High-temperature-resistant flexible ultraviolet solar blind detector and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant flexible ultraviolet solar blind detector and a preparation method thereof, and particularly relates to the field of semiconductor devices. Comprising a substrate layer which is made of a high-temperature-resistant flexible metal sheet; the metal layer is positioned on the substrate layer; the insulating layer is positioned on the metal layer; the photosensitive layer is positioned on the insulating layer; and the electrode layer comprises an electrode which is in ohmic contact with the photosensitive layer. The method comprises the following steps: cleaning a metal sheet substrate; upwards depositing a metal layer, an insulating layer and a photosensitive layer on the surface of the substrate by using a magnetron sputtering method; and manufacturing the metal interdigital electrode on the photosensitive layer by spin coating, exposure and development. According to the technical scheme, the problem that a traditional rigid detector cannot have high temperature and structural flexibility at the same time is solved, and the detector has wide application prospects in the fields of military reconnaissance, environment monitoring and the like.

Description

Technical Field

[0001] The invention relates to the field of semiconductor devices, and in particular to a high-temperature resistant flexible ultraviolet solar-blind detection device and a preparation method thereof. Background Art

[0002] The wavelength of solar-blind ultraviolet light is between 10nm and 280nm. Due to the strong absorption of the atmosphere, ultraviolet light in this band can hardly penetrate the atmosphere to reach the earth's surface, which makes solar-blind ultraviolet detectors have the unique advantage of low background noise. This feature makes solar-blind ultraviolet detectors show great application potential in many fields, including but not limited to ozone hole monitoring, missile tracking and ultraviolet communication. With the advancement of science and technology and the increase in detection needs, the performance requirements for solar-blind ultraviolet detectors are becoming increasingly stringent, especially in terms of responsiveness, response time, detection wavelength range and the ability to adapt to harsh environments.

[0003] In harsh environments, such as fire monitoring and rocket tail flame detection, the detector must not only have high responsiveness, wide detection wavelength and fast response capabilities, but also be able to withstand high temperatures and maintain good flexibility. This is because these application scenarios are often accompanied by extremely high temperatures and complex spatial structures, and traditional rigid detectors are difficult to meet these requirements. Therefore, the development of a UV solar-blind detector that is both resistant to high temperatures and bendable has become a current research hotspot, and has broad application prospects in military reconnaissance, environmental monitoring and other fields. Summary of the invention

[0004] The present invention aims to provide a high temperature resistant flexible ultraviolet solar blind detection device and a preparation method thereof, which solves the problem that traditional rigid detectors cannot meet the requirements of both high temperature and structural flexibility.

[0005] In order to achieve the above object, the present invention provides a technical solution as follows: a high temperature resistant flexible ultraviolet solar blind detection device, comprising:

[0006] A substrate layer, wherein the substrate layer is made of a high temperature resistant flexible metal sheet;

[0007] a metal layer, wherein the metal layer is located on the substrate layer;

[0008] an insulating layer, wherein the insulating layer is located on the metal layer;

[0009] A photosensitive layer, wherein the photosensitive layer is located on the insulating layer;

[0010] The electrode layer includes an electrode that forms an ohmic contact with the photosensitive layer.

[0011] Furthermore, the metal foil substrate is a commercial copper foil with a thickness of 10-100 μm. The above material can be used as a substrate to withstand higher temperatures in photoelectric tests.

[0012] Furthermore, the metal layer is an Al film or a Cu film with a thickness of 100-200 nm, which can achieve high surface flatness requirements.

[0013] Furthermore, the insulating layer material is ultra-wide bandgap AlN, and its thickness is 100 nm, which can effectively prevent the transmission of carriers between the copper foil and Ga2O3.

[0014] Furthermore, the photosensitive layer is a-Ga2O3, and its thickness is 50-200nm.

[0015] Furthermore, the electrode layer material is metal Ni, and its thickness is 100-200nm.

[0016] Another technical solution provided by the present invention is as follows: a method for preparing a high temperature resistant flexible ultraviolet solar blind detection device, comprising the following steps:

[0017] S1, clean the metal substrate, then deposit a metal layer at high temperature to create a flat surface;

[0018] S2, depositing an insulating layer and a photosensitive layer upward on the surface of the metal layer by using a magnetron sputtering method;

[0019] S3. The interdigital electrode layer is manufactured on the photosensitive layer by spin coating, exposure, development and sputtering.

[0020] Furthermore, in step S1, the specific conditions of magnetron sputtering are: the sputtering gas is high-purity argon, the sputtering power is 60W, and the back vacuum is less than 5.0×10 -4 Pa, the growth pressure is 0.7 Pa; the sputtering target is Al metal target or Cu metal target, and the growth temperature is 500℃.

[0021] Furthermore, in step S2, the specific conditions of magnetron sputtering are: the sputtering gas is high-purity argon, the sputtering power is 80W, and the back vacuum is less than 5.0×10 -4 Pa, and the growth pressure is 2Pa; the sputtering target material of the insulating layer is AlN ceramic target, and the sputtering target material of the photosensitive layer is Ga2O3 ceramic target.

[0022] Furthermore, in step S3, the sputtering target is a Ni metal target, the growth temperature is room temperature, the size of the interdigital electrode pattern on the detection device is 400 μm×600 μm, and the width of the interdigital electrode pattern is 10 μm.

[0023] Compared with the prior art, this solution has the following beneficial effects:

[0024] 1. This detector has made a major breakthrough in high temperature resistance and flexibility, and can maintain high performance in extreme environments, broadening the application scenarios. By optimizing the preparation process, the responsiveness is improved and the response time is shortened, achieving faster and more accurate detection of ultraviolet solar blind light signals.

[0025] 2. This detector achieves wide-band solar-blind ultraviolet light detection by regulating the oxygen vacancy concentration in the a-Ga2O3 film, improving the accuracy and comprehensiveness of detection. The relatively simple and low-cost preparation process reduces the production cost, which is conducive to the mass production and wide application of the detector.

[0026] 3. In the test, the detector device showed stable photoelectric response in the temperature range from room temperature to 200℃ and in the bending state of different curvature radii. In particular, under the irradiation of ultraviolet light with a wavelength of 250nm, the photocurrent of the detector device remained basically unchanged, while the dark current gradually increased with the increase of temperature. However, even at the highest test temperature, the ratio of the photocurrent to the dark current of the detector device was still greater than 10 2 , indicating that it has good signal-to-noise ratio and detection sensitivity. At the same time, multiple IV tests have verified the consistency of the detection performance of the detection device at different temperatures, further proving its reliability and stability in practical applications. Therefore, the detection device has broad application prospects in military reconnaissance, environmental monitoring and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the structure of the detection device of this embodiment;

[0028] Figure 2 is the IV curve of the detection device of this embodiment in the dark state and under the light of wavelength 250nm;

[0029] Figure 3 This is a trend diagram of the photocurrent and dark current of the detection device tested at different curvature radii in this embodiment;

[0030] Figure 4 This is a statistical diagram of dark current and photocurrent of the detection device tested at different curvature radii at 5V;

[0031] Figure 5 It is a trend diagram of dark current and photocurrent of the detection device implemented at different temperatures when the curvature R is fixed at 1.5;

[0032] Figure 6 This is a statistical diagram of the dark current and photocurrent of the detection device at different temperatures under 5V bias when the curvature R is fixed at 1.5. DETAILED DESCRIPTION

[0033] The detection device of this embodiment is highly sensitive to day-blind ultraviolet light of 200-280nm wavelength. When ultraviolet light irradiates the photosensitive layer, the photons excite the electrons in the semiconductor material, causing them to transition from the valence band to the conduction band, forming electron-hole pairs. These electron-hole pairs are separated under the action of the electric field and collected by the interdigital electrodes to form photocurrent. At the same time, the insulator layer plays a role of isolation and protection, preventing the loss and interference of electrons during the transmission process.

[0034] Example

[0035] like Figure 1 As shown, a high temperature resistant flexible ultraviolet solar blind detection device comprises:

[0036] A substrate layer, the substrate layer is made of a high temperature resistant flexible metal sheet;

[0037] A metal layer, wherein the metal layer is located on the substrate layer;

[0038] An insulating layer, the insulating layer is located on the metal layer;

[0039] A photosensitive layer, wherein the photosensitive layer is located on the insulating layer;

[0040] The electrode layer includes an electrode that forms an ohmic contact with the photosensitive layer.

[0041] A method for preparing a high temperature resistant flexible ultraviolet solar blind detection device comprises the following steps:

[0042] S1. Clean the metal substrate. In this embodiment, a commercial copper foil with a thickness of 20 μm and a size of 2.5 cm×2.5 cm is selected as the base. The copper foil is ultrasonically cleaned with acetone, alcohol and deionized water, and then blown dry with nitrogen. A metal layer with a thickness of 100-200 nm is sputtered upward on the surface of the metal substrate by magnetron sputtering. The specific preparation conditions of the metal layer are as follows: Back vacuum: less than 5.0×10 -4 Pa; sputtering gas: high-purity argon; growth pressure: 0.7Pa; sputtering target: Al target or Cu target; sputtering power: 60W; substrate temperature: 500℃.

[0043] S2. Then, a 100 nm thick AlN insulating layer is sputtered upward on the surface of the metal layer by magnetron sputtering. The specific preparation conditions of the insulating layer film are as follows: the back vacuum is less than 5.0×10 -4Pa; sputtering gas: high-purity argon (Ar); growth pressure: 2Pa; sputtering target: AlN ceramic target; sputtering power: 80W; substrate temperature: room temperature. After the AlN insulating layer is sputtered, an α-Ga2O3 film with a thickness of about 50-200nnm is sputtered upward on the surface of the insulating layer; the specific preparation conditions of the α-Ga2O3 film are as follows: back vacuum: less than 5.0×10 -4 Pa; sputtering gas: high purity argon (Ar); growth pressure: 2Pa; sputtering target: Ga2O3 ceramic target; sputtering power: 80W; substrate temperature: room temperature.

[0044] S3. After the deposition of a-Ga2O3 film is completed, the interdigital electrodes are prepared. Spin-coat the photoresist on the Ga2O3 film. The specific parameters of this step are: spin coating speed 1 is 600r / min, speed 1 time is 6s, spin coating speed 2 is 4000r / min, speed 2 time is 6s, pre-bake 25min, exposure 24s, development 23s; then expose and develop, rinse with deionized water, and blow dry the sample with a nitrogen gun. After the photolithography is completed, sputter metal Ni on the pattern as the interdigital electrode. The size of the interdigital electrode pattern is 400μm×600μm, and the width of the middle finger is 10μm. The specific parameters of Ni plating are: back vacuum: less than 5.0×10 -4 Pa; sputtering gas: high purity argon (Ar); growth pressure: 1Pa; sputtering target: Ni metal target; sputtering power: 60W; substrate temperature: room temperature.

[0045] The following experiments were carried out using the detection device prepared by the above method:

[0046] Figure 2 It is the IV curve of the detector in the dark state and under the light of 250nm wavelength. Figure 2 It can be seen that the ratio of the photocurrent to the dark current of the detection device at 5V exceeds 10 2 , proving that the detection device has good detection performance.

[0047] To evaluate the optoelectronic performance of the detector device at high temperature and in a bent state, the detector device was bent to a curvature radius of 1.0 cm, 1.5 cm, and 1.8 cm, and its optoelectronic performance was tested without heating. Subsequently, the device was heated in a certain bending state and its optoelectronic performance was tested again. All tests were performed using a copper foil substrate with a size of 25 mm × 25 mm.

[0048] like Figure 3The IV test results of the detection device under different curvature bending states are presented. The test covers two parts: photocurrent and dark current. The photocurrent test is carried out under a light source with a wavelength of 250nm. The test results show that the photocurrent values ​​of the device under different curvature bending conditions show small differences from each other. In order to ensure the reliability of the test results, the detection device was subjected to multiple IV tests, and the current values ​​under 5V voltage were statistically analyzed. The statistical results are as follows: Figure 4 Analysis shows that even in a bent state, the photoelectric performance of the detector does not change significantly, and the ratio of photocurrent to dark current remains above 100, proving that the detector has good reliability under different curvatures.

[0049] The photoresponse characteristics of the detector under high temperature environment were studied in depth. During the test, the detector kept the bending radius at 1.5cm and the test temperature was set at 100℃ and 200℃ respectively. Figure 5 In the photocurrent test, the wavelength of the light source used was 250nm and the light intensity was fixed at 274μW / cm 2 . Figure 5 It is revealed that as the test temperature gradually increases, the dark current of the detection device shows an upward trend, while the photocurrent remains basically stable.

[0050] In order to verify the consistency of the detection performance of the detector at different test temperatures, the photocurrent and dark current of the detector were measured multiple times at various temperatures, and the statistical data of the light and dark current of the detector under 5V voltage are presented in Figure 6 From the statistical results, it can be observed that as the test temperature increases, the ratio of the photocurrent to the dark current of the detection device decreases due to the increase of the dark current. However, even at the minimum ratio, the ratio of the photocurrent to the dark current is still greater than 10 2 , indicating that the detection performance of the detection device is still stable and reliable in high temperature environment.

[0051] The above are only embodiments of the present invention, and the common knowledge such as the known specific structures and / or characteristics in the scheme are not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A high temperature resistant flexible UV solar blind detection device, characterized in that: include: A substrate layer, wherein the substrate layer is made of a high temperature resistant flexible metal sheet; A metal layer, wherein the metal layer is located on the substrate layer; an insulating layer, wherein the insulating layer is located on the metal layer; A photosensitive layer, wherein the photosensitive layer is located on the insulating layer; The electrode layer includes an electrode that forms an ohmic contact with the photosensitive layer.

2. The high temperature resistant flexible UV solar blind detection device according to claim 1, characterized in that: The high temperature resistant flexible metal substrate material is commercial copper foil with a thickness of 10-100 μm.

3. The high temperature resistant flexible ultraviolet solar blind detection device according to claim 1, characterized in that: The metal layer material is metal Al or Cu, and its thickness is 100-200nm.

4. The high temperature resistant flexible UV solar blind detection device according to claim 1, characterized in that: The insulating layer is made of ultra-wide bandgap AlN, and its thickness is 100 nm.

5. The high temperature resistant flexible UV solar blind detection device according to claim 1, characterized in that: The photosensitive layer is a-Ga2O3, and its thickness is 50-200nm.

6. The high temperature resistant flexible UV solar blind detection device according to claim 1, characterized in that: The electrode layer material is metal Ni, and its thickness is 100-200nm.

7. A method for preparing a high temperature resistant flexible ultraviolet solar blind detection device, characterized in that: The steps include: S1, clean the metal substrate, then deposit a metal layer at high temperature to create a flat surface; S2, depositing an insulating layer and a photosensitive layer upward on the surface of the metal layer by using a magnetron sputtering method; S3, forming an interdigitated electrode layer on the photosensitive layer by spin coating, exposure and development.

8. The method for preparing a high temperature resistant flexible ultraviolet solar blind detection device according to claim 7, characterized in that: In step S1, the specific conditions of magnetron sputtering are: the sputtering gas is high-purity argon, the sputtering power is 60W, and the back vacuum is less than 5.0×10 -4 Pa, the growth pressure is 0.7 Pa; the sputtering target is Al metal target or Cu metal target, and the growth temperature is 500°C.

9. The method for preparing a high temperature resistant flexible ultraviolet solar blind detection device according to claim 7, characterized in that: In step S2, the specific conditions of magnetron sputtering are: the sputtering gas is high-purity argon, the sputtering power is 80W, and the back vacuum is less than 5.0×10 -4 Pa, and the growth pressure is 2Pa; the sputtering target material of the insulating layer is AlN ceramic target, and the sputtering target material of the photosensitive layer is Ga2O3 ceramic target.

10. The method for preparing a high temperature resistant flexible ultraviolet solar blind detection device according to claim 7, characterized in that: In step S3, the sputtering target is a Ni metal target, the growth temperature is room temperature, the size of the interdigital electrode pattern on the detection device is 400 μm×600 μm, and the width of the interdigital electrode pattern is 10 μm.

Images