Terahertz photoconductive antenna and manufacturing method thereof

Abstract

The invention provides a terahertz photoconductive antenna and a manufacturing method thereof. A germanium-carbon functional layer and a first bonding layer are sequentially formed on a semiconductor substrate, a diamond substrate is provided, a second bonding layer is formed on the diamond substrate, the semiconductor substrate is turned to enable the first bonding layer to face the second bonding layer, and the semiconductor substrate and the diamond substrate are bonded. The semiconductor substrate is removed, an electrode is formed on the germanium-carbon functional layer, and therefore manufacturing of the terahertz photoconductive antenna is achieved, the substrate of the formed terahertz photoconductive antenna is the diamond substrate, the overall temperature of a terahertz device is effectively reduced, the thermal breakdown risk of the terahertz device is reduced, and the reliability of the terahertz device is improved. In addition, due to the germanium-carbon functional layer, the terahertz device has the advantages of higher carrier mobility, wider band gap, better heat conductivity, higher radiation resistance and the like, the germanium-carbon functional layer is initially formed on the semiconductor substrate and then transferred to the diamond substrate, the germanium-carbon functional layer has large size and extremely high film forming quality, and the performance of the terahertz device is improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, and in particular to a terahertz photoconductive antenna and a manufacturing method thereof. Background Art

[0002] Terahertz waves have a wavelength range of 3-1000μm and a frequency range of 0.1-10THz. They have the characteristics of broadband, low energy, high penetration, coherence and transient properties, and show great application potential in many fields. As one of the most promising terahertz devices, terahertz photoconductive antennas have attracted widespread attention from researchers. Conventional terahertz photoconductive emitters and detectors are made of low-temperature-GaAs (LT) semiconductor materials. The specific reasons are as follows: ultra-short carrier lifetime, high resistivity and high carrier mobility. High-quality photoconductive semiconductor substrate materials are the basis for the development of advanced terahertz photoconductive antennas. The development of related technologies is expected to promote the application of terahertz photoconductive antenna technology in security inspection, counter-terrorism, biomedicine, atmospheric remote sensing, space astronomy, satellite observation and military fields.

[0003] Currently, the mainstream LT-GaAs terahertz photoconductive antennas are mostly formed on high-cost semi-insulating GaAs (Semi-Insulating, SI) wafers, and SI-GaAs wafers are small in size and the manufacturing cost of the devices is expensive. Therefore, it is urgent to develop a new type of terahertz photoconductive material technology for the manufacture of terahertz photoconductive antennas. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a terahertz photoconductive antenna and a manufacturing method thereof, so as to reduce the manufacturing cost of the terahertz photoconductive antenna and improve its performance.

[0005] The present invention provides a method for manufacturing a terahertz photoconductive antenna, comprising:

[0006] forming a germanium-carbon functional layer and a first bonding layer in sequence on a semiconductor substrate;

[0007] providing a diamond substrate, on which a second bonding layer is formed;

[0008] Turning over the semiconductor substrate so that the first bonding layer faces the second bonding layer, and bonding the semiconductor substrate to the diamond substrate;

[0009] removing the semiconductor substrate;

[0010] An electrode is formed on the germanium carbon functional layer.

[0011] Optionally, the germanium-carbon functional layer includes a germanium-carbon layer, a quantum well structure layer including a germanium-carbon layer, or a superlattice structure layer including a germanium-carbon layer.

[0012] Optionally, the carbon content in the germanium-carbon functional layer does not exceed 5%.

[0013] Optionally, the quantum well structure layer or superlattice structure layer includes alternately stacked barrier layers and potential well layers, the germanium carbon layer serves as the barrier layer, and the material of the potential well layer includes germanium tin, silicon germanium tin, silicon germanium or germanium.

[0014] Optionally, the thickness of the germanium-carbon functional layer is in the range of 100-3000 nm;

[0015] The thickness of the barrier layer in the quantum well structure is ≥10nm, the thickness of the potential well layer is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

[0016] Optionally, the material of the semiconductor substrate includes silicon, germanium or germanium carbon;

[0017] When the material of the semiconductor substrate includes silicon, before forming the germanium-carbon functional layer on the semiconductor substrate, the method further includes: forming a buffer layer on the semiconductor substrate, wherein the material of the buffer layer includes a low-temperature germanium buffer layer and a high-temperature germanium buffer layer;

[0018] The removing of the semiconductor substrate includes: removing the semiconductor substrate and the buffer layer.

[0019] Optionally, the material of the first bonding layer and the second bonding layer is amorphous silicon.

[0020] The present application also provides a terahertz photoconductive antenna comprising:

[0021] Diamond substrate;

[0022] A second bonding layer, a first bonding layer and a germanium-carbon functional layer sequentially stacked on the diamond substrate;

[0023] The electrode on the germanium carbon functional layer.

[0024] Optionally, the germanium-carbon functional layer includes a germanium-carbon layer, a quantum well structure layer including a germanium-carbon layer, or a superlattice structure layer including a germanium-carbon layer.

[0025] Optionally, the carbon content in the germanium-carbon functional layer does not exceed 5%.

[0026] Optionally, the quantum well structure layer or superlattice structure layer includes alternately stacked barrier layers and potential well layers, the germanium carbon layer serves as the barrier layer, and the material of the potential well layer includes germanium tin, silicon germanium tin, silicon germanium or germanium.

[0027] Optionally, the thickness of the germanium-carbon functional layer is in the range of 100-3000 nm;

[0028] The thickness of the barrier layer in the quantum well structure is ≥10nm, the thickness of the potential well layer is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

[0029] Optionally, the material of the first bonding layer and the second bonding layer is amorphous silicon.

[0030] The present application provides a terahertz photoconductive antenna and a manufacturing method thereof, wherein a germanium-carbon functional layer and a first bonding layer are sequentially formed on a semiconductor substrate, a diamond substrate is provided, a second bonding layer is formed on the diamond substrate, the semiconductor substrate is flipped so that the first bonding layer faces the second bonding layer, the semiconductor substrate and the diamond substrate are bonded, the semiconductor substrate is removed, and an electrode is formed on the germanium-carbon functional layer, thereby realizing the manufacturing of the terahertz photoconductive antenna. Since the substrate of the formed terahertz photoconductive antenna is a diamond substrate, the heat generated in the device can be quickly conducted to the heat dissipation system, thereby effectively reducing the overall temperature of the terahertz device and reducing the risk of thermal breakdown of the terahertz device. In addition, the germanium-carbon functional layer enables the terahertz device to have advantages such as higher carrier mobility, wider band gap, better thermal conductivity, and stronger radiation resistance. The germanium-carbon functional layer is initially formed on the semiconductor substrate and then transferred to the diamond substrate. It has a large size and extremely high film quality, which is conducive to improving the performance of the terahertz device and reducing the manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A schematic diagram of the manufacturing process of a terahertz photoconductive antenna provided in an embodiment of the present application;

[0033] Figure 2-Figure 14 A schematic diagram of the structure of a terahertz photoconductive antenna during the manufacturing process provided in an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present application, but the present application may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0036] This application is described in detail with reference to schematic diagrams. When describing the embodiments of this application in detail, for the sake of convenience, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of this application. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0037] In order to better understand the technical solution and technical effects of the present application, specific embodiments will be described in detail below with reference to the accompanying drawings.

[0038] See also Figure 1 FIG. 1 is a schematic diagram of a manufacturing process of a terahertz photoconductive antenna provided in an embodiment of the present application, referring to FIG. Figure 2-Figure 14 , is a schematic diagram of the structure of a terahertz photoconductive antenna in a manufacturing process provided by an embodiment of the present application. The method may include:

[0039] S101, forming a germanium carbon functional layer and a first bonding layer 140 on the semiconductor substrate 100 in sequence, referring to Figure 2 and Figure 3 shown.

[0040] In the embodiment of the present application, the semiconductor substrate 100 can provide support for the film layer thereon. It has the characteristics of low cost and large size, and is easy to reduce the production cost of terahertz devices. A germanium-carbon functional layer is formed on the semiconductor substrate 100, which can be formed by an epitaxial process. Its thickness is controlled by the epitaxial process, thereby meeting the needs of terahertz photoconductive antennas.

[0041] The material of the semiconductor substrate 100 may be silicon, germanium or germanium carbon. When the material of the semiconductor substrate 100 is germanium carbon, a film layer with a partial thickness of the germanium carbon substrate may be used as a germanium carbon functional layer. When the material of the semiconductor substrate 100 is silicon, before forming the germanium carbon functional layer on the semiconductor substrate 100, a buffer layer may be formed on the semiconductor substrate 100. The material of the buffer layer includes a low-temperature germanium buffer layer 110 and a high-temperature germanium buffer layer 120. Figure 2 and Figure 3 As shown, in order to solve the problem of lattice adaptation caused by directly forming a germanium carbon functional layer on a silicon substrate, thereby causing the germanium carbon functional layer to have low quality. The thickness of the low-temperature germanium buffer layer ranges from 100 to 500 nm, and the thickness of the high-temperature germanium buffer layer ranges from 1000 to 1500 nm.

[0042] The germanium carbon functional layer includes a germanium carbon layer 131, Figure 2 or a germanium-carbon functional layer including a composite structure layer 132 of a germanium-carbon layer, reference Figure 3 As shown, the composite structure layer 132 includes a quantum well structure layer of a germanium carbon layer or a superlattice structure layer including a germanium carbon layer, and the composite structure layer 132 includes an alternately stacked barrier layer 13A and a well layer 13B, the germanium carbon layer is used as the barrier layer 13A, and the material of the well layer 13B includes germanium tin, silicon germanium tin, silicon germanium or germanium, etc. That is, the quantum well structure layer includes alternately stacked GeSn / GeC, GeC / SiGeSn, GeC / GeSi or GeC / Ge, etc., and the superlattice structure layer includes alternately stacked GeSn / GeC, GeC / SiGeSn, GeC / GeSi or GeC / Ge, etc.

[0043] Compared with Ge terahertz devices, GeC terahertz devices may have advantages such as higher carrier mobility, wider band gap, better thermal conductivity, and stronger radiation resistance. Si-based GeC materials have outstanding advantages such as large wafer size, low manufacturing cost, compatibility with SiCMOS process, and easy mass production. They are considered to be one of the important alternatives to LT-GaAs terahertz technology. The germanium carbon functional layer can be formed at low temperature, so it can also be called low-temperature germanium carbon layer (LT-GeC).

[0044] The carbon content in the germanium carbon functional layer does not exceed 5%, that is, ≤5%. The thickness of the germanium carbon functional layer is in the range of 100-3000nm. The thickness of the barrier layer 13A in the quantum well structure is ≥10nm, the thickness of the potential well layer 13B is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer 13A in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer 13B is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

[0045] When the germanium carbon functional layer only includes the germanium carbon layer 131, the formed device is called a bulk germanium carbon device. When the germanium carbon functional layer includes a quantum well structure layer, the formed device is called a quantum well device. When the germanium carbon functional layer includes a superlattice structure layer, the formed device is called a superlattice device.

[0046] Compared with bulk germanium carbon devices, superlattice devices with superlattice structure layers as active areas have the following advantages: 1) Adjustable conductivity: The superlattice structure is composed of different materials stacked together. By changing the number of lattice layers, the conductivity of the photoconductive material can be adjusted, so that the superlattice can better match different working conditions and requirements in the photoconductive antenna; 2) Wide frequency adaptation range: Since the superlattice structure uses a variety of materials, each layer of material has different conductivity, so the superlattice can work at different frequencies. This allows the photoconductive antenna to maintain high efficiency in a wider frequency range and is suitable for more diverse application scenarios; 3) Fast response speed: The superlattice structure can achieve fast electron transfer and response, which helps to improve the signal transmission speed and response sensitivity; 4) Good thermal stability: The superlattice structure usually has high thermal conductivity and thermal stability, which can effectively disperse and discharge the heat generated inside the antenna to prevent performance degradation or damage due to overheating.

[0047] Compared with bulk germanium carbon devices, quantum well devices with quantum well structure layers as active regions have the following advantages: 1) Large band edge state density: The band edge state density of LT-GeC quantum wells is much greater than that of bulk LT-GeC materials, which is conducive to improving differential gain, thereby improving the modulation bandwidth and output stability of photoconductive antennas; 2) Strong electron confinement: The LT-GeC quantum well structure has a stronger confinement effect on electrons, which helps to improve injection efficiency and reduce threshold current. This enables LT-GeC quantum well photoconductive antennas to achieve efficient photoelectric conversion at lower operating currents; 3) Good thermal stability: LT-GeC quantum wells have a higher characteristic temperature than bulk materials, which means that under the same operating conditions, photoconductive antennas with LT-GeC quantum well structures have better thermal stability and reliability; 4) Fine wavelength control: By adjusting parameters such as the well width and barrier height of the LT-GeC quantum well, fine control of the output wavelength of the LT-GeC photoconductive antenna can be achieved. This is of great significance for application scenarios that require specific wavelength output; 5) Low non-radiative recombination rate: The LT-GeC quantum well structure helps to reduce the non-radiative recombination rate, improve the photoelectric conversion efficiency, and help improve the brightness and coherence of the light source.

[0048] The material of the first bonding layer 140 can be amorphous silicon, and the thickness thereof is in the range of 5-20 nm. The first bonding layer 140 can be formed by low temperature growth.

[0049] S102, providing a diamond substrate 200, on which a second bonding layer 210 is formed, referring to Figure 4 shown.

[0050] The inventors have found through research that the current mainstream Ge-related photoconductive antennas have serious heat dissipation problems, the main reasons for which include heat generation, the influence of high bias voltage, changes in material properties, and the risk of thermal breakdown. Therefore, effective heat dissipation measures need to be taken to ensure the stable operation of the photoconductive antenna and extend its service life.

[0051] Therefore, in the embodiment of the present application, a diamond substrate 200 may be provided. Diamond has extremely high thermal conductivity and is one of the crystals with the highest thermal conductivity among solid materials. In the range of 30-650°C, the thermal conductivity of diamond far exceeds that of other materials. As the final substrate of the terahertz device, the diamond substrate 200 can quickly conduct the heat generated in the device to the heat dissipation system, thereby effectively reducing the overall temperature of the terahertz device and reducing the risk of thermal breakdown of the terahertz device.

[0052] The material of the second bonding layer 210 can be amorphous silicon, and the thickness thereof is in the range of 5-20 nm. The second bonding layer 210 can be formed by low temperature growth.

[0053] S103, flipping the semiconductor substrate 100 so that the first bonding layer 140 faces the second bonding layer 210, and bonding the semiconductor substrate 100 and the diamond substrate 200, referring to Figure 5-8 shown.

[0054] The semiconductor substrate 100 is flipped over so that the first bonding layer 140 faces the second bonding layer 210, and the first bonding layer 140 and the second bonding layer 210 are bonded together, so that the semiconductor substrate 100 and the diamond substrate 200 can be bonded. At this time, the first bonding layer 140 and the second bonding layer 210 and the germanium carbon functional layer are all located on the diamond substrate 200, and the transfer of the germanium carbon functional layer is achieved. The germanium carbon functional layer is initially formed on the semiconductor substrate 100 and then transferred to the diamond substrate 200. It has a large size and extremely high film quality, which is conducive to improving the performance of the terahertz device and reducing the manufacturing cost. The bonding method of the semiconductor substrate 100 and the diamond substrate 200 can be direct wafer bonding (Direct-wafer bonding), and LT-GeC on diamond (LT-GeC on Diamond, LT-GeCOD) is obtained, which is intended to improve the performance of the terahertz photoconductive antenna.

[0055] When the germanium carbon functional layer only includes the germanium carbon layer 131, the semiconductor substrate 100 is turned over to refer to Figure 5 As shown, the structure after bonding is referenced Figure 6When the germanium-carbon functional layer includes a composite structure layer 132, the semiconductor substrate 100 is flipped over with reference to Figure 7 As shown, the structure after bonding is referenced Figure 8 shown.

[0056] S104, removing the semiconductor substrate 100, referring to Figure 9-12 shown.

[0057] After the semiconductor substrate 100 and the diamond substrate 200 are bonded, the semiconductor substrate 100 can be removed to form germanium carbon on diamond. When a buffer layer 110 / 120 is formed between the semiconductor substrate 100 and the germanium carbon functional layer, the buffer layer can also be removed. The removal of the semiconductor substrate 100 and the buffer layer can be achieved by thinning the film layer, and the thinning method includes grinding, dry etching and chemical mechanical polishing (CMP), etc. For example, the semiconductor substrate 100 can be removed by mechanical thinning, the buffer layer can be removed by dry etching, and the germanium carbon functional layer can also be thinned to reach the target thickness. After removing the semiconductor substrate 100, the germanium carbon functional layer is exposed, and the thickness of the retained germanium carbon functional layer ranges from 100 to 3000nm.

[0058] When the germanium carbon functional layer only includes the germanium carbon layer 131, the structure after removing the semiconductor substrate 100 is as shown in FIG. Fig. 9 As shown, the structure after removing the buffer layer is referenced Fig.10 When the germanium-carbon functional layer includes a composite structure layer 132, the structure after removing the semiconductor substrate 100 is referenced Fig.11 As shown, the structure after removing the buffer layer is referenced Fig.12 shown.

[0059] S105, forming an electrode on the germanium carbon functional layer, referring to Fig.13 and Fig.14 shown.

[0060] After the thickness of the germanium carbon functional layer is exposed, an electrode may be formed on the germanium carbon functional layer, the electrode including a positive electrode 220 and a negative electrode 230, and the electrode may be a Schottky electrode. During the use of the terahertz photoconductive antenna, the electrode may provide a driving signal to the germanium carbon functional layer to emit a terahertz signal, or the electrode may obtain a current signal generated by the germanium carbon functional layer absorbing the terahertz signal.

[0061] When the germanium carbon functional layer only includes the germanium carbon layer 131, the structure after forming the electrode is referred to as Fig.13 When the germanium-carbon functional layer includes a composite structure layer 132, the structure after forming the electrode is referenced Fig.14 shown.

[0062] The manufacturing method of the above-mentioned terahertz photoconductive antenna is conducive to improving the performance of the terahertz photoconductive antenna and reducing the manufacturing cost. It is conducive to the rapid development of LT-GeC terahertz photoconductive antenna in security inspection, anti-terrorism, biomedicine, atmospheric remote sensing, space astronomy, satellite observation and military, and has great research significance and economic benefits.

[0063] The present application provides a method for manufacturing a terahertz photoconductive antenna, which comprises sequentially forming a germanium-carbon functional layer and a first bonding layer on a semiconductor substrate, providing a diamond substrate, on which a second bonding layer is formed, flipping the semiconductor substrate so that the first bonding layer faces the second bonding layer, bonding the semiconductor substrate and the diamond substrate, removing the semiconductor substrate, and forming an electrode on the germanium-carbon functional layer, thereby realizing the manufacture of the terahertz photoconductive antenna. Since the substrate of the formed terahertz photoconductive antenna is a diamond substrate, the heat generated in the device can be quickly conducted to the heat dissipation system, thereby effectively reducing the overall temperature of the terahertz device and reducing the risk of thermal breakdown of the terahertz device. In addition, the germanium-carbon functional layer enables the terahertz device to have advantages such as higher carrier mobility, wider band gap, better thermal conductivity, and stronger radiation resistance. The germanium-carbon functional layer is initially formed on the semiconductor substrate and then transferred to the diamond substrate. It has a large size and extremely high film quality, which is conducive to improving the performance of the terahertz device and reducing the manufacturing cost.

[0064] Based on the manufacturing method of a terahertz photoconductive antenna provided in the above embodiment, the embodiment of the present application further provides a terahertz photoconductive antenna, referring to Fig.14 As shown, the terahertz photoconductive antenna includes:

[0065] Diamond substrate;

[0066] A second bonding layer, a first bonding layer and a germanium-carbon functional layer sequentially stacked on the diamond substrate;

[0067] The electrode on the germanium carbon functional layer.

[0068] Optionally, the germanium-carbon functional layer includes a germanium-carbon layer, a quantum well structure layer including a germanium-carbon layer, or a superlattice structure layer including a germanium-carbon layer.

[0069] Optionally, the carbon content in the germanium-carbon functional layer does not exceed 5%.

[0070] Optionally, the quantum well structure layer or superlattice structure layer includes alternately stacked barrier layers and potential well layers, the germanium carbon layer serves as the barrier layer, and the material of the potential well layer includes germanium tin, silicon germanium tin, silicon germanium or germanium.

[0071] Optionally, the thickness of the germanium-carbon functional layer is in the range of 100-3000 nm;

[0072] The thickness of the barrier layer in the quantum well structure is ≥10nm, the thickness of the potential well layer is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

[0073] Optionally, the material of the first bonding layer and the second bonding layer is amorphous silicon.

[0074] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the structural embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. Ordinary technicians in this field can understand and implement it without paying creative work.

[0075] The above is only a preferred implementation of the present application. Although the present application has been disclosed as a preferred embodiment, it is not intended to limit the present application. Any technician familiar with the art can use the above disclosed methods and technical contents to make many possible changes and modifications to the technical solution of the present application without departing from the scope of the technical solution of the present application, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still falls within the scope of protection of the technical solution of the present application.

Claims

1. A method for manufacturing a terahertz photoconductive antenna, characterized in that: include: forming a germanium-carbon functional layer and a first bonding layer in sequence on a semiconductor substrate; providing a diamond substrate, on which a second bonding layer is formed; Turning over the semiconductor substrate so that the first bonding layer faces the second bonding layer, and bonding the semiconductor substrate to the diamond substrate; removing the semiconductor substrate; An electrode is formed on the germanium carbon functional layer.

2. The method according to claim 1, characterized in that The germanium-carbon functional layer includes a germanium-carbon layer, a quantum well structure layer including a germanium-carbon layer, or a superlattice structure layer including a germanium-carbon layer.

3. The method according to claim 2, characterized in that The carbon content in the germanium-carbon functional layer does not exceed 5%.

4. The method according to claim 2, characterized in that: The quantum well structure layer or superlattice structure layer includes alternately stacked barrier layers and potential well layers, the germanium carbon layer serves as the barrier layer, and the material of the potential well layer includes germanium tin, silicon germanium tin, silicon germanium or germanium.

5. The method according to claim 4, characterized in that The thickness of the germanium carbon functional layer is in the range of 100-3000nm; The thickness of the barrier layer in the quantum well structure is ≥10nm, the thickness of the potential well layer is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

6. The method according to any one of claims 1 to 5, characterized in that: The material of the semiconductor substrate includes silicon, germanium or germanium carbon; When the material of the semiconductor substrate includes silicon, before forming the germanium-carbon functional layer on the semiconductor substrate, the method further includes: forming a buffer layer on the semiconductor substrate, wherein the material of the buffer layer includes a low-temperature germanium buffer layer and a high-temperature germanium buffer layer; The removing of the semiconductor substrate includes: removing the semiconductor substrate and the buffer layer.

7. The method according to any one of claims 1 to 5, characterized in that: The material of the first bonding layer and the second bonding layer is amorphous silicon.

8. A terahertz photoconductive antenna, characterized in that: include: Diamond substrate; A second bonding layer, a first bonding layer and a germanium-carbon functional layer sequentially stacked on the diamond substrate; The electrode on the germanium carbon functional layer.

9. The terahertz photoconductive antenna according to claim 8, characterized in that: The germanium-carbon functional layer includes a germanium-carbon layer, a quantum well structure layer including a germanium-carbon layer, or a superlattice structure layer including a germanium-carbon layer.

10. The method according to claim 9, characterized in that The carbon content in the germanium-carbon functional layer does not exceed 5%.

11. The terahertz photoconductive antenna according to claim 9, characterized in that: The quantum well structure layer or superlattice structure layer includes a barrier layer and a potential well layer. The germanium carbon layer serves as the barrier layer. The material of the potential well layer includes germanium tin, silicon germanium tin, silicon germanium or germanium.

12. The terahertz photoconductive antenna according to claim 11, characterized in that: The thickness of the germanium carbon functional layer is in the range of 100-3000nm; The thickness of the barrier layer in the quantum well structure is ≥10nm, the thickness of the potential well layer is in the range of 5-30nm, and the quantum well period is in the range of 10-300; the thickness of the barrier layer in the superlattice structure layer is in the range of 3-10nm, the thickness of the potential well layer is in the range of 5-30nm, and the superlattice period is in the range of 60-400.

13. The terahertz photoconductive antenna according to any one of claims 8 to 12, characterized in that: The material of the first bonding layer and the second bonding layer is amorphous silicon.

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