US20190074314A1 - Image sensor packages - Google Patents
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- US20190074314A1 US20190074314A1 US15/697,825 US201715697825A US2019074314A1 US 20190074314 A1 US20190074314 A1 US 20190074314A1 US 201715697825 A US201715697825 A US 201715697825A US 2019074314 A1 US2019074314 A1 US 2019074314A1
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Images
Classifications
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- 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
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- 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
-
- 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
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- 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
- H01L27/14643—Photodiode arrays; MOS imagers
- H01L27/14649—Infrared imagers
-
- 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
- H01L31/0232—Optical elements or arrangements associated with the device
- H01L31/02327—Optical elements or arrangements associated with the device the optical elements being integrated or being directly associated to the device, e.g. back reflectors
Definitions
- This invention relates to image sensor technology, and more particularly to image sensor packages with an optical filter and a metal-insulator-metal structure.
- an image sensor To capture a color image of a scene, an image sensor must be sensitive to a broad spectrum of light. The image sensor reacts to light that is reflected from the scene and can convert the strength of that light into electronic signals.
- An image sensor such as a charge-coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor, generally has photoelectric conversion regions that convert incident light into electronic signals.
- the image sensor has logic circuits for transmitting and processing the electronic signals.
- image sensors are widely applied in many fields, as well as in devices such as light sensors, proximity sensors, time-of-flight (TOF) cameras, spectrometers, smart sensors used in the Internet of things (TOT), and sensors for advanced driver assistance systems (ADAS), for example.
- TOF time-of-flight
- ADAS advanced driver assistance systems
- image sensor packages have an optical filter and a metal-insulator-metal structure disposed above photoelectric conversion regions.
- the optical filter can absorb the light that is not expected to be transmitted to the photoelectric conversion regions of the image sensor packages, increasing the signal-to-noise (S/N) ratio.
- the metal-insulator-metal (MIM) structure can narrow the full width at half maximum (FWHM) of the light transmitted to the photoelectric conversion regions.
- the image sensor package can produce a high signal-to-noise (S/N) ratio.
- the MIM structure can help the image sensor package to reduce the blue shift, and decrease the decay of the angular response at large angles of incidence.
- the MIM structure is thin enough to reduce the overall size of the image sensor package.
- an image sensor package in some embodiments, includes a medium layer having a first surface and a second surface opposite to the first surface.
- the image sensor package also includes a metal-insulator-metal structure disposed on the first surface of the medium layer, wherein the metal-insulator-metal structure includes a first metal layer, a first insulating layer, and a second metal layer, and wherein the first insulating layer is disposed between the first metal layer and the second metal layer.
- the image sensor package further includes an optical filter disposed on the second surface of the medium layer.
- FIG. 1A shows a partial cross section of an image sensor package according to some embodiments
- FIG. 1B shows a partial cross section of an image sensor package according to some embodiments
- FIG. 1C shows a partial cross section of an image sensor package according to some embodiments
- FIG. 1D shows a partial cross section of an image sensor package according to some embodiments
- FIG. 1E shows a partial cross section of an image sensor package according to some embodiments
- FIG. 1F shows a partial cross section of an image sensor package according to some embodiments
- FIG. 2 shows a cross section of an image sensor module that includes an image sensor package of FIGS. 1A to 1F according to some embodiments;
- FIG. 3 is a diagram illustrating transmission characteristics of various optical filters with different thicknesses according to some embodiments.
- FIG. 4A is a diagram illustrating normalized angular response characteristics of a MIM structure according to some embodiments.
- FIGS. 4B and 4C are simulated electric fields of a MIM structure in the X-Z plane of FIGS. 1A to 1F according to some embodiments.
- FIG. 4B shows the electric field distribution of the MIM structure when the angle of incidence is 0 degrees.
- FIG. 4C shows the electric field distribution of the MIM structure when the angle of incidence is 30 degrees;
- FIG. 5 is a diagram illustrating the transmission characteristics of a MIM structure according to some embodiments.
- FIGS. 6A and 6B are simulated electric fields of an image sensor package in the X-Z plane of FIGS. 1A to 1F according to some embodiments.
- FIG. 6A shows the electric field distribution of the image sensor package when the wavelength of the incident light is 670 nm.
- FIG. 6B shows the electric field distribution of the image sensor package when the wavelength of the incident light is 940 nm;
- FIG. 7 is a diagram illustrating transmission characteristics of an image sensor package according to some embodiments.
- the image sensor package 100 a is a complementary metal-oxide semiconductor (CMOS) image sensor (CIS) package.
- the image sensor package 100 a includes a semiconductor substrate 101 , for example a silicon wafer or a chip.
- the semiconductor substrate 101 has a plurality of photoelectric conversion regions 103 , and each of the photoelectric conversion regions 103 may include a photoelectric conversion element, such as a photodiode.
- FIG. 1A shows only one photoelectric conversion region 103 , actually the image sensor package 100 a can have multiple photoelectric conversion regions 103 arranged in an array.
- the back surface 101 B of the semiconductor substrate 101 usually has photoelectric conversion regions 103 formed thereon.
- the front surface 101 F of the semiconductor substrate 101 usually has a wiring layer (not shown) of various wiring lines and electronic circuits required for the image sensor package 100 a formed thereon.
- the image sensor package 100 a is a backside illumination (BSI) image sensor package.
- BSI backside illumination
- the back surface 101 B of the semiconductor substrate 101 having the photoelectric conversion regions 103 formed thereon is close to the light receiving surface of the image sensor package 100 a .
- the front surface 101 F of the semiconductor substrate 101 having the wiring layer formed thereon is far from the light receiving surface of the image sensor package 100 a.
- the semiconductor substrate 101 of the image sensor package 100 a is inverted to be a front-side illumination (FSI) image sensor package.
- FSI front-side illumination
- the front surface 101 F of the semiconductor substrate 101 having the wiring layer formed thereon is close to the light receiving surface of the image sensor package 100 a .
- the back surface 101 B of the semiconductor substrate 101 having the photoelectric conversion regions 103 formed thereon is far from the light receiving surface of the image sensor package 100 a .
- the image sensor package 100 a is a BSI image sensor package.
- the image sensor package 100 a further includes a high dielectric-constant (high-k) film 105 formed on the semiconductor substrate 101 and covering the photoelectric conversion region 103 .
- the high-k film 105 can be made of hafnium oxide (HfO 2 ), hafnium tantalum oxide (HfTaO), hafnium titanium oxide (HfTiO), hafnium zirconium oxide (HfZrO), tantalum pentoxide (Ta 2 O 5 ) or another suitable high-k dielectric material and may be formed by a deposition process.
- the high-k film 105 has a high-refractive index, for example, from 2.0 to 2.5, and a light-absorbing ability.
- the image sensor package 100 a includes a metal-insulating-metal (MIM) structure 115 formed on the high-k film 105 .
- the MIM structure 115 includes a first metal layer 107 , a first insulating layer 109 , and a second metal layer 111 .
- the first insulating layer 109 is sandwiched between the first metal layer 107 and the second metal layer 111 .
- FIG. 1A shows three layers in the MIM structure 115 , there can be more than three layers in the MIM structure 115 .
- the MIM structure 115 may be a five-layered structure, which further includes a second insulating layer (not shown) and a third insulating layer (not shown), and the first metal layer 107 , the first insulating layer 109 , and the second metal layer 111 are sandwiched between the second insulating layer and the third insulating layer.
- the metal layers and the insulating layer are arranged alternately.
- the first metal layer 107 and the second metal layer 111 may be made of silver (Ag), and the first insulating layer 109 , the second insulating layer (not shown) and the third insulating layer (not shown) are made of amorphous silicon.
- the first metal layer 107 has a thickness T 1
- the first insulating layer 109 has a thickness T 2
- the second metal layer 111 has a thickness T 3 . Both the thickness T 1 and the thickness T 3 are less than the thickness T 2 .
- the sum of the thicknesses T 1 , T 2 and T 3 is defined as the total thickness T 4 of the MIM structure 115 .
- a five-layered MIM structure is provided.
- the five-layered MIM structure further includes the second and third insulating layers, the first metal layer 107 and the second metal layer 111 are made of silver, and the first insulating layer 109 , the second insulating layer, and the third insulating layer are made of amorphous silicon.
- the thickness T 1 is 20 nm
- the thickness T 2 is 352.8 nm
- the thickness T 3 is 24 nm
- the second and third insulating layers have thicknesses of 77 nm and 96.8 nm, respectively.
- the total thickness of the five-layered MIM structure is about 571 nm, which is very thin.
- a spacer layer (or dam) 117 is disposed on the MIM structure 115 , and a cavity 119 is surrounded by the spacer layer 117 . Moreover, at least a portion of the photoelectric conversion region 103 is not covered by the spacer layer 117 , and the cavity 119 is disposed directly above the portion of the photoelectric conversion region 103 .
- a cover plate 121 is disposed on the spacer layer 117 and the cavity 119 , and the cover plate 121 can be a transparent material. Specifically, the cover plate 121 may be made of glass, a transparent plastic material, or another suitable material. To sum up, the cavity 119 is enclosed by the MIM structure 115 , the spacer layer 117 and the cover plate 121 . The spacer layer 117 , the cavity 119 and the cover plate 121 compose a medium layer 130 a.
- the spacer layer 117 may be made of inorganic materials, for example, silicon oxide, silicon nitride, silicon oxynitride, metal oxide or a combination thereof, organic polymer materials, for example, epoxy resin, polyimide, butylcyclobutene (BCB), parylene, polynaphthalenes, fluorocarbons or acrylates, a photoresist material or another suitable insulating material.
- the cover plate 121 may be any suitable material, including, but not limited to, glass, plastic, acrylic, sapphire, and a combination thereof.
- the cover plate 121 has a thickness T 5 , which is in a range from about 200 ⁇ m to about 500 ⁇ m.
- the refractive index of the cover plate 121 is about 1.55.
- the image sensor package 100 a further includes an optical filter 125 disposed on the cover plate 121 .
- the optical filter 125 may be a blue-light-transmissive filter, a green-light-transmissive filter, a red-light-transmissive filter, or an infrared-transmissive filter.
- the optical filter 125 is made of a photoresist material and a pigment mixed in the photoresist material, and the photoresist material may be an organic material.
- the optical filter 125 has a thickness T 6 which is in a range from about 1 ⁇ m to 20 ⁇ m, especially in a range from about 10 ⁇ m to about 20 ⁇ m.
- the thickness T 5 of the cover plate 121 is greater than the thickness T 6 of the optical filter 125 , and the thickness T 6 of the optical filter 125 is greater than the total thickness T 4 of the MIM structure 115 .
- the image sensor package 100 a in FIG. 1A includes the optical filter 125 and the MIM structure 115 disposed above the photoelectric conversion region 103 , and the optical filter 125 and the MIM structure 115 are disposed on two opposite sides of the medium layer 130 a . Specifically, the MIM structure 115 is disposed between the photo electric conversion region 103 and the medium layer 130 a.
- the optical filter 125 can absorb the light that is not expected to be transmitted to the photoelectric conversion region 103 , thereby the signal-to-noise (S/N) ratio can be increased. In other words, the transmission rate (also called transmittance) of the undesired light can be decreased by the optical filter 125 .
- the MIM structure 115 can narrow the full width at half maximum (FWHM) of the light transmitted to the photoelectric conversion region 103 .
- the image sensor package 100 a can produce a high signal-to-noise (S/N) ratio.
- the MIM structure 115 can help the image sensor package 100 a to reduce the blue shift, and decrease the decay of the angular response at large angles of incidence.
- the size of the image sensor package 100 a will not be increased too much since the MIM structure 115 is thin enough.
- FIG. 1B a partial cross section of an image sensor package 100 b according to some embodiments is shown.
- the spacer layer 117 and the cavity 119 of FIG. 1A are replaced by an adhesive layer 127 , such as a transparent glue, and the adhesive layer 127 and the cover plate 121 compose a medium layer 130 b .
- the positions of the MIM structure 115 and the optical filter 125 in the embodiment of FIG. 1B are not changed from the embodiment of FIG. 1A .
- the MIM structure 115 is attached to the cover plate 121 by the adhesive layer 127 .
- Some components of the image sensor package 100 b are similar to those of the image sensor package 100 a shown in FIG. 1A and are not repeated herein for simplicity.
- FIG. 1C a partial cross section of an image sensor package 100 c according to some embodiments is shown.
- the cover plate 121 and the adhesive layer 127 of FIG. 1B are replaced by a medium layer 123 which is made of a transparent material, and the transparent material has a refractive index in a range from about 1.2 to about 1.6.
- the positions of the MIM structure 115 and the optical filter 125 in the embodiment of FIG. 1C are not changed from the embodiment of FIG. 1B .
- the medium layer 123 has a thickness T 7 which is in a range from about 100 ⁇ m to about 400 ⁇ m.
- the thickness T 7 of the medium layer 123 is greater than the thickness T 6 of the optical filter 125 , and the thickness T 6 of the optical filter 125 is greater than the total thickness T 4 of the MIM structure 115 .
- Some components of the image sensor package 100 c are similar to those of the image sensor package 100 b shown in FIG. 1B and are not repeated herein for simplicity.
- FIG. 1D a partial cross section of an image sensor package 100 d according to some embodiments is shown.
- the positions of the MIM structure 115 and the optical filter 125 are exchanged in the image sensor package 100 d of FIG. 1D .
- the optical filter 125 is sandwiched between the high-k film 105 on the photoelectric conversion region 103 and the adhesive layer 127 under the cover plate 121 .
- the MIM structure 115 is disposed on the cover plate 121 of the medium layer 130 b .
- Some components of the image sensor package 100 d are similar to those of the image sensor package 100 b shown in FIG. 1B and are not repeated herein for simplicity.
- FIG. 1E a partial cross section of an image sensor package 100 e according to some embodiments is shown.
- the positions of the MIM structure 115 and the optical filter 125 are exchanged in the image sensor package 100 e of FIG. 1E .
- the optical filter 125 is sandwiched between the high-k film 105 on the photoelectric conversion region 103 and the medium layer 123 .
- the MIM structure 115 is disposed on the medium layer 123 .
- FIG. 1F a partial cross section of an image sensor package 100 f according to some embodiments is shown.
- the medium layer 130 b of the image sensor package 100 f is disposed on the optical filter 125 , and the MIM structure 115 is sandwiched between the high-k film 105 on the photoelectric conversion region 103 and the optical filter 125 .
- the cover plate 121 of the medium layer 130 b is attached on the optical filter 125 by the adhesive layer 127 .
- Some components of the image sensor package 100 f are similar to those of the image sensor package 100 b shown in FIG. 1B and are not repeated herein for simplicity.
- an image sensor package 100 which may be one of the image sensor packages 100 a , 100 b , 100 c , 100 d , 100 e , 100 f , is mounted on a circuit board 150 by a plurality of conducting structures 160 , such as solder balls, bumps or conductive pillars.
- the image sensor package 100 is electrically connected to the circuit board 150 through the conducting structures 160 .
- the image sensor module 200 further includes a holder 170 , a filter 180 and a lens 190 .
- the holder 170 has a capacity, so that the filter 180 and the lens 190 are disposed within the capacity of the holder 170 and are fixed to the holder 170 . Therefore, the image sensor module 200 is a fixed-focus device.
- the capacity of the holder 170 can further accommodate the image sensor package 100 on the circuit board 150 .
- the filter 180 in the capacity is located between the lens 190 and the image sensor package 100 , and there is a gap between the filter 180 and the image sensor package 100 .
- the filter 180 is made of a light-transmissive material (such as glass) and a filter layer formed on the light-transmissive material.
- the filter 180 may be the cover plate of FIG. 1A
- the holder 170 may be the spacer layer 117 of FIG. 1A .
- the filter 180 is used to eliminate the image noise.
- the lens 190 can be formed by a single lens set or multiple lens sets. To simplify the diagram, only flat filter 180 and lens 190 are depicted herein.
- the structure of the image sensor module 200 is determined by design requirements and is not limited thereto.
- the image sensor module 200 can be a variable focus device.
- the optical filter 125 can decrease the transmission rate of the light that is not expected to be transmitted to the photoelectric conversion region 103 of the image sensor package 100 .
- the visible light which covers the range of wavelengths from about 380 nm to about 750 nm, is expected to be filtered out before reaching the photoelectric conversion region 103 of the IR image sensor package. That is, the visible light cannot be transmitted to the photoelectric conversion region 103 of the IR image sensor package, and the transmission rate of the visible light should be close to 0.
- an IR image sensor package is used to exemplify the properties of the image sensor package 100 mentioned previously.
- an infrared-transmissive filter is used as the optical filter 125 .
- the optical filters 125 i.e. the infrared-transmissive filter with thicknesses of 20 ⁇ m and 7 ⁇ m can completely filter out the visible light of the incident light, while there are still a little bit of visible light passing though the optical filter 125 with a thickness of 1 ⁇ m.
- FIG. 4A a diagram illustrating normalized angular response characteristics of the MIM structure 115 according to some embodiments is shown.
- the MIM structure 115 can decrease the decay of the angular response at large angles of incidence.
- the value of the normalized angular response remains at 1 when the angle of incidence is in a range from 0 degree to about 15 degrees and the value of the normalized angular response slightly drops to about 0.95 when the angles of the incidence increase to 30 degrees.
- FIGS. 4B and 4C simulated electric fields of the MIM structure 115 in the X-Z plane of FIGS. 1A to 1F according to some embodiments are shown.
- FIG. 4B shows the electric field distribution of the MIM structure 115 when the angle of incidence is 0 degree
- FIG. 4C shows the electric field distribution of the MIM structure 115 when the angle of incidence is 30 degrees.
- the width of the photoelectric conversion region 103 is about 1 ⁇ m, which corresponds to the scale of the X-axis in FIGS. 4B and 4C .
- the bar shown on the right hand side represents the electric field intensity, and the electric field intensity is measured in units of volts squared per meter squared (V/m) 2 .
- the electric field intensity of FIG. 4C is only slightly decreased when the angle of incidence comes to 30 degrees.
- the MIM structure 115 can narrow the full width at half maximum (FWHM) of the light transmitted to the photoelectric conversion region 103 and reduce the blue shift. As shown in FIG. 5 , the band widths of the transmission rates of the incident light are narrow, and the MIM structure 115 exhibits a very small blue shift, which is only 7 nm.
- FIGS. 6A and 6B simulated electric fields of an image sensor package 100 in the X-Z plane of FIGS. 1A to 1F according to some embodiments are shown.
- FIG. 6A shows the electric field distribution of the image sensor package 100 when the wavelength of the incident light is 670 nm
- FIG. 6B shows the electric field distribution of the image sensor package 100 when the wavelength of the incident light is 940 nm.
- the width of the photoelectric conversion region 103 is about 1 ⁇ m, which corresponds to the scale of the X-axis in FIGS. 6A and 6B .
- the bar shown on the right hand side represents the electric field intensity, and the electric field intensity is measured in units of volts squared per meter squared (V/m) 2 .
- the incident light with short wavelengths such as 670 nm
- FIG. 7 a diagram illustrating transmission characteristics of an image sensor package 100 according to some embodiments is shown.
- the transmission rate of the undesired light can be decreased (i.e. signal-to-noise (S/N) ratio can be increased), the full width at half maximum (FWHM) of the light expected to be transmitted to the photoelectric conversion region 103 can be decreased (i.e. the band width of the transmitted light can be narrower).
- the image sensor package 100 can produce a high signal-to-noise (S/N) ratio, which can be proved by FIG. 7 .
- the influence of blue shift can be reduced or prevented.
- the image sensor package 100 exhibits a very small blue shift, which is only 7 nm.
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- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
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- Light Receiving Elements (AREA)
Abstract
An image sensor package includes a medium layer having a first surface and a second surface opposite to the first surface. The image sensor package also includes a metal-insulator-metal structure disposed on the first surface of the medium layer. The metal-insulator-metal structure includes a first metal layer, a first insulating layer, and a second metal layer, and the first insulating layer is disposed between the first metal layer and the second metal layer. The image sensor package further includes an optical filter disposed on the second surface of the medium layer.
Description
- This invention relates to image sensor technology, and more particularly to image sensor packages with an optical filter and a metal-insulator-metal structure.
- To capture a color image of a scene, an image sensor must be sensitive to a broad spectrum of light. The image sensor reacts to light that is reflected from the scene and can convert the strength of that light into electronic signals. An image sensor, such as a charge-coupled device (CCD) image sensor or a complementary metal-oxide semiconductor (CMOS) image sensor, generally has photoelectric conversion regions that convert incident light into electronic signals. In addition, the image sensor has logic circuits for transmitting and processing the electronic signals.
- Nowadays, image sensors are widely applied in many fields, as well as in devices such as light sensors, proximity sensors, time-of-flight (TOF) cameras, spectrometers, smart sensors used in the Internet of things (TOT), and sensors for advanced driver assistance systems (ADAS), for example.
- Although existing image sensor packages have been adequate for their intended purposes, they have not been entirely satisfactory in all respects. Therefore, there are still some problems with image sensor packages that remain to be overcome.
- According to embodiments of the disclosure, image sensor packages have an optical filter and a metal-insulator-metal structure disposed above photoelectric conversion regions. The optical filter can absorb the light that is not expected to be transmitted to the photoelectric conversion regions of the image sensor packages, increasing the signal-to-noise (S/N) ratio. In addition, the metal-insulator-metal (MIM) structure can narrow the full width at half maximum (FWHM) of the light transmitted to the photoelectric conversion regions. As a result, the image sensor package can produce a high signal-to-noise (S/N) ratio. Moreover, the MIM structure can help the image sensor package to reduce the blue shift, and decrease the decay of the angular response at large angles of incidence. Furthermore, the MIM structure is thin enough to reduce the overall size of the image sensor package.
- In some embodiments, an image sensor package is provided. The image sensor package includes a medium layer having a first surface and a second surface opposite to the first surface. The image sensor package also includes a metal-insulator-metal structure disposed on the first surface of the medium layer, wherein the metal-insulator-metal structure includes a first metal layer, a first insulating layer, and a second metal layer, and wherein the first insulating layer is disposed between the first metal layer and the second metal layer. The image sensor package further includes an optical filter disposed on the second surface of the medium layer.
- A detailed description is given in the following embodiments with reference to the accompanying drawings.
- The disclosure can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
-
FIG. 1A shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 1B shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 1C shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 1D shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 1E shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 1F shows a partial cross section of an image sensor package according to some embodiments; -
FIG. 2 shows a cross section of an image sensor module that includes an image sensor package ofFIGS. 1A to 1F according to some embodiments; -
FIG. 3 is a diagram illustrating transmission characteristics of various optical filters with different thicknesses according to some embodiments; -
FIG. 4A is a diagram illustrating normalized angular response characteristics of a MIM structure according to some embodiments; -
FIGS. 4B and 4C are simulated electric fields of a MIM structure in the X-Z plane ofFIGS. 1A to 1F according to some embodiments.FIG. 4B shows the electric field distribution of the MIM structure when the angle of incidence is 0 degrees.FIG. 4C shows the electric field distribution of the MIM structure when the angle of incidence is 30 degrees; -
FIG. 5 is a diagram illustrating the transmission characteristics of a MIM structure according to some embodiments; -
FIGS. 6A and 6B are simulated electric fields of an image sensor package in the X-Z plane ofFIGS. 1A to 1F according to some embodiments.FIG. 6A shows the electric field distribution of the image sensor package when the wavelength of the incident light is 670 nm.FIG. 6B shows the electric field distribution of the image sensor package when the wavelength of the incident light is 940 nm; and -
FIG. 7 is a diagram illustrating transmission characteristics of an image sensor package according to some embodiments. - The following description is of the contemplated mode of carrying out the disclosure. This description is made for the purpose of illustrating the general principles of the disclosure and should not be taken in a limiting sense. The scope of the disclosure is best determined by reference to the appended claims.
- Referring to
FIG. 1A , a partial cross section of animage sensor package 100 a according to some embodiments is shown. In some embodiments, theimage sensor package 100 a is a complementary metal-oxide semiconductor (CMOS) image sensor (CIS) package. Theimage sensor package 100 a includes asemiconductor substrate 101, for example a silicon wafer or a chip. Thesemiconductor substrate 101 has a plurality ofphotoelectric conversion regions 103, and each of thephotoelectric conversion regions 103 may include a photoelectric conversion element, such as a photodiode. AlthoughFIG. 1A shows only onephotoelectric conversion region 103, actually theimage sensor package 100 a can have multiplephotoelectric conversion regions 103 arranged in an array. - The
back surface 101B of thesemiconductor substrate 101 usually hasphotoelectric conversion regions 103 formed thereon. The front surface 101F of thesemiconductor substrate 101 usually has a wiring layer (not shown) of various wiring lines and electronic circuits required for theimage sensor package 100 a formed thereon. In some embodiments, theimage sensor package 100 a is a backside illumination (BSI) image sensor package. In the BSI image sensor package, theback surface 101B of thesemiconductor substrate 101 having thephotoelectric conversion regions 103 formed thereon is close to the light receiving surface of theimage sensor package 100 a. The front surface 101F of thesemiconductor substrate 101 having the wiring layer formed thereon is far from the light receiving surface of theimage sensor package 100 a. - In some other embodiments, the
semiconductor substrate 101 of theimage sensor package 100 a is inverted to be a front-side illumination (FSI) image sensor package. In the FSI image sensor package, the front surface 101F of thesemiconductor substrate 101 having the wiring layer formed thereon is close to the light receiving surface of theimage sensor package 100 a. Theback surface 101B of thesemiconductor substrate 101 having thephotoelectric conversion regions 103 formed thereon is far from the light receiving surface of theimage sensor package 100 a. In the present embodiment as shown inFIG. 1A , theimage sensor package 100 a is a BSI image sensor package. - As shown in
FIG. 1A , in accordance with some embodiments, theimage sensor package 100 a further includes a high dielectric-constant (high-k)film 105 formed on thesemiconductor substrate 101 and covering thephotoelectric conversion region 103. The high-k film 105 can be made of hafnium oxide (HfO2), hafnium tantalum oxide (HfTaO), hafnium titanium oxide (HfTiO), hafnium zirconium oxide (HfZrO), tantalum pentoxide (Ta2O5) or another suitable high-k dielectric material and may be formed by a deposition process. The high-k film 105 has a high-refractive index, for example, from 2.0 to 2.5, and a light-absorbing ability. - In some embodiments, the
image sensor package 100 a includes a metal-insulating-metal (MIM)structure 115 formed on the high-k film 105. TheMIM structure 115 includes afirst metal layer 107, a first insulatinglayer 109, and asecond metal layer 111. The first insulatinglayer 109 is sandwiched between thefirst metal layer 107 and thesecond metal layer 111. AlthoughFIG. 1A shows three layers in theMIM structure 115, there can be more than three layers in theMIM structure 115. For example, theMIM structure 115 may be a five-layered structure, which further includes a second insulating layer (not shown) and a third insulating layer (not shown), and thefirst metal layer 107, the first insulatinglayer 109, and thesecond metal layer 111 are sandwiched between the second insulating layer and the third insulating layer. In the MIM structure, the metal layers and the insulating layer are arranged alternately. - In some embodiments, the
first metal layer 107 and thesecond metal layer 111 may be made of silver (Ag), and the first insulatinglayer 109, the second insulating layer (not shown) and the third insulating layer (not shown) are made of amorphous silicon. Thefirst metal layer 107 has a thickness T1, the first insulatinglayer 109 has a thickness T2, and thesecond metal layer 111 has a thickness T3. Both the thickness T1 and the thickness T3 are less than the thickness T2. As shown inFIG. 1A , the sum of the thicknesses T1, T2 and T3 is defined as the total thickness T4 of theMIM structure 115. - In another embodiment, a five-layered MIM structure is provided. In this embodiment, the five-layered MIM structure further includes the second and third insulating layers, the
first metal layer 107 and thesecond metal layer 111 are made of silver, and the first insulatinglayer 109, the second insulating layer, and the third insulating layer are made of amorphous silicon. The thickness T1 is 20 nm, the thickness T2 is 352.8 nm, and the thickness T3 is 24 nm, and the second and third insulating layers have thicknesses of 77 nm and 96.8 nm, respectively. As a result, the total thickness of the five-layered MIM structure is about 571 nm, which is very thin. - Still referring to
FIG. 1A , a spacer layer (or dam) 117 is disposed on theMIM structure 115, and acavity 119 is surrounded by thespacer layer 117. Moreover, at least a portion of thephotoelectric conversion region 103 is not covered by thespacer layer 117, and thecavity 119 is disposed directly above the portion of thephotoelectric conversion region 103. In some embodiments, acover plate 121 is disposed on thespacer layer 117 and thecavity 119, and thecover plate 121 can be a transparent material. Specifically, thecover plate 121 may be made of glass, a transparent plastic material, or another suitable material. To sum up, thecavity 119 is enclosed by theMIM structure 115, thespacer layer 117 and thecover plate 121. Thespacer layer 117, thecavity 119 and thecover plate 121 compose amedium layer 130 a. - In some embodiments, the
spacer layer 117 may be made of inorganic materials, for example, silicon oxide, silicon nitride, silicon oxynitride, metal oxide or a combination thereof, organic polymer materials, for example, epoxy resin, polyimide, butylcyclobutene (BCB), parylene, polynaphthalenes, fluorocarbons or acrylates, a photoresist material or another suitable insulating material. Thecover plate 121 may be any suitable material, including, but not limited to, glass, plastic, acrylic, sapphire, and a combination thereof. In some embodiments, thecover plate 121 has a thickness T5, which is in a range from about 200 μm to about 500 μm. In addition, the refractive index of thecover plate 121 is about 1.55. - As shown in
FIG. 1A , theimage sensor package 100 a further includes anoptical filter 125 disposed on thecover plate 121. In some embodiments, theoptical filter 125 may be a blue-light-transmissive filter, a green-light-transmissive filter, a red-light-transmissive filter, or an infrared-transmissive filter. In some embodiments, theoptical filter 125 is made of a photoresist material and a pigment mixed in the photoresist material, and the photoresist material may be an organic material. Moreover, theoptical filter 125 has a thickness T6 which is in a range from about 1 μm to 20 μm, especially in a range from about 10 μm to about 20 μm. - In some embodiments, the thickness T5 of the
cover plate 121 is greater than the thickness T6 of theoptical filter 125, and the thickness T6 of theoptical filter 125 is greater than the total thickness T4 of theMIM structure 115. - The
image sensor package 100 a inFIG. 1A includes theoptical filter 125 and theMIM structure 115 disposed above thephotoelectric conversion region 103, and theoptical filter 125 and theMIM structure 115 are disposed on two opposite sides of themedium layer 130 a. Specifically, theMIM structure 115 is disposed between the photoelectric conversion region 103 and themedium layer 130 a. - The
optical filter 125 can absorb the light that is not expected to be transmitted to thephotoelectric conversion region 103, thereby the signal-to-noise (S/N) ratio can be increased. In other words, the transmission rate (also called transmittance) of the undesired light can be decreased by theoptical filter 125. Moreover, theMIM structure 115 can narrow the full width at half maximum (FWHM) of the light transmitted to thephotoelectric conversion region 103. As a result, theimage sensor package 100 a can produce a high signal-to-noise (S/N) ratio. Furthermore, theMIM structure 115 can help theimage sensor package 100 a to reduce the blue shift, and decrease the decay of the angular response at large angles of incidence. In addition, the size of theimage sensor package 100 a will not be increased too much since theMIM structure 115 is thin enough. - Referring to
FIG. 1B , a partial cross section of animage sensor package 100 b according to some embodiments is shown. In the embodiment ofFIG. 1B , thespacer layer 117 and thecavity 119 ofFIG. 1A are replaced by anadhesive layer 127, such as a transparent glue, and theadhesive layer 127 and thecover plate 121 compose amedium layer 130 b. In addition, the positions of theMIM structure 115 and theoptical filter 125 in the embodiment ofFIG. 1B are not changed from the embodiment ofFIG. 1A . In some embodiments, theMIM structure 115 is attached to thecover plate 121 by theadhesive layer 127. Some components of theimage sensor package 100 b are similar to those of theimage sensor package 100 a shown inFIG. 1A and are not repeated herein for simplicity. - Referring to
FIG. 1C , a partial cross section of animage sensor package 100 c according to some embodiments is shown. In the embodiment ofFIG. 1C , thecover plate 121 and theadhesive layer 127 ofFIG. 1B are replaced by amedium layer 123 which is made of a transparent material, and the transparent material has a refractive index in a range from about 1.2 to about 1.6. In addition, the positions of theMIM structure 115 and theoptical filter 125 in the embodiment ofFIG. 1C are not changed from the embodiment ofFIG. 1B . In some embodiments, themedium layer 123 has a thickness T7 which is in a range from about 100 μm to about 400 μm. The thickness T7 of themedium layer 123 is greater than the thickness T6 of theoptical filter 125, and the thickness T6 of theoptical filter 125 is greater than the total thickness T4 of theMIM structure 115. Some components of theimage sensor package 100 c are similar to those of theimage sensor package 100 b shown inFIG. 1B and are not repeated herein for simplicity. - Referring to
FIG. 1D , a partial cross section of animage sensor package 100 d according to some embodiments is shown. In comparison with theimage sensor package 100 b ofFIG. 1B , the positions of theMIM structure 115 and theoptical filter 125 are exchanged in theimage sensor package 100 d ofFIG. 1D . Specifically, theoptical filter 125 is sandwiched between the high-k film 105 on thephotoelectric conversion region 103 and theadhesive layer 127 under thecover plate 121. Moreover, theMIM structure 115 is disposed on thecover plate 121 of themedium layer 130 b. Some components of theimage sensor package 100 d are similar to those of theimage sensor package 100 b shown inFIG. 1B and are not repeated herein for simplicity. - Referring to
FIG. 1E , a partial cross section of animage sensor package 100 e according to some embodiments is shown. In comparison with theimage sensor package 100 c ofFIG. 1C , the positions of theMIM structure 115 and theoptical filter 125 are exchanged in theimage sensor package 100 e ofFIG. 1E . Specifically, theoptical filter 125 is sandwiched between the high-k film 105 on thephotoelectric conversion region 103 and themedium layer 123. Moreover, theMIM structure 115 is disposed on themedium layer 123. Some components of theimage sensor package 100 e are similar to those of theimage sensor package 100 c shown inFIG. 1C and are not repeated herein for simplicity. - Referring to
FIG. 1F , a partial cross section of animage sensor package 100 f according to some embodiments is shown. In the embodiment ofFIG. 1F , themedium layer 130 b of theimage sensor package 100 f is disposed on theoptical filter 125, and theMIM structure 115 is sandwiched between the high-k film 105 on thephotoelectric conversion region 103 and theoptical filter 125. Moreover, thecover plate 121 of themedium layer 130 b is attached on theoptical filter 125 by theadhesive layer 127. Some components of theimage sensor package 100 f are similar to those of theimage sensor package 100 b shown inFIG. 1B and are not repeated herein for simplicity. - Referring to
FIG. 2 , a cross section of animage sensor module 200 according to some embodiments is shown. In some embodiments, animage sensor package 100, which may be one of the image sensor packages 100 a, 100 b, 100 c, 100 d, 100 e, 100 f, is mounted on acircuit board 150 by a plurality of conductingstructures 160, such as solder balls, bumps or conductive pillars. Theimage sensor package 100 is electrically connected to thecircuit board 150 through the conductingstructures 160. - As shown in
FIG. 2 , theimage sensor module 200 further includes aholder 170, afilter 180 and alens 190. Theholder 170 has a capacity, so that thefilter 180 and thelens 190 are disposed within the capacity of theholder 170 and are fixed to theholder 170. Therefore, theimage sensor module 200 is a fixed-focus device. The capacity of theholder 170 can further accommodate theimage sensor package 100 on thecircuit board 150. Thefilter 180 in the capacity is located between thelens 190 and theimage sensor package 100, and there is a gap between thefilter 180 and theimage sensor package 100. In some embodiments, thefilter 180 is made of a light-transmissive material (such as glass) and a filter layer formed on the light-transmissive material. Specifically, thefilter 180 may be the cover plate ofFIG. 1A , and theholder 170 may be thespacer layer 117 ofFIG. 1A . In some embodiments, thefilter 180 is used to eliminate the image noise. Furthermore, thelens 190 can be formed by a single lens set or multiple lens sets. To simplify the diagram, onlyflat filter 180 andlens 190 are depicted herein. The structure of theimage sensor module 200 is determined by design requirements and is not limited thereto. For example, in other embodiments, theimage sensor module 200 can be a variable focus device. - Referring to
FIG. 3 , a diagram illustrating transmission characteristics of variousoptical filters 125 with different thicknesses according to some embodiments is shown. As mentioned previously, theoptical filter 125 can decrease the transmission rate of the light that is not expected to be transmitted to thephotoelectric conversion region 103 of theimage sensor package 100. For example, for animage sensor package 100 which is intended to be an infrared (IR) image sensor package, the visible light, which covers the range of wavelengths from about 380 nm to about 750 nm, is expected to be filtered out before reaching thephotoelectric conversion region 103 of the IR image sensor package. That is, the visible light cannot be transmitted to thephotoelectric conversion region 103 of the IR image sensor package, and the transmission rate of the visible light should be close to 0. In the embodiments provided below, an IR image sensor package is used to exemplify the properties of theimage sensor package 100 mentioned previously. - In the
image sensor package 100 which is intended to be an IR image sensor package, an infrared-transmissive filter is used as theoptical filter 125. The thicker the optical filter 125 (i.e. the infrared-transmissive filter) is, the lower transmission rate of the visible light it can reach. As shown inFIG. 3 , the optical filters 125 (i.e. the infrared-transmissive filter) with thicknesses of 20 μm and 7 μm can completely filter out the visible light of the incident light, while there are still a little bit of visible light passing though theoptical filter 125 with a thickness of 1 μm. - Referring to
FIG. 4A , a diagram illustrating normalized angular response characteristics of theMIM structure 115 according to some embodiments is shown. As mentioned previously, theMIM structure 115 can decrease the decay of the angular response at large angles of incidence. As shown inFIG. 4A , for the incident light which have a 940 nm wavelength, the value of the normalized angular response remains at 1 when the angle of incidence is in a range from 0 degree to about 15 degrees and the value of the normalized angular response slightly drops to about 0.95 when the angles of the incidence increase to 30 degrees. - Referring to
FIGS. 4B and 4C , simulated electric fields of theMIM structure 115 in the X-Z plane ofFIGS. 1A to 1F according to some embodiments are shown. Specifically,FIG. 4B shows the electric field distribution of theMIM structure 115 when the angle of incidence is 0 degree, andFIG. 4C shows the electric field distribution of theMIM structure 115 when the angle of incidence is 30 degrees. The width of thephotoelectric conversion region 103 is about 1 μm, which corresponds to the scale of the X-axis inFIGS. 4B and 4C . The location of thephotoelectric conversion region 103 is at Z=0, and the direction of incident light is from Z>0 to Z=0. In addition, the bar shown on the right hand side represents the electric field intensity, and the electric field intensity is measured in units of volts squared per meter squared (V/m)2. - As shown in
FIGS. 4B and 4C , the electric fields of the incident light are evenly dispersed in the region between Z=0.7 and Z=0, which indicated that the incident light can successfully reach thephotoelectric conversion region 103 of theimage sensor package 100. In addition, in comparison with the electric field distribution ofFIG. 4B , the electric field intensity ofFIG. 4C is only slightly decreased when the angle of incidence comes to 30 degrees. - Referring to
FIG. 5 , a diagram illustrating transmission characteristics of theMIM structure 115 according to some embodiments is shown. As mentioned previously, theMIM structure 115 can narrow the full width at half maximum (FWHM) of the light transmitted to thephotoelectric conversion region 103 and reduce the blue shift. As shown inFIG. 5 , the band widths of the transmission rates of the incident light are narrow, and the MIM structure 115 exhibits a very small blue shift, which is only 7 nm. - Referring to
FIGS. 6A and 6B , simulated electric fields of animage sensor package 100 in the X-Z plane ofFIGS. 1A to 1F according to some embodiments are shown. Specifically,FIG. 6A shows the electric field distribution of theimage sensor package 100 when the wavelength of the incident light is 670 nm, andFIG. 6B shows the electric field distribution of theimage sensor package 100 when the wavelength of the incident light is 940 nm. As mentioned earlier, the width of thephotoelectric conversion region 103 is about 1 μm, which corresponds to the scale of the X-axis inFIGS. 6A and 6B . The location of thephotoelectric conversion region 103 is at Z=0, and the direction of incident light is from Z>0 to Z=0. In addition, the bar shown on the right hand side represents the electric field intensity, and the electric field intensity is measured in units of volts squared per meter squared (V/m)2. - As shown in
FIG. 6A , the incident light with short wavelengths, such as 670 nm, is completely filtered out by theMIM structure 115 and theoptical filter 125 of theimage sensor package 100, which is intended to be an IR image sensor package. That is, the incident light with 670 nm wavelength is not transmitted to the photoelectric conversion region 103 (located at Z=0) of theimage sensor package 100. Apart from this, the incident light with long wavelengths, such as 940 nm in the IR region, is successfully transmitted to the photoelectric conversion region 103 (located at Z=0) of theimage sensor package 100 as shown inFIG. 6B . - Referring to
FIG. 7 , a diagram illustrating transmission characteristics of animage sensor package 100 according to some embodiments is shown. As mentioned previously, since theimage sensor package 100 includes aMIM structure 115 and anoptical filter 125, the transmission rate of the undesired light can be decreased (i.e. signal-to-noise (S/N) ratio can be increased), the full width at half maximum (FWHM) of the light expected to be transmitted to thephotoelectric conversion region 103 can be decreased (i.e. the band width of the transmitted light can be narrower). As a result, theimage sensor package 100 can produce a high signal-to-noise (S/N) ratio, which can be proved byFIG. 7 . In addition, the influence of blue shift can be reduced or prevented. For example, as shown inFIG. 7 , theimage sensor package 100 exhibits a very small blue shift, which is only 7 nm. - The foregoing outlines features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.
Claims (20)
1. An image sensor package, comprising:
a medium layer having a first surface and a second surface opposite to the first surface;
a metal-insulator-metal structure disposed on the first surface of the medium layer, wherein the metal-insulator-metal structure comprises a first metal layer, a first insulating layer, and a second metal layer, and the first insulating layer is disposed between the first metal layer and the second metal layer; and
an optical filter disposed on the second surface of the medium layer.
2. The image sensor package as claimed in claim 1 , wherein the optical filter is an infrared-transmissive, red-light-transmissive, green-light-transmissive or blue-light-transmissive filter.
3. The image sensor package as claimed in claim 1 , further comprising:
a semiconductor substrate having a photoelectric conversion region,
wherein the medium layer is disposed on the semiconductor substrate, and the metal-insulator-metal structure is disposed between the semiconductor substrate and the optical filter.
4. The image sensor package as claimed in claim 1 , further comprising:
a semiconductor substrate having a photoelectric conversion region,
wherein the medium layer is disposed on the semiconductor substrate, and the optical filter is disposed between the semiconductor substrate and the metal-insulator-metal structure.
5. The image sensor package as claimed in claim 1 , wherein the medium layer comprises a spacer layer, a cavity, and a transparent material, the transparent material is disposed between the spacer layer and the optical filter, and the cavity is enclosed by the spacer layer, the metal-insulator-metal structure and the transparent material.
6. The image sensor package as claimed in claim 1 , wherein the medium layer comprises an adhesive layer and a transparent material, and the transparent material is disposed on the adhesive layer.
7. The image sensor package as claimed in claim 6 , further comprising:
a semiconductor substrate having a photoelectric conversion region,
wherein the transparent material is disposed between the optical filter and the semiconductor substrate, and the adhesive layer is disposed on the metal-insulator-metal structure.
8. The image sensor package as claimed in claim 6 , further comprising:
a semiconductor substrate having a photoelectric conversion region,
wherein the transparent material is disposed between the metal-insulator-metal structure and the semiconductor substrate, and the adhesive layer is disposed on the optical filter.
9. The image sensor package as claimed in claim 1 , wherein the medium layer comprises a transparent material, and the transparent material has a refractive index in a range from 1.2 to 1.6.
10. The image sensor package as claimed in claim 9 , wherein the medium layer is disposed on the metal-insulator-metal structure, and the metal-insulator-metal structure is disposed between the medium layer and the semiconductor substrate.
11. The image sensor package as claimed in claim 9 , wherein the medium layer is disposed on the optical filter, and the optical filter is disposed between the medium layer and the semiconductor substrate.
12. The image sensor package as claimed in claim 1 , wherein the optical filter has a thickness in a range from 1 μm to 20 μm.
13. The image sensor package as claimed in claim 1 , wherein the thickness of the optical filter is in a range from 10 μm to 20 μm.
14. The image sensor package as claimed in claim 1 , wherein the first metal layer and the second metal layer are made of silver, and the first insulating layer is made of amorphous silicon.
15. The image sensor package as claimed in claim 1 , wherein the first metal layer has a first thickness, the second metal layer has a second thickness, the first insulating layer has a third thickness, and the third thickness is greater than the first thickness and the second thickness.
16. The image sensor package as claimed in claim 1 , wherein the metal-insulator-metal structure further comprises a second insulating layer and a third insulating layer, and the first metal layer, the first insulating layer and the second metal layer are disposed between the second insulating layer and the third insulating layer.
17. The image sensor package as claimed in claim 1 , further comprising:
a semiconductor substrate having a photoelectric conversion region; and
a high-k film disposed on the semiconductor substrate and covering the photoelectric conversion region, wherein the high-k film is disposed between the metal-insulator-metal structure and the semiconductor substrate.
18. The image sensor package as claimed in claim 17 , wherein the optical filter is disposed between the metal-insulator-metal structure and the high-k film.
19. The image sensor package as claimed in claim 1 , wherein the medium layer has a thickness which is greater than that of the metal-insulator-metal structure.
20. The image sensor package as claimed in claim 1 , wherein the optical filter has a thickness which is greater than that of the metal-insulator-metal structure.
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2017
- 2017-09-07 US US15/697,825 patent/US10224357B1/en active Active
- 2017-11-14 TW TW106139308A patent/TWI645556B/en active
- 2017-11-22 CN CN201711169370.8A patent/CN109473451B/en active Active
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CN109473451A (en) | 2019-03-15 |
JP2019050345A (en) | 2019-03-28 |
TW201913987A (en) | 2019-04-01 |
US10224357B1 (en) | 2019-03-05 |
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TWI645556B (en) | 2018-12-21 |
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