spectral optical sensor 20 as described above . The electronic device 40 may further comprise a camera portion 45 . For example , the electronic device may be implemented as a mobile phone , a smart phone , a computer, a laptop or a camera .
Fig . 4 shows a schematic cross-sectional view of a multi- spectral optical sensor 20 according to further embodiments . The multi-spectral optical sensor 20 of Fig . 4 comprises similar or identical components as the multi-spectral optical sensor of Fig . 2A. Di f fering from embodiments described with reference to Fig . 2A, according to Fig . 4 , the optical filter 108 is arranged to be adj acent to the detection region 105 . For example , a passivation layer 122 may be arranged over a wafer or an array of detection regions 105 . For example , the passivation layer 122 may comprise silicon oxide . A thickness of the passivation layer 122 may be smaller than 10 pm . The thickness of the passivation layer 122 may be larger than 5 pm . The passivation layer 122 may be part of a CMOS process for manufacturing the detection region 105 . The passivation layer may protect a surface of the detection region 105 from environmental influences . For example , the optical filter 108 may be arranged directly adj acent to the passivation layer 122 or directly adj acent to a surface of the detection region 105 .
The microlens 109 or the microlens array 100 may be arranged over a transparent carrier 123 . The transparent carrier 123 may be attached to the optical filter 108 by means of the adhesive 107 . The adhesive 107 may be implemented in a similar manner as has been described above .
For example , due to the presence of the microlens 109 , interference in the passivation layer 122 or in any other insulating layer within the detection region 105 may be reduced or eliminated . The detection region 105 may comprise a CMOS de- tection region. For example, the multispectral optical sensor 20 may be employed for electromagnetic radiation in the visible or near infrared range.
For example, the multispectral optical sensor 20 may comprise a plurality or an array of optical sensor elements 10. The optical sensor element 10 comprises a detection region 105, an optical filter 108 arranged over the detection region 105 so that a first main surface 117 of the optical filter is adjacent to the detection region. The optical sensor element 10 further comprises a microlens 109 over a second main surface 118 of the optical filter 108, and an adhesive 107 between the optical filter 108 and the microlens 109.
Figs. 5A to 5C show top views of the multi-spectral optical sensor 20 according to embodiments. The multi-spectral optical sensor 20 comprises an array of optical sensor elements 10. The optical sensor elements 10 may be implemented in an arbitrary manner, e.g. as explained above with reference to Figs. 1, 2A or 4. The optical sensor elements 10 may be e.g. arranged in rows and columns. The optical filters 108 of the multi-spectral optical sensor 20 may have different passbands. For example, some of the optical filters 108 may transmit red light, others may be transparent for green light, and others may be transparent for a third, fourth and fifth wavelength region .
As is specifically illustrated in Fig. 5A, the microlens array 110 may comprise a plurality of microlenses 109 having a circular aperture or shape in a plane parallel to a main surface of the transparent carrier. As is further illustrated in Fig. 5A, a size of the aperture is selected so that microlenses 109 of adjacent sensor elements 10 do not contact each other. According to the implementation of Fig . 5B, the apertures of the microlenses 109 are circular . Further, the si ze of the apertures is selected so that microlenses 109 are in contact with microlenses of adj acent sensor elements 10 .
According to embodiments illustrated in Figs . 5A and 5B, a blocking material 124 which may e . g . comprise chromium may be arranged between adj acent mircolenses 109 in order to suppress stray light . For example , the blocking material 124 may be arranged over the transparent carrier 123 .
According to embodiments illustrated in Fig . 5C, the microlenses 109 may have a rectangular aperture or shape in a plane parallel to a main surface of the transparent carrier 123 . Further, the microlenses may be arranged to be in contact with adj acent ones of the microlenses 109 . According to this configuration, the fill factor may be increased and stray light may be reduced without the presence of a blocking layer 124 . As a result , the light ef ficiency may be further improved .
For example , the multi-spectral optical sensor 20 described herein above may be used as an ambient light sensor (ALS ) . In more detail , such an ambient light sensor may be a component of an electronic device , such as a mobile phone .
While embodiments of the invention have been described above , it is obvious that further embodiments may be implemented . For example , further embodiments may comprise any subcombination of features recited in the claims or any subcombination of elements described in the examples given above . Accordingly, this spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein + A + LIST OF REFERENCES optical sensor element multi-spectral optical sensor electronic device camera portion substrate detection region peripheral region adhesive layer optical filter microlens microlens array photodetector element wiring first main surface of optical filter second main surface of optical filter first bundle of rays second bundle of rays passivation layer transparent carrier blocking layer

Claims

1. An optical sensor element (10) comprising: a detection region (105) ; an optical filter (108) , an adhesive layer (107) between the detection region (105) and a first main surface (117) of the optical filter (108) , the adhesive layer (107) having a thickness of more than 1pm and less than 20 pm; and a microlens (109) over a second main surface (118) of the optical filter (108) , characterized in that the optical sensor element (10) further comprises a peripheral region (106) arranged at the edge portion of the optical sensor element (10) , wherein wirings (112) are arranged in the peripheral region (106) .
2. The optical sensor element (10) according to claim 1, wherein the optical filter (108) is transparent for a visible wavelength range of a certain color.
3. The optical sensor element (10) according to claim 1 or 2, wherein a lateral width of the detection region (105) is smaller than a lateral width of the optical filter (108) .
4. A multi-spectral optical sensor (20) comprising: an array of detection regions (105) ; an array of optical filters (108) , at least one of the optical filters (108) being transparent for electromagnetic radiation in a first wavelength region, at least a further one of the optical filters (108) being transparent for electromagnetic radiation in a second wavelength region different from the first wavelength region; an adhesive layer (107) between the array of detection regions (105) and the array of optical filters (108) , the adhesive layer (107) being adjacent to a first main surface (117) of the optical filters (108) , the adhesive layer (107) having a thickness of more than 1pm and less than 20 pm; and a microlens array (110) over a second main surface (118) of the array of optical filters (108) , characterized in that the multi-spectral optical sensor (20) further comprises a peripheral region (106) between adjacent detection regions (105) , wherein wirings (112) are arranged in the peripheral region (106) .
5. The multi-spectral optical sensor (20) according to claim 4, wherein an insulating material is arranged in the peripheral region (106) .
6. The multi-spectral optical sensor according claim 4 or 5, wherein the micorlens array (110) comprises a plurality of microlenses having a rectangular aperture, wherein the microlenses are arranged to be in contact with adjacent ones of the microlenses .
7. An electronic device (40) comprising the multi-spectral optical sensor (20) according to any of claims 4 to 6.
8. The electronic device (40) according to claim 7, being selected from a mobile phone, a smart phone, a computer, a laptop and a camera.
9. An optical sensor element (10) comprising: a detection region (105) ; an optical filter (108) arranged over the detection region (105) so that a first main surface (117) of the optical filter is adjacent to the detection region; a microlens (109) over a second main surface (118) of the optical filter (108) ; and an adhesive (107) between the optical filter (108) and the microlens (109) , characterized in that the optical sensor element (10) further comprises a peripheral region (106) arranged at the edge portion of the optical sensor element (10) , wherein wirings (112) are arranged in the peripheral region (106) .
PCT/EP2023/080850 2022-12-02 2023-11-06 Optical sensor element, multi-spectral optical sensor and electronic device WO2024115046A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102022132059.6 2022-12-02
DE102022132059 2022-12-02

Publications (1)

Publication Number Publication Date
WO2024115046A1 true WO2024115046A1 (en) 2024-06-06

Family

ID=88731712

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/EP2023/080850 WO2024115046A1 (en) 2022-12-02 2023-11-06 Optical sensor element, multi-spectral optical sensor and electronic device

Country Status (1)

Country Link
WO (1) WO2024115046A1 (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050274968A1 (en) * 2004-06-10 2005-12-15 Kuo Ching-Sen Lens structures suitable for use in image sensors and method for making the same
US20070158532A1 (en) * 2006-01-12 2007-07-12 Taiwan Semiconductor Manufacturing Company, Ltd. True color image by modified microlens array
US20090090850A1 (en) * 2006-08-31 2009-04-09 Aptina Imaging Corporation Deep Recess Color Filter Array and Process of Forming the Same
JP5574419B2 (en) * 2010-06-17 2014-08-20 パナソニック株式会社 Solid-state imaging device and manufacturing method thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20050274968A1 (en) * 2004-06-10 2005-12-15 Kuo Ching-Sen Lens structures suitable for use in image sensors and method for making the same
US20070158532A1 (en) * 2006-01-12 2007-07-12 Taiwan Semiconductor Manufacturing Company, Ltd. True color image by modified microlens array
US20090090850A1 (en) * 2006-08-31 2009-04-09 Aptina Imaging Corporation Deep Recess Color Filter Array and Process of Forming the Same
JP5574419B2 (en) * 2010-06-17 2014-08-20 パナソニック株式会社 Solid-state imaging device and manufacturing method thereof

Similar Documents

Publication Publication Date Title
US9348019B2 (en) Hybrid image-sensing apparatus having filters permitting incident light in infrared region to be passed to time-of-flight pixel
US9880391B2 (en) Lens array modules and wafer-level techniques for fabricating the same
US20100044815A1 (en) Cmos image sensor package and camera module using same
US10840293B2 (en) Image sensor structure
KR102382364B1 (en) Wafer level image sensor package
US11323608B2 (en) Image sensors with phase detection auto-focus pixels
US20130038764A1 (en) Image pickup apparatus and camera module
US10880467B2 (en) Image sensors with phase detection auto-focus pixels
US10451483B2 (en) Short wave infrared polarimeter
WO2024115046A1 (en) Optical sensor element, multi-spectral optical sensor and electronic device
US20220344384A1 (en) Image sensor
US11817468B2 (en) Image sensing device
TWI784299B (en) Image sensor structure
CN211480030U (en) Thin optical fingerprint identification device
CN113542638B (en) Image sensing device
US20240079421A1 (en) Image sensor
US20220165766A1 (en) Image sensor and manufacturing process thereof
US11676982B2 (en) Image sensing device
WO2024024335A1 (en) Light detection device
US20240120357A1 (en) Image sensor
JP2012151421A (en) Image sensing device
US20220199673A1 (en) Multispectral image sensor and method for fabrication of an image sensor
CN116741788A (en) Solid-state imaging device, electronic apparatus, and method for manufacturing solid-state imaging device
US20100044553A1 (en) Cmos image sensor package and camera module with same
CN114628421A (en) Image sensor with varying grid width