CN110926604A - Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film - Google Patents
Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film Download PDFInfo
- Publication number
- CN110926604A CN110926604A CN201911220957.6A CN201911220957A CN110926604A CN 110926604 A CN110926604 A CN 110926604A CN 201911220957 A CN201911220957 A CN 201911220957A CN 110926604 A CN110926604 A CN 110926604A
- Authority
- CN
- China
- Prior art keywords
- detection unit
- photo
- thin film
- niobium
- chromium
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 138
- QVZNQFNKKMMPFH-UHFFFAOYSA-N chromium niobium Chemical compound [Cr].[Nb] QVZNQFNKKMMPFH-UHFFFAOYSA-N 0.000 title claims abstract description 43
- 229910021542 Vanadium(IV) oxide Inorganic materials 0.000 title claims abstract description 38
- GRUMUEUJTSXQOI-UHFFFAOYSA-N vanadium dioxide Chemical compound O=[V]=O GRUMUEUJTSXQOI-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 238000005057 refrigeration Methods 0.000 claims abstract description 7
- 239000010409 thin film Substances 0.000 claims description 66
- 239000010408 film Substances 0.000 claims description 55
- 239000000758 substrate Substances 0.000 claims description 31
- 239000010955 niobium Substances 0.000 claims description 20
- 238000004544 sputter deposition Methods 0.000 claims description 10
- 229910052697 platinum Inorganic materials 0.000 claims description 7
- 239000004065 semiconductor Substances 0.000 claims description 7
- 229910052737 gold Inorganic materials 0.000 claims description 6
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 229910052782 aluminium Inorganic materials 0.000 claims description 3
- 238000001451 molecular beam epitaxy Methods 0.000 claims description 3
- 238000004549 pulsed laser deposition Methods 0.000 claims description 3
- 238000004528 spin coating Methods 0.000 claims description 3
- 230000004044 response Effects 0.000 abstract description 15
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 abstract description 10
- 229910001935 vanadium oxide Inorganic materials 0.000 abstract description 10
- 238000009776 industrial production Methods 0.000 abstract description 2
- 239000000463 material Substances 0.000 description 22
- 230000008859 change Effects 0.000 description 20
- 239000012855 volatile organic compound Substances 0.000 description 18
- 238000005286 illumination Methods 0.000 description 17
- 239000013078 crystal Substances 0.000 description 15
- 230000003287 optical effect Effects 0.000 description 15
- 238000000034 method Methods 0.000 description 14
- 238000005516 engineering process Methods 0.000 description 12
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 11
- 238000002360 preparation method Methods 0.000 description 11
- 230000008569 process Effects 0.000 description 9
- 239000010936 titanium Substances 0.000 description 9
- 238000013461 design Methods 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 150000001875 compounds Chemical class 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 238000009413 insulation Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 239000013077 target material Substances 0.000 description 3
- 229910002244 LaAlO3 Inorganic materials 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910002370 SrTiO3 Inorganic materials 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Inorganic materials O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 229910052593 corundum Inorganic materials 0.000 description 2
- 238000011161 development Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000004377 microelectronic Methods 0.000 description 2
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 238000000059 patterning Methods 0.000 description 2
- 229910001845 yogo sapphire Inorganic materials 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000577 Silicon-germanium Inorganic materials 0.000 description 1
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910021417 amorphous silicon Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009529 body temperature measurement Methods 0.000 description 1
- 238000012512 characterization method Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000010970 precious metal Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J9/00—Measuring optical phase difference; Determining degree of coherence; Measuring optical wavelength
Abstract
The invention discloses a photo-thermal detection unit based on a chromium-niobium co-doped vanadium dioxide epitaxial film. The chromium-niobium co-doped vanadium dioxide epitaxial film is used as the photosensitive layer, and compared with the traditional vanadium oxide (comprising multiple phases such as vanadium dioxide) photo-thermal detection unit, the chromium-niobium co-doped vanadium dioxide epitaxial film has the advantages of high linearity, small hysteresis, wide temperature response range, wavelength discrimination and the like; compared with the current commercialized photo-thermal detector, the photo-thermal detection unit has a simple structure and is easy for industrial production; meanwhile, the photo-thermal detector is non-refrigeration, does not need a low-temperature working environment, and can be applied to a microbolometer or a temperature sensor and the like.
Description
Technical Field
The invention belongs to the two technical fields of electronic information and new materials, and relates to a sensor and a process technology of a sensitive component in the field of electronic information, a new semiconductor material preparation and application technology in the field of new materials, a new photoelectron material preparation and application technology, a new material preparation and application technology for an intelligent sensor and the like. The invention particularly relates to a photothermal detection unit based on a chromium-niobium co-doped vanadium dioxide epitaxial film, which has high linearity, low hysteresis, wide response range and wavelength resolution.
Background
The photoelectric detection technology has wide application in the fields of industrial production and control, consumer electronics, automobiles and the like, and the most important hardware part in the photoelectric detection process is as follows: photoelectric, photo-thermo-electric detecting unit or sensor. According to the working principle of the detecting unit or sensor, there can be divided into a photon type detector and a thermal type detector, in which: the photon type detectors are divided into a photoconductive detector, a photovoltaic detector and a photoelectron emission detector; the thermosensitive detectors are classified into pyroelectric detectors, thermopile detectors and microbolometer detectors. Among the thermosensitive detectors, the microbolometer detector is compatible with a CMOS integrated circuit in the manufacturing process, low in cost, capable of being produced in a large scale, excellent in performance, easy to operate and free of chopping, becomes a photo-thermal detector which is fastest in development and wide in application prospect at present, and has important application particularly in the field of infrared detection.
Since the uncooled microbolometer can be used under normal conditions without applying a low temperature, the uncooled microbolometer is most widely used. At present, there are many materials for preparing non-refrigeration microbolometers, which are mainly divided into: metal thin films and semiconductor thin films. The metal thin film is made of platinum, copper, nickel, titanium and the like, and is not obtained in practice due to low resistivity and small temperature coefficient of resistanceThe use of these precious metal materials is extensive and expensive for large scale applications. And Vanadium Oxide (VO)X) Thin films of compound semiconductors such as silicon germanium alloys, amorphous silicon and the like are used in uncooled microbolometers in a large number of applications, particularly as vanadium oxide thin film materials. The resistance value of the vanadium oxide resistor is generally controlled to be between several kilohms and hundreds of kilohms, and the vanadium oxide resistor shows good Temperature Coefficient of Resistance (TCR), and can generally reach-2%/DEG C. In addition, the vanadium oxide film resistor and the reading circuit have good matching performance, so that the design and optimization of a system structure are facilitated, and the advantages make vanadium oxide one of the preferred materials of the uncooled microbolometer detector. Wherein, VO2The film shows good TCR performance, can reach the level of minus 67%/DEG C, and is always a hot material for domestic and foreign research. However, VO2The use of thin films as non-refrigerated microbolometer detector materials also presents several challenges: (I) VO2The phase change temperature of the film is too low, so that the temperature detection range is narrow; secondly, in the phase change region, the resistance curve has obvious hysteretic characteristics, so that the linearity of the TCR curve is poor; (III) VO2The thin film has poor resolution of light wavelengths. These disadvantages and shortcomings greatly hinder VO2The application of the film is in pace.
In summary, the following steps: the traditional material used as the photo-thermal-electric detector is too high in cost and is not beneficial to large-scale application; the compound semiconductor thin film material becomes a candidate material of the non-refrigeration type although VO is typically represented therein2The film has obvious advantages, but also has the defects of narrow detection range, poor linearity, large temperature hysteresis and the like.
Disclosure of Invention
In order to avoid the defects of the prior art, the invention provides a photo-thermal detection unit based on a chromium-niobium co-doped vanadium dioxide epitaxial film to improve VO (volatile organic compounds)2The epitaxial film is used as the linearity of a non-refrigeration type photo-thermal detector, widens the measurement range, reduces the temperature hysteresis, and further overcomes the defect of Vanadium Oxide (VO)X) The disadvantages and shortcomings of the uncooled microbolometer material represented by the thin film.
In order to achieve the purpose, the invention adopts the following technical scheme:
the utility model provides a light and heat detection unit based on chromium-niobium codope vanadium dioxide epitaxial film which characterized in that: the photo-thermal detection unit is of a laminated structure and sequentially comprises a substrate layer, a thin film layer grown on the substrate layer and an electrode layer arranged on the thin film layer from bottom to top; the electrode layer is provided with an electrode lead wire for connecting an external circuit;
the film layer is a chromium-niobium co-doped vanadium dioxide epitaxial film and is used as a photosensitive layer of the photo-thermal detection unit, and the film layer can absorb light to generate heat so as to increase the temperature, so that the resistance value of the film layer is reduced; the electrode layer is used for measuring the resistance value of the thin film layer and sending the resistance value into an external circuit through an electrode lead, and then the photo-thermal detection function is achieved.
Further, the selection principle of the substrate layer is as follows: the thin film layer can realize epitaxial growth on the substrate layer. For example, the substrate layer is preferably low-cost aluminum oxide (Al)2O3) The crystal can be perovskite single crystal SrTiO3、LaAlO3Etc., or hexagonal symmetrical GaN, ZnO single crystal, or cubic symmetrical Si, ZrO2Single crystals, and the like.
Further, the substrate layer has a good insulation property, such as an intrinsic semiconductor or an insulator, so as to facilitate the readout of the resistance signal of the thin film layer, such as Al with a specific selective high insulation property2O3A single crystal as the substrate layer.
Furthermore, the thickness of the substrate layer is 0.1 mm-1 mm, and the upper part of the substrate layer can be mechanically supported.
Further, the chromium-niobium co-doped vanadium dioxide epitaxial film is VxCryNbzO2The doping proportion is calculated according to the atomic ratio, x is 0.70-0.85, y is 0.10-0.20, z is 0.02-0.10, and x + y + z is 1. If the atomic ratio of x 0.75, y 0.17 and z 0.08 can be selected, the chromium-niobium co-doped V is prepared0.75Cr0.17Nb0.08O2And (3) epitaxial thin films.
Further, the chromium-niobium co-doped vanadium dioxide epitaxial film is obtained by growing on the surface of the substrate layer through sputtering, pulsed laser deposition, molecular beam epitaxy or spin coating. For example, a high-quality chromium-niobium co-doped vanadium dioxide epitaxial film can be prepared by a selective sputtering method.
Furthermore, the thickness of the thin film layer is 20-300 nm so as to ensure the sufficient absorption of light. The thickness of the thin film layer may be set to 100nm, for example.
The invention selects chromium-niobium codoped VO2Epitaxial film of VO with higher doping rate than undoped VO2The epitaxial film has better resistance-temperature linearity (the linear range of the logarithmic resistance-temperature can reach-190 ℃ to 120 ℃), and smaller hysteresis temperature (undoped VO)2The gyration temperature of the epitaxial film is above 10 ℃ in the phase change region; chromium-niobium co-doped VO2The gyration temperature of the epitaxial film is reduced to below 2 ℃ in the phase change region, even no gyration temperature) and a wider measurement range.
Further, the chromium-niobium co-doped vanadium dioxide epitaxial film has the capability of distinguishing the wavelength of external incident light. For example, the wavelength of the detection light can be distinguished according to different responses of the resistance of the photo-thermal detection unit to different wavelengths (different slopes of the resistance-power relationship).
Further, ohmic contact is formed between the electrode layer and the thin film layer, and good conductivity is further guaranteed. The electrode layer is preferably made of Al with low cost, and can also be made of Cu, Pt/Ti or Au/Ti electrodes and the like, and is used for reading the resistance of the photo-thermal detection unit. The thickness of the electrode layer is 20-200 nm.
Further, the electrode layer may be formed by patterning through a microelectronic process. For example, a mask may be used to form the electrode layer in four regions.
Furthermore, the electrode lead preferably adopts low-cost Al, and can also be made of electrode lead materials such as Pt, Au and the like, and the signal of the photo-thermal detection unit is sent into an external circuit to complete the signal detection function.
Compared with the prior art, the invention has the beneficial effects that:
1. the photo-thermal detection unit is a non-refrigeration type detection unit, does not need a low-temperature working environment, and is easy to apply; the photo-thermal detection unit has the advantages of simple structure, small volume and easy integration, and can form a large-scale detection array.
2. The photo-thermal detection unit selects chromium-niobium co-doped VO2Compared with the traditional undoped vanadium oxide or vanadium dioxide detection unit, the epitaxial thin film has higher linearity, smaller hysteresis temperature, wider temperature measurement range and wavelength resolution capability.
3. The invention is based on chromium-niobium co-doped VO2Compared with the traditional undoped vanadium oxide or vanadium dioxide detection unit, the photoelectric detection unit of the epitaxial film can normally work in a temperature-variable environment (-190-120 ℃).
Drawings
Fig. 1 is a three-dimensional schematic view of a photothermal detection unit according to the present invention.
FIG. 2 is a schematic side view of a photothermal detection unit of the present invention.
Fig. 3 is a schematic view of preparing a chromium-niobium co-doped vanadium dioxide epitaxial film by using a sputtering technique in embodiment 1 of the present invention.
FIG. 4 shows V obtained in example 1 of the present invention0.75Cr0.17Nb0.08O2An XRD diffraction pattern of the epitaxial thin film, wherein figure 4(a) is an out-of-plane symmetric XRD diffraction pattern, and figure 4(b) is an in-plane XRD diffraction pattern.
Fig. 5 is a resistance-temperature curve of the photothermal detection unit according to example 1 of the present invention.
FIG. 6 shows the VO doping and undoped VO in example 1 of the present invention2Resistance-temperature curve of the photo-thermal detection unit of the epitaxial thin film.
FIG. 7 shows VO in accordance with doped (corresponding to FIG. 7(a)) and undoped (corresponding to FIG. 7(b)) in example 2 of the present invention2The relationship between the resistance value of the photo-thermal response and the incident illumination power of the photo-thermal detection unit of the epitaxial film under the condition of room temperature (25 ℃).
FIG. 8 shows VO in accordance with example 3 of the present invention based on doping (corresponding to FIG. 8(a)) and undoped (corresponding to FIG. 8((b)) thereof2The resistance value of the photo-thermal response and the incident light of the photo-thermal detection unit of the epitaxial film are under the condition of 50 DEG CThe relationship between the illumination powers.
FIG. 9 shows VO in accordance with example 4 of the present invention based on doping (corresponding to FIG. 9(a)) and undoped (corresponding to FIG. 9(b))2The relationship between the resistance value of the photo-thermal response and the incident illumination power of the photo-thermal detection unit of the epitaxial film under the condition of 60 ℃.
FIG. 10 shows VO in accordance with doped (corresponding to FIG. 10(a)) and undoped (corresponding to FIG. 10(b)) in example 5 of the present invention2The relationship between the resistance value of the photo-thermal response of the epitaxial thin film photo-thermal detection unit and the incident illumination power is realized at 70 ℃.
FIG. 11 shows VO of example 6 based on doping (corresponding to FIG. 11(a)) and undoped (corresponding to FIG. 11(b)) in accordance with the present invention2The relationship between the resistance value of the photo-thermal response of the epitaxial thin film photo-thermal detection unit and the incident illumination power is determined under the condition of 80 ℃.
Fig. 12 shows the relationship between the resistance value of the photothermal response and the incident illumination power of the photothermal detection unit based on the chromium-niobium co-doped vanadium dioxide epitaxial thin film in the embodiment 7 of the invention under the illumination conditions with different wavelengths.
FIG. 13 is a schematic diagram of an array detector based on a Cr-Nb codoped vanadium dioxide epitaxial thin film photothermal detection unit in example 8 of the invention.
Reference numbers in the figures: 1 is a substrate layer; 2 is a thin film layer; 3 is an electrode layer; and 4, an electrode lead.
Detailed Description
In order that the structural features and technical advantages of the present invention will be more clearly understood, the present invention will be described in further detail with reference to the following examples. It should be understood that the specific embodiments described below are only for illustrating the present invention and are not to be construed as limiting the present invention.
Research finds that the main factors restricting the development of the photo-thermal-electric detector technology are: the traditional materials, such as noble metals like Pt, are high in cost and not beneficial to large-scale application; (II) the TCR of the traditional material is smaller, which results in low sensitivity of the device; the compound semiconductor thin film material becomes a candidate material of a non-refrigeration type photo-thermal-electric detector, but some materials have narrow detection range, poor linearity and large temperature hysteresis, and are still under research or optimizationAnd (5) stage. Based on the above consideration, the invention proposes to utilize chromium-niobium co-doped VO2The process and the technology for preparing the photo-thermal detection unit by the epitaxial film can widen the measurement range and the linearity of the photo-thermal-electric detection unit and reduce the temperature hysteresis, and the invention also provides a method for distinguishing the wavelength of external incident light.
The photothermal detection unit provided by the invention is a laminated structure as shown in fig. 1 and fig. 2, and sequentially comprises a substrate layer 1, a thin film layer 2 epitaxially grown on the substrate layer 1, and an electrode layer 3 arranged on the thin film layer 2 from bottom to top; the electrode layer 3 is provided with an electrode lead 4 for connecting an external circuit;
the thin film layer 2 is a chromium-niobium co-doped vanadium dioxide epitaxial thin film and is used as a photosensitive layer of the photo-thermal detection unit, and the photosensitive layer can absorb light to generate heat so as to increase the temperature, so that the resistance value of the thin film layer 2 is reduced; the electrode layer 3 is used for measuring the resistance value of the thin film layer 2, and a four-electrode method is generally adopted to eliminate contact resistance; the electrode lead 4 is connected into an external circuit, the resistance change condition is analyzed, the optical power is detected, and the photo-thermal detection function is further realized. Furthermore, the detection unit distinguishes the wavelengths by their response differences to illumination of different wavelengths.
According to an embodiment of the present invention, the substrate layer 1 is preferably low-cost aluminum oxide (Al)2O3) The crystal can be perovskite single crystal SrTiO3、LaAlO3Isohexagonal or hexagonal symmetrical GaN, ZnO single crystal and cubic symmetrical Si, ZrO2Single crystals, and the like. The selection principle is as follows: chromium-niobium co-doped VO2The epitaxial thin film can realize epitaxial growth on the substrate layer. For example, one embodiment of the present invention is to use (0001) -oriented Al2O3The single crystal serves as a substrate layer.
According to an embodiment of the present invention, the substrate layer needs to have good insulation property to facilitate reading of the thin film resistance signal. For example, one embodiment of the present invention selects Al having high insulating properties2O3The single crystal serves as a substrate layer.
According to one embodiment of the present invention, a substrateThe thickness of the layer crystal is 0.1 mm-1 mm, and the upper part of the layer crystal can be mechanically supported. For example, in one embodiment of the present invention, 0.5mm thick Al is selected2O3The single crystal is used as a substrate layer to realize mechanical support for all layers on the substrate layer.
According to one embodiment of the invention, the chromium-niobium co-doped vanadium dioxide epitaxial film is VxCryNbzO2. The doping proportion is calculated according to the atomic ratio, x is 0.70-0.85, y is 0.10-0.20, z is 0.02-0.10, and x + y + z is 1. For example, in one embodiment of the invention, the atomic ratio of x ═ 0.75, y ═ 0.17 and z ═ 0.08 is selected to prepare high-quality chromium-niobium codoped V0.75Cr0.17Nb0.08O2And (3) epitaxial thin films.
According to an embodiment of the present invention, the thin film layer may be formed by sputtering, pulsed laser deposition, molecular beam epitaxy, spin coating, and the like. For example, one embodiment of the invention selects a sputtering method to prepare the chromium-niobium codoped V0.75Cr0.17Nb0.08O2And (3) epitaxial thin films.
According to an embodiment of the present invention, the thickness of the thin film layer is 20 to 300nm, and the sufficient thickness can ensure the absorption of light. For example, in one embodiment of the invention, the thickness of the chromium-niobium co-doped vanadium dioxide epitaxial film is selected to be 100 nm;
according to one embodiment of the invention, chromium-niobium co-doped VO2Epitaxial film of VO with higher doping rate than undoped VO2The epitaxial film has better resistance-temperature linearity, smaller hysteresis and wider measurement range, wherein the logarithmic resistance-temperature linearity range can reach as follows: -190 ℃ to 120 ℃. For example, in one embodiment of the present invention, V0.75Cr0.17Nb0.08O2The linear range of the logarithmic resistance-temperature curve of the epitaxial film is-33 ℃ to 120 ℃, and almost no temperature hysteresis exists in a phase change region.
According to one embodiment of the invention, chromium-niobium co-doped VO2The hysteretic temperature of the epitaxial film is higher than that of the undoped VO in the phase change region2EpitaxyThe temperature of the film is reduced to below 2 ℃ above 10 ℃, and even no stagnation temperature exists. For example, one embodiment of the present invention shows V0.75Cr0.17Nb0.08O2The epitaxial film has good photo-thermal detection function in the phase change region at 50 ℃, 60 ℃, 70 ℃ and 80 ℃.
According to one embodiment of the invention, chromium-niobium co-doped VO2The epitaxial film has the resolution capability on the wavelength of external incident light, and the resistance of the photo-thermal detection unit has different responses (different slopes of resistance-power relation) on different wavelengths of light, so that the wavelength of the detection light is resolved. For example, in one embodiment of the present invention, the photothermal detection unit can well distinguish between two different colors of light, 532nm and 633 nm.
According to an embodiment of the present invention, the electrode layer is preferably made of Al with low cost, and may be a Cu, Pt/Ti or Au/Ti electrode, etc. for reading the resistance of the photo-thermal detecting unit.
According to an embodiment of the present invention, the thickness of the electrode layer is 20 to 200 nm. For example, in one embodiment of the present invention, an electrode layer thickness of 20nm is selected.
According to an embodiment of the present invention, the electrode layer may be formed by patterning through a microelectronic process. For example, in one embodiment of the present invention, a mask is used to form the electrode layer in four regions.
According to one embodiment of the invention, the electrode layer and the thin film layer are in ohmic contact, so that good conductivity is ensured. For example, in one embodiment of the invention, a Pt/Ti composite electrode (Pt is 20nm thick and Ti is 10nm thick) is selected as an electrode layer, so that ohmic contact between the electrode layer and a thin film layer can be well ensured;
according to an embodiment of the present invention, the electrode lead is preferably made of low-cost Al, or Pt, Au, or other electrode lead materials, and sends the signal of the photo-thermal detection unit to an external circuit to complete the signal detection function. For example, in one embodiment of the present invention, Au wires are selected as electrode leads to introduce the photothermal detection unit signals into the external circuit.
The present invention is further described below with reference to specific embodiments to make the principle, technical solutions and technical effects of the present invention more clear.
Example 1
In this example, 0.5mm thick (0001) oriented Al was selected2O3The single crystal is used as a substrate layer, and the area size is 10mm multiplied by 10 mm. And (3) growing a Cr-Nb co-doped vanadium dioxide film by utilizing a magnetron sputtering technology, wherein the doping proportion of V to Cr to Nb is 0.75 to 0.17 to 0.08. The sputtering growth conditions were: the target material is an alloy target material with corresponding proportion of V, Cr and Nb, argon and oxygen are used as a mixed gas reaction source, the target material is ionized and bombarded under the action of a radio frequency power source, and ions or beam groups sputtered out are deposited on a substrate under the action of an electric field to form a film as shown in figure 3. The flow rates of argon and oxygen are respectively 50sccm and 1.5sccm, the growth pressure is 0.3Pa, the growth temperature is 525 ℃, the sputtering power is 65W, the growth time is 40 minutes, and the corresponding film thickness is 100 nm. In addition, as shown in fig. 3, a sputtering mode from bottom to top is adopted, so that on one hand, the uniformity of the film is ensured, and on the other hand, the formation of large particles in the film can be avoided, the quality of the film is damaged, and the preparation of the photo-thermal detection unit is not facilitated.
In order to better understand the preparation method of the photothermal detection unit of the present invention, the present example performs microstructure characterization on the Cr-Nb co-doped vanadium dioxide thin film. FIG. 4 is V0.75Cr0.17Nb0.08O2An XRD diffraction pattern of the epitaxial thin film, wherein: FIG. 4(a) is an out-of-plane symmetric diffraction pattern, found to have only V0.75Cr0.17Nb0.08O2(020) And (040) out-of-plane diffraction peaks, other diffraction peaks being from the substrate layer, indicating that the film is highly oriented in the out-of-plane direction; FIG. 4(b) is an in-plane XRD scan showing V0.75Cr0.17Nb0.08O2(220) Peak has 6-fold symmetry with substrate layer Al2O3(208) The peaks form a 30 ° spacing, indicating that the film is also highly oriented in-plane. Therefore, the present embodiment provides a method for preparing a thin film layer of a photo-thermal detection unit, which is the basis for further preparing the detection unit.
In order to better understand the method for manufacturing the photothermal detection unit of the present invention, four electrodes were manufactured on the prepared thin film using a mask. A Pt/Ti composite electrode (Pt is 20nm thick and Ti is 10nm thick) is selected as an electrode layer to avoid the influence of contact resistance, and an Au system is used as an electrode lead to be connected with the electrode layer to form the photo-thermal detection unit. FIG. 5 shows that the resistance-temperature relationship of the photothermal detection unit is measured by using a transport system, the tested temperature change interval is 240K to 390K, the change range is 150K, the conversion temperature is-33.15 ℃ to 116.85 ℃, the change range is 150 ℃, and the logarithmic resistance-temperature change curve is similar to a straight line and very accords with the linear requirement of the detector design. In addition, the resistance change curve of the temperature rise and the temperature drop are approximately superposed, and the adverse effect of the hysteretic noise on the performance of the photo-thermal detection unit is greatly reduced.
In order to better understand the preparation method and performance of the chromium-niobium co-doped vanadium dioxide epitaxial film photothermal detection unit, the same sputtering method and process technology are adopted, and the undoped vanadium dioxide epitaxial film photothermal detection unit is prepared in the embodiment. Fig. 6 is a resistance versus temperature curve for doped and undoped detection cells, comparing: undoped VO at elevated temperature2The resistance of the epitaxial film starts to drop sharply from 320K to 360K (phase change region), and the change curve of the logarithmic resistance relative to the temperature presents strong nonlinearity; at the time of cooling, undoped VO2The resistance of the epitaxial film starts to rise sharply from 360K to 320K (phase change region), the change curve of the logarithmic resistance relative to the temperature also presents strong nonlinearity, and the change curve of the temperature-rising resistance and the change curve of the temperature-falling resistance in the region present temperature hysteresis up to 10K and do not meet the basic requirements of the design of the detector. While the chromium-niobium codoped VO in this example2In the epitaxial thin film photo-thermal detection unit, a logarithmic resistance-temperature change curve presents excellent linear characteristics, and almost no temperature hysteresis exists in the range of 240K to 390K. Therefore, the detection range of the chromium-niobium co-doped vanadium dioxide epitaxial film photothermal detection unit is greatly widened, and particularly, the photothermal detection unit provided by the invention can still work in a high-temperature section, so that the detection unit is applied to oneAnd lays a foundation for high-temperature environments.
Example 2
The present embodiment is the variation relationship between the resistance and incident light power of the undoped and doped photo-thermal detection units at room temperature (25 ℃). The photo-thermal detection units of example 1 were used both undoped and doped. As shown in fig. 7(a) and (b), the resistance value and the optical power of the photothermal detection unit in both cases show a good linear relationship at room temperature, indicating that the photothermal detection unit proposed by the present invention can be used as a light detection unit or device, a temperature sensor, and the like.
Example 3
The present embodiment is the variation relationship between the resistance and incident light power of the undoped and doped photo-thermal detecting units at 50 ℃. The photo-thermal detection units of example 1 were used both undoped and doped. As shown in fig. 8(a), the doped photothermal detection unit exhibits a good linear relationship between the resistance value and the optical power at 50 ℃, which indicates that the doped photothermal detection unit provided by the present invention can be used as a light detection unit or device, a temperature sensor, etc. However, as shown in fig. 8(b), the resistance value and the optical power of the undoped photo-thermal detection unit are no longer in a linear relationship, and the linear relationship between the resistance value and the optical power cannot be satisfied, and thus the undoped photo-thermal detection unit cannot be applied to the fields of the photo-detection unit, the device, the temperature sensing, and the like.
Example 4
The present embodiment is the relationship between the resistance of the undoped and doped photo-thermal detecting units at 60 ℃ and the power of the incident light. The photo-thermal detection unit of example 1 was used in the undoped case; the doping case adopts V0.73Cr0.19Nb0.08O2The epitaxial thin film photothermal detection unit, the thin film and the detection unit thereof adopt the same preparation technology and process as those of the embodiment 1. As shown in fig. 9(a), the doped photothermal detection unit exhibits a good linear relationship between the resistance value and the optical power at 60 ℃, which indicates that the doped photothermal detection unit provided by the present invention can be used as a light detection unit or device, a temperature sensor, etc. However, as shown in FIG. 9(b),the resistance value and the optical power of the undoped photo-thermal detection unit are not in a linear relation any more, the linear relation between the resistance and the optical power cannot be met, and the undoped photo-thermal detection unit cannot be applied to the fields of photo-detection units or devices, temperature sensing and the like.
Example 5
The present embodiment shows the variation relationship between the resistance and incident light power of the undoped and doped photo-thermal detecting units at 70 ℃. The photo-thermal detection unit of example 1 was used in the undoped case; the doping case adopts V0.78Cr0.14Nb0.08O2The epitaxial thin film photothermal detection unit, the thin film and the detection unit thereof adopt the same preparation technology and process as those of the embodiment 1. As shown in fig. 10(a), the doped photothermal detection unit exhibits a better linear relationship between the resistance value and the optical power at 70 ℃, indicating that the doped photothermal detection unit proposed by the present invention can be used as a light detection unit or device, a temperature sensor, etc. However, as shown in fig. 10(b), the resistance value and the optical power of the undoped photo-thermal detection unit are no longer in a linear relationship, and the linear relationship between the resistance value and the optical power cannot be satisfied, and thus the undoped photo-thermal detection unit cannot be applied to the fields of the photo-detection unit, the device, the temperature sensing, and the like.
Example 6
The present embodiment is the relationship between the resistance of the undoped and doped photo-thermal detecting units at 80 ℃ and the power of the incident light. The photo-thermal detection unit of example 1 was used in the undoped case; the doping case adopts V0.8Cr0.15Nb0.05O2The epitaxial thin film photothermal detection unit, the thin film and the detection unit thereof adopt the same preparation technology and process as those of the embodiment 1. As shown in fig. 11(a), the doped photothermal detection unit exhibits a better linear relationship between the resistance value and the optical power at 80 ℃, which indicates that the doped photothermal detection unit provided by the present invention can be used as an optical detection unit or device, a temperature sensor, etc. However, as shown in fig. 11(b), the resistance value and the optical power of the undoped photo-thermal detection unit are no longer linear, and the linear relationship between the resistance value and the optical power cannot be satisfied, so that the undoped photo-thermal detection unit cannot be applied to the photo-detection unit or the device, and the temperatureSensing, and the like.
Therefore, in comparison with examples 2 to 6, it can be easily found that the photo-thermal detection unit prepared based on the chromium-niobium co-doped vanadium dioxide epitaxial film has the advantages of good linearity, small hysteresis temperature, wide working temperature range and the like under various doping ratios.
Example 7
In order to better understand the preparation method and performance of the chromium-niobium co-doped vanadium dioxide epitaxial thin film photo-thermal detection unit, the embodiment utilizes the chromium-niobium co-doped vanadium dioxide epitaxial thin film photo-thermal detection unit to detect the photo-thermal-electric response performance under two different color illumination conditions. With the doped photo-thermal detection unit of example 1, the relationship between the resistance of the photo-thermal response and the incident illumination power under different wavelengths of illumination is shown in fig. 12, and it can be seen that the photo-thermal detection unit has different responses under different wavelengths of illumination, and although the photo-thermal detection unit has a good linear relationship between the resistance and the power, the two straight lines have different slopes. As shown in FIG. 12, in the case of illumination (laser light) at 532nm, the slope of the resistance-power relationship line was-91.16. omega./mW; the slope of the resistance versus power line is-72.98 Ω/mW under 633nm illumination (laser). It can be seen that under different wavelength illumination conditions, the difference (different slopes) of the responses of the photothermal detection unit can be used to distinguish the illumination wavelength.
Example 8
In order to better understand the preparation method and performance of the chromium-niobium co-doped vanadium dioxide epitaxial thin film photothermal detection unit and provide design guidance for possible application of the invention, the embodiment provides a design idea of an array detector based on the photothermal detection unit. FIG. 13 is a schematic diagram of an array detector based on a co-doped vanadium dioxide epitaxial thin film detection unit. The detector is composed of photo-thermal detection units arranged in a 4 x 4 rectangular mode, a four-electrode configuration is configured, and contact resistance is reduced. The photothermal detection signal of each detection unit is introduced into an external processing circuit through four electrode leads, and the external illumination condition is imaged through analysis, so that the photothermal detection unit based on the invention can be applied to a detector area array.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.
Claims (10)
1. The utility model provides a light and heat detection unit based on chromium-niobium codope vanadium dioxide epitaxial film which characterized in that: the photo-thermal detection unit is of a laminated structure and sequentially comprises a substrate layer (1), a thin film layer (2) growing on the substrate layer (1) and an electrode layer (3) arranged on the thin film layer (2) from bottom to top; the electrode layer (3) is provided with an electrode lead (4) for connecting an external circuit;
the thin film layer (2) is a chromium-niobium co-doped vanadium dioxide epitaxial thin film and is used as a photosensitive layer of a photo-thermal detection unit, and the chromium-niobium co-doped vanadium dioxide epitaxial thin film can absorb light to generate heat so as to increase the temperature, so that the resistance value of the thin film layer (2) is reduced; the electrode layer (3) is used for measuring the resistance value of the thin film layer (2) and is sent into an external circuit through an electrode lead (4), and then the photo-thermal detection function is achieved.
2. The photothermal detection unit according to claim 1, wherein: the substrate layer (1) is an insulating substrate or a semiconductor substrate which can realize epitaxial growth of the thin film layer (2), and the thickness of the substrate layer (1) is 0.1-1 mm.
3. The photothermal detection unit according to claim 1, wherein: the chromium-niobium co-doped vanadium dioxide epitaxial film is VxCryNbzO2The doping proportion is calculated according to the atomic ratio, x is 0.70-0.85, y is 0.10-0.20, z is 0.02-0.10, and x + y + z is 1.
4. The photothermal detection unit according to claim 1 or 3, wherein: the chromium-niobium co-doped vanadium dioxide epitaxial film is obtained by epitaxial growth on the surface of the substrate layer (1) through sputtering, pulsed laser deposition, molecular beam epitaxy or spin coating.
5. The photothermal detection unit according to claim 1 or 3, wherein: the thickness of the thin film layer (2) is 20-300 nm.
6. The photothermal detection unit according to claim 1 or 3, wherein: the chromium-niobium co-doped vanadium dioxide epitaxial film has the capability of distinguishing the wavelength of external incident light.
7. The photothermal detection unit according to claim 1, wherein: and ohmic contact is formed between the electrode layer (3) and the thin film layer (2).
8. The photothermal detection unit of claim 7, wherein: the thickness of the electrode layer (3) is 20-200 nm; the electrode layer is an Al, Cu, Pt/Ti or Au/Ti electrode.
9. The photothermal detection unit according to claim 1, wherein: the electrode lead (4) is an Al, Pt or Au lead.
10. The photothermal detection unit according to claim 1, wherein: the photo-thermal detection unit is a non-refrigeration type detection unit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911220957.6A CN110926604A (en) | 2019-12-03 | 2019-12-03 | Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911220957.6A CN110926604A (en) | 2019-12-03 | 2019-12-03 | Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110926604A true CN110926604A (en) | 2020-03-27 |
Family
ID=69848470
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911220957.6A Pending CN110926604A (en) | 2019-12-03 | 2019-12-03 | Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110926604A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114485949A (en) * | 2022-01-27 | 2022-05-13 | 鸿海精密工业股份有限公司 | Microbolometer and method for manufacturing the same |
| CN115988956A (en) * | 2023-01-31 | 2023-04-18 | 北京大学 | Superlattice Mott phase change device with adjustable phase change temperature |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101881667A (en) * | 2010-06-24 | 2010-11-10 | 电子科技大学 | Uncooled microbolometer and preparation method thereof |
| CN103022177A (en) * | 2013-01-11 | 2013-04-03 | 四川汇源科技发展股份有限公司 | Uncooled pyroelectric infrared detector and preparation method thereof |
| CN103540903A (en) * | 2013-10-21 | 2014-01-29 | 中国科学院上海硅酸盐研究所 | Low-temperature high-resistance temperature coefficient non-heat stagnation thin-film material and preparation method thereof |
| CN104276603A (en) * | 2013-07-08 | 2015-01-14 | 中国科学院上海硅酸盐研究所 | Method for adjusting band gap of vanadium dioxide film |
| CN107915258A (en) * | 2017-11-03 | 2018-04-17 | 畅的新材料科技（上海）有限公司 | A kind of vanadium oxide nano material of nearly room temperature phase-change and preparation method thereof |
| CN109449239A (en) * | 2018-09-26 | 2019-03-08 | 北京镓族科技有限公司 | Gallic acid lanthanum film and its manufacturing method and corresponding lanthanum gallate film photoelectric detector |
-
2019
- 2019-12-03 CN CN201911220957.6A patent/CN110926604A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101881667A (en) * | 2010-06-24 | 2010-11-10 | 电子科技大学 | Uncooled microbolometer and preparation method thereof |
| CN103022177A (en) * | 2013-01-11 | 2013-04-03 | 四川汇源科技发展股份有限公司 | Uncooled pyroelectric infrared detector and preparation method thereof |
| CN104276603A (en) * | 2013-07-08 | 2015-01-14 | 中国科学院上海硅酸盐研究所 | Method for adjusting band gap of vanadium dioxide film |
| CN103540903A (en) * | 2013-10-21 | 2014-01-29 | 中国科学院上海硅酸盐研究所 | Low-temperature high-resistance temperature coefficient non-heat stagnation thin-film material and preparation method thereof |
| CN107915258A (en) * | 2017-11-03 | 2018-04-17 | 畅的新材料科技（上海）有限公司 | A kind of vanadium oxide nano material of nearly room temperature phase-change and preparation method thereof |
| CN109449239A (en) * | 2018-09-26 | 2019-03-08 | 北京镓族科技有限公司 | Gallic acid lanthanum film and its manufacturing method and corresponding lanthanum gallate film photoelectric detector |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114485949A (en) * | 2022-01-27 | 2022-05-13 | 鸿海精密工业股份有限公司 | Microbolometer and method for manufacturing the same |
| CN115988956A (en) * | 2023-01-31 | 2023-04-18 | 北京大学 | Superlattice Mott phase change device with adjustable phase change temperature |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Wang et al. | Nanostructured vanadium oxide thin film with high TCR at room temperature for microbolometer | |
| US4969956A (en) | Transparent thin film thermocouple | |
| Kumar et al. | Pulsed laser deposited vanadium oxide thin films for uncooled infrared detectors | |
| JP4592826B2 (en) | Radiation detector and radiation detection method | |
| Zerov et al. | Heat-sensitive materials for uncooled microbolometer arrays | |
| CN110926604A (en) | Photo-thermal detection unit based on chromium-niobium co-doped vanadium dioxide epitaxial film | |
| JP2010109073A (en) | Infrared detecting element and sensor, and method of manufacturing infrared detecting element | |
| CN109269662A (en) | Rare-earth Ni-base perovskite oxide thermistor material applied to infrared acquisition | |
| CN102832286B (en) | Two-operation-mode ultraviolet detector with vertical structure and preparation method thereof | |
| KR20150009772A (en) | Fabrication method of high quality oxide thin films for micribolometer | |
| Karunagaran et al. | Study of a pulsed laser deposited vanadium oxide based microbolometer array | |
| Lee et al. | Detectivity of thin-film NTC thermal sensors | |
| CN103852171B (en) | A kind of non-brake method Long Wave Infrared Probe absorbent layer structure | |
| JP4574746B2 (en) | Radiation detector and radiation detection method | |
| US6292089B1 (en) | Structures for temperature sensors and infrared detectors | |
| CN105734504B (en) | One kind mixes silver vanadium oxide thermosensitive material film and preparation method thereof | |
| Le Bourdais et al. | Epitaxial manganite freestanding bridges for low power pressure sensors | |
| CN203772418U (en) | Absorbing layer structure for non-refrigerating long-wave infrared detector | |
| Cole et al. | High performance infrared detector arrays using thin film microstructures | |
| Bruchhaus et al. | Sputtering of PZT thin films for surface micromachined IR-detector arrays | |
| Wang et al. | Research on VO x uncooled infrared bolometer based on porous silicon | |
| RU82934U1 (en) | BOLOMETRIC RADIATION RECEIVER | |
| Reddy et al. | Bolometric properties of oxygen atmosphere annealed Nb: TiO2− x films for infrared detectors | |
| JP3727208B2 (en) | Temperature-sensitive resistance change film, manufacturing method thereof, and far-infrared sensor using the same | |
| KR20090059799A (en) | Resistive materials for microbolometer, method for preparation of resistive materials and microbolometer containing the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20200327 |