Wide bandgap semiconductor extreme ultraviolet detector with composite film layer structure

Abstract

The invention provides a wide bandgap semiconductor extreme ultraviolet detector with a composite film layer structure, and belongs to the technical field of semiconductor ultraviolet photoelectric detectors. Comprising an ohmic contact electrode, a wide bandgap semiconductor substrate layer, an n-type 4H-SiC heavily-doped layer and a low-doped 4H-SiC photon absorption layer which are arranged from bottom to top, and the low-doped 4H-SiC photon absorption layer is provided with a Schottky composite film layer and a passivation layer arranged on the periphery of the Schottky composite film layer. A metal bonding pad is arranged above the joint of the Schottky composite film layer and the passivation layer, and the Schottky composite film layer comprises a Mo metal layer arranged above the lightly doped 4H-SiC photon absorption layer and a Ru metal layer arranged above the Mo metal layer. The coordination difficulty between responsivity and reliability in the existing extreme ultraviolet detector preparation technology can be solved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor ultraviolet photodetector technology, and particularly to a wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure. Background Technology

[0002] Extreme ultraviolet (EUV) light generally refers to electromagnetic radiation with wavelengths between 121 nm and 10 nm in the electromagnetic spectrum, corresponding to photon energies of approximately 10.25 eV to 124 eV. This band lies between ultraviolet and soft X-rays, characterized by high photon energy, weak penetrating power, and easy absorption by matter. It has key applications in cutting-edge technologies such as photoelectron spectroscopy, solar physics imaging, plasma diagnostics, and EUV lithography. In particular, EUV lithography technology has become a core manufacturing method for semiconductor integrated circuits moving towards 14nm, 7nm, 5nm, and more advanced process nodes. Its core system includes a 13.5nm EUV light source and a matching EUV detector. Wide-bandgap semiconductors, represented by silicon carbide (SiC) and group III nitrides (such as GaN), are third-generation semiconductor materials that have attracted much attention in recent years. They possess outstanding advantages such as large bandgap (SiC approximately 3.26 eV, GaN approximately 3.4 eV), high thermal conductivity, high breakdown electric field, strong radiation resistance, and excellent chemical stability. These intrinsic properties make it promising not only for high-temperature, high-frequency, and high-power electronic devices, but also provide an ideal material platform for the development of high-performance ultraviolet (UV) and extreme ultraviolet (EUV) photodetectors. Its wide bandgap means that the intrinsic absorption edge is located in the ultraviolet band, making it naturally "blind" to visible and infrared light, which helps reduce background noise; while its high radiation resistance ensures that the device remains stable under high-energy photon irradiation, which is crucial for EUV detection applications.

[0003] Currently, commercial ultraviolet (UV) detectors based on SiC and GaN are relatively mature, with their response bands mainly covering the UV region from 200nm to 400nm. The device structures are mostly based on PIN diodes and Schottky barrier diodes. Research has also begun in the shorter EUV band (especially 13.5nm), and most EUV detectors currently being developed employ Schottky structures. A key technical challenge lies in the selection and fabrication of the Schottky metal electrode. Existing technologies often use high work function metals such as nickel (Ni) and platinum (Pt) to form a sufficient barrier height. However, these metals have extremely high extinction coefficients at a wavelength of 13.5nm, meaning that EUV light penetrates very shallowly within them (typically only a few nanometers). To ensure that a sufficient proportion of incident photons can penetrate the metal layer and be effectively collected by the underlying semiconductor absorption region, thereby obtaining considerable quantum efficiency and responsivity, the thickness of the metal electrode must be strictly controlled to be very thin (typically below 10nm).

[0004] However, the ultrathin metal electrode layer introduces significant reliability risks in practical applications. In high-intensity, long-duration scenarios such as EUV lithography machines, the detector will continuously endure high doses of 13.5nm photon irradiation. Under high-energy photon bombardment, the ultrathin metal film may experience problems such as atomic migration, interface reactions, pinhole formation, or even localized ablation, leading to electrode structure degradation, alteration of Schottky barrier characteristics, and ultimately, detector performance degradation or failure. This results in the current Schottky-type wide-bandgap semiconductor extreme ultraviolet detectors facing technical risks of insufficient reliability. Summary of the Invention

[0005] This invention provides a wide-bandgap semiconductor extreme ultraviolet (EUV) detector with a composite film structure. It addresses the challenge of balancing responsivity and reliability in existing EUV detector fabrication techniques. The technical solution is as follows: This invention provides a wide bandgap semiconductor extreme ultraviolet detector with a composite film structure, comprising, from bottom to top, an ohmic contact electrode, a wide bandgap semiconductor substrate, an n-type 4H-SiC heavily doped layer, and a lightly doped 4H-SiC photon absorption layer. A Schottky composite film and a passivation layer are disposed on the lightly doped 4H-SiC photon absorption layer. A metal pad is disposed above the junction of the Schottky composite film and the passivation layer. The Schottky composite film includes a Mo metal layer disposed above the lightly doped 4H-SiC photon absorption layer and a Ru metal layer disposed above the Mo metal layer.

[0006] Optionally, the thickness of the Mo metal layer ranges from 3 to 30 nm, and the thickness of the Ru metal layer ranges from 1 to 5 nm.

[0007] Optionally, the Schottky composite film further includes a Ni film layer, which is disposed below the Mo metal layer and in contact with the lightly doped 4H-SiC photon absorption layer.

[0008] Optionally, the thickness of the Ni film layer ranges from 0.5 to 2 nm.

[0009] Optionally, the wide bandgap semiconductor substrate is an n-type 4H-SiC substrate, and the thickness of the wide bandgap semiconductor substrate ranges from 200 to 600 μm.

[0010] Optionally, the thickness of the n-type 4H-SiC heavily doped layer ranges from 1 to 10 μm, and the doping concentration ranges from 5 × 10⁻⁶. 17 -2×10 19 cm -3 .

[0011] Optionally, the thickness of the lightly doped 4H-SiC photonic absorption layer ranges from 0.5 to 20 μm, and the doping concentration ranges from 1 × 10⁻⁶.13 -1×10 17 cm -3 .

[0012] Optionally, the ohmic contact electrode is a single-layer or multi-layer metal composite structure of Ti, Al, Ni, Au or Pt, and the thickness of the ohmic contact electrode ranges from 20 to 1000 nm.

[0013] Optionally, the metal pad is a single-layer or multi-layer metal composite structure of Ti, Al, Ni, Au or Pt, and the thickness of the metal pad ranges from 1 to 2 μm.

[0014] Optionally, the passivation layer is made of at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, or hafnium oxide.

[0015] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following: This invention relates to a wide-bandgap extreme ultraviolet (EUV) detector with a composite film structure. Addressing the conflict between responsivity improvement and reliability in existing Ni-Pt Schottky SiC-based wide-bandgap semiconductor EUV detectors, this invention employs a Schottky composite film layer on top of the device. Leveraging the high work function of Mo and its higher transmittance in the EUV band compared to metals like Ni and Pt, Mo is selected as the Schottky metal window material for the wide-bandgap semiconductor EUV detector, thereby improving its responsivity. Furthermore, a Ru metal layer is coated on the Mo surface as a protective film. Utilizing the relatively stable structure of Ru under high-energy EUV photon and secondary electron bombardment, the reliability of the wide-bandgap semiconductor EUV detector is ensured while simultaneously improving responsivity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the wide bandgap semiconductor extreme ultraviolet detector with composite film structure provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the wide bandgap semiconductor extreme ultraviolet detector with composite film structure provided in Embodiment 2 of the present invention; Figure 3 This is a physical image of a conventional Ni Schottky SiC extreme ultraviolet detector in the existing technology; Figure 4This is a physical image of the wide bandgap semiconductor extreme ultraviolet detector with a composite film structure provided in an embodiment of the present invention.

[0018] In the figure: 1-Ohmic contact electrode; 2-Wide bandgap semiconductor substrate; 3-n-type 4H-SiC heavily doped layer; 4-Low-doped 4H-SiC photon absorption layer; 5-Schottky composite film; 6-Passivation layer; 7-Metal pad; 51-Mo metal layer; 52-Ru metal layer; 53-Ni film. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0020] Figure 1 This is a schematic diagram of the wide bandgap semiconductor extreme ultraviolet detector with composite film structure provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram of the wide bandgap semiconductor extreme ultraviolet detector with composite film structure provided in Embodiment 2 of the present invention; Figure 3 This is a physical image of a conventional Ni Schottky SiC extreme ultraviolet detector in the existing technology; Figure 4 This is a physical image of the wide bandgap semiconductor extreme ultraviolet detector with a composite film structure provided in an embodiment of the present invention.

[0021] Example 1: like Figure 1 As shown, this embodiment of the invention provides a wide bandgap semiconductor extreme ultraviolet detector with a composite film structure. The device's layer structure, from bottom to top, includes: an ohmic contact electrode 1, a wide bandgap semiconductor substrate layer 2, an n-type 4H-SiC heavily doped layer 3, and a lightly doped 4H-SiC photon absorption layer 4. A Schottky composite film layer 5 and a passivation layer 6 are disposed on the periphery of the Schottky composite film layer 4. A metal pad 7 is disposed above the junction of the Schottky composite film layer 5 and the passivation layer 6. The Schottky composite film layer 5 includes a Mo metal layer 51 disposed above the lightly doped 4H-SiC photon absorption layer 4 and a Ru metal layer 52 disposed above the Mo metal layer 51.

[0022] In this embodiment of the invention, the ohmic contact electrode 1 is disposed on the back side of the wide bandgap semiconductor substrate 2, covering the entire n-type 4H-SiC substrate on the back side, with a thickness ranging from 20 to 1000 nm. This ohmic contact electrode 1 is used to establish good electrical contact with external circuits, extract the photoelectric signal from the detector, and serve as an electrical connection terminal during subsequent packaging and bonding processes.

[0023] In terms of material selection, the ohmic contact electrode 1 can be a single-layer or multi-layer metal composite structure made of Ti, Al, Ni, Au, or Pt. These metals have good conductivity and the ability to form ohmic contacts with SiC. In a preferred embodiment, Ni is used as the material for the ohmic contact electrode 1, with a thickness of 200 nm.

[0024] In terms of fabrication process, the ohmic contact electrode 1 is prepared by electron beam evaporation, with the deposition rate controlled at 0.5-2 nm / s. After preparation, rapid thermal annealing is required to form a good ohmic contact. In this embodiment, the annealing temperature is 800℃, carried out in a nitrogen atmosphere, and the annealing time is 1 minute. This annealing process promotes the reaction between the metal and SiC interface, forming a stable nickel silicide phase, reducing the contact resistance, and ensuring good ohmic contact characteristics.

[0025] The wide bandgap semiconductor substrate 2 is located above the ohmic contact electrode 1, serving as the mechanical support substrate and conductive substrate for the entire device. In this embodiment, the wide bandgap semiconductor substrate 2 is an n-type 4H-SiC substrate with a thickness ranging from 200 to 600 μm.

[0026] Specifically, the thickness of the wide bandgap semiconductor substrate 2 is 360 μm, and the doping concentration is 1 × 10⁻⁶. 19 cm -3 .

[0027] For material selection, 4H-SiC polytype was chosen as the substrate material. Compared with other SiC polytypes such as 6H-SiC and 3C-SiC, 4H-SiC has superior electrical properties, including higher electron mobility and better thermal conductivity. Its bandgap is approximately 3.26 eV, ensuring the device's natural blind-sensitivity to visible and infrared light, effectively reducing background noise.

[0028] The n-type 4H-SiC heavily doped layer 3 is located above the wide bandgap semiconductor substrate layer 2 and is prepared by epitaxial growth. Its thickness ranges from 1 to 10 μm, and the doping concentration is between 5 × 10⁻⁶. 17 -2×10 19 cm -3 In the preferred embodiment, the thickness of the n-type 4H-SiC heavily doped layer 3 is 5 μm, and the nitrogen doping concentration is 5 × 10⁻⁶. 18 cm -3 .

[0029] In terms of fabrication process, the n-type 4H-SiC heavily doped layer 3 was prepared by chemical vapor deposition (CVD) epitaxial growth technology. The doping concentration was controlled by precisely regulating the nitrogen flow rate.

[0030] The heavily doped n-type 4H-SiC layer 3 plays multiple key roles in the device. First, this layer effectively blocks the extension of substrate defects into the epitaxial layer, reducing the dislocation density of the epitaxial layer and improving material quality. Second, the heavily doped layer can alleviate lattice mismatch stress between the epitaxial layer and the substrate, improving interface quality and reducing interface state density. Third, the high doping characteristics of this layer help reduce the contact resistance between the device and the substrate, decrease series resistance, and improve the electrical performance of the device. In this embodiment, by introducing a 5 μm thick heavily doped layer, the dislocation density of the epitaxial layer and the series resistance of the device are reduced.

[0031] The lightly doped 4H-SiC photon absorption layer 4, located above the heavily doped n-type 4H-SiC layer 3, is the core functional layer of the device and the main absorption region for extreme ultraviolet photons, as well as the region for the generation and collection of photogenerated carriers. Its thickness ranges from 0.5 to 20 μm, and the doping concentration is between 1 × 10⁻⁶. 13 -1×10 17 cm -3 In a preferred embodiment, the thickness of the low-doped 4H-SiC photon absorption layer 4 is 3 μm, and the nitrogen doping concentration is 1 × 10⁻⁶. 14 cm -3 .

[0032] In terms of fabrication process, the low-doped 4H-SiC photon absorption layer 4 is also prepared by CVD epitaxial growth technology. The growth conditions are basically the same as those of the n-type 4H-SiC heavily doped layer 3, but the low doping concentration is precisely controlled by significantly reducing the nitrogen flow rate.

[0033] In terms of structural design, low doping is key to achieving high-performance detectors. Low doping concentration ensures that the layer has high resistivity, enabling the formation of a wide depletion region when the Schottky junction is reverse-biased. When 13.5 nm extreme ultraviolet photons penetrate the upper Schottky composite film layer 5, they are absorbed in the low-doped 4H-SiC photon absorption layer 4, exciting the generation of electron-hole pairs.

[0034] The optimized design of the low-doped 4H-SiC photon absorption layer 4 achieves multiple technical advantages. First, the low doping concentration of 1×10⁻⁶... 14 cm -3 This allows the depletion layer width to reach 2-3 μm at a relatively low reverse bias, covering the main light absorption region and improving the collection efficiency of photogenerated carriers. Secondly, the moderate layer thickness of 3 μm ensures sufficient absorption of extreme ultraviolet photons while avoiding the increased carrier transit time and dark current problems associated with excessive thickness, thus improving the device's response speed and signal-to-noise ratio. Thirdly, the low doping concentration reduces impurity scattering, increases carrier mobility, and lowers the recombination probability.

[0035] The Schottky composite film layer 5 is the core innovative structure of this invention. It is disposed on the surface of the lightly doped 4H-SiC photon absorption layer 4, fully covering the photosensitive area of ​​the device. This composite film layer adopts a two-layer structure design of Mo metal layer 51 and Ru metal layer 52. The two metal layers are deposited in situ to form a tightly bonded composite interface.

[0036] The Mo metal layer 51 is located below the Schottky composite film layer 5 and is in direct contact with the lightly doped 4H-SiC photon absorption layer 4 to form a Schottky barrier junction. Its thickness ranges from 3 to 30 nm, and in a preferred embodiment, the thickness of the Mo metal layer 51 is 10 nm.

[0037] In terms of material selection, Mo metal was chosen as the Schottky contact material for several advantages. First, Mo has a high work function of approximately 4.6 eV, and when in contact with 4H-SiC (electron affinity of approximately 3.7 eV), it can form a Schottky barrier height of approximately 0.9 eV. This barrier height is sufficient to effectively block thermally excited electrons and reduce the dark current of the device, while not being too high to hinder the injection of photogenerated carriers. Second, and crucially, Mo exhibits excellent optical transmittance characteristics at a wavelength of 13.5 nm. Its extinction coefficient is significantly lower than that of traditional metals such as Ni and Pt, allowing a 10 nm thick Mo layer to achieve a transmittance of 20-25% at a wavelength of 13.5 nm, while the transmittance of a Ni layer of the same thickness is only about 5-8%.

[0038] In terms of thickness optimization, 10nm is the optimal thickness after comprehensively considering optical transmittance, electrical properties, and mechanical stability. If the Mo layer is too thin, such as <5nm, although the optical transmittance is further improved, the film continuity deteriorates, making it prone to pinhole formation, leading to increased leakage current, while mechanical stability and radiation resistance decrease. If the Mo layer is too thick, such as >20nm, the optical transmittance is significantly reduced, affecting the detector responsivity.

[0039] The optimized design of the Mo metal layer 51 achieves a synergy between Schottky barrier formation and high optical transmittance. The 10nm thick Mo layer ensures good Schottky contact characteristics while allowing approximately 20-25% of incident 13.5nm photons to penetrate and reach the underlying SiC absorption layer, resulting in a 2-3 times improvement in responsivity compared to the traditional Ni Schottky structure.

[0040] The Ru metal layer 52 is located on top of the Schottky composite film layer 5, covering the surface of the Mo metal layer 51, and plays a key role as a protective layer. Its thickness ranges from 1 to 5 nm, and in a preferred embodiment, the thickness of the Ru metal layer 52 is 2 nm.

[0041] In terms of material selection, Ru metal was chosen as the protective layer material due to its unique advantages. Ru is a platinum group metal with extremely high chemical stability and oxidation resistance, remaining stable in both atmospheric and high-energy irradiation environments. More importantly, Ru exhibits excellent radiation resistance under high-energy 92 eV extreme ultraviolet photon bombardment and accompanying secondary electron bombardment. Its crystal structure is not prone to degradation or phase transition under long-term irradiation, effectively preventing oxidation, atomic migration, or ablation of the underlying Mo layer. Simultaneously, the 2 nm thick ultrathin Ru layer absorbs less 13.5 nm extreme ultraviolet light, without significantly reducing the overall transmittance.

[0042] In structural design, the choice of Ru layer thickness is crucial. A thickness of 2 nm is sufficient to form a continuous protective film, effectively isolating atmospheric oxygen and water vapor and preventing the Mo layer from oxidizing. If the Ru layer is too thin (<1 nm), it is difficult to form a continuous film, resulting in poor protection; if it is too thick (>5 nm), it will significantly increase light absorption and reduce detector responsivity.

[0043] Technical Effects: The Ru metal layer 52 significantly improves the reliability and long-term stability of the detector. Comparative experiments show that in the Mo / Ru composite detector with a Ru protective layer, the Ru metal layer 52 effectively prevents oxidation and radiation damage to the Mo metal layer 51, ensuring the stability of the Schottky barrier. Simultaneously, the high chemical stability of Ru facilitates long-term storage and use of the device.

[0044] Passivation layer 6 is disposed in the peripheral region of Schottky composite film layer 5, covering the edge and sidewalls of the device, and its thickness ranges from 50 to 1000 nm. The main function of passivation layer 6 is to protect the device surface, reduce surface leakage current, and improve the electrical performance and stability of the device.

[0045] Metal pads 7 are disposed above the junction of the Schottky composite film layer 5 and the passivation layer 6, with a thickness ranging from 1 to 2 μm. The main function of metal pads 7 is to provide a reliable soldering interface for subsequent packaging and wire bonding, and to lead the electrical signals of the detector to external circuitry.

[0046] In terms of material selection, the metal pad 7 can be a single-layer or multi-layer metal composite structure of Ti, Al, Ni, Au, or Pt. In the preferred embodiment, a Ti / Au dual-layer structure is adopted, with a Ti layer thickness of 50 nm and an Au layer thickness of 1000 nm, for a total thickness of approximately 1.05 μm. The Ti layer serves as an adhesion layer, forming a good interface bond with the underlying Ru metal layer 52 and passivation layer 6; the Au layer serves as the host layer, providing good conductivity and oxidation resistance, and offering an ideal welding surface for wire bonding, ensuring the complete transmission of detector signals and the long-term stable operation of the device.

[0047] Example 2: like Figure 2 As shown, this embodiment provides another wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure. Its overall structure is basically the same as that of Embodiment 1, with the main difference being the structure of the Schottky composite film 5. In this embodiment, the Schottky composite film 5 includes a three-layer metal structure: the bottom layer is a Ni film 53, the middle layer is a Mo metal layer 51, and the top layer is a Ru metal layer 52, forming a Ni / Mo / Ru three-layer composite structure.

[0048] Except for the Schottky composite film layer 5, the structures of the remaining layers, including the ohmic contact electrode 1, the wide bandgap semiconductor substrate layer 2, the n-type 4H-SiC heavily doped layer 3, the lightly doped 4H-SiC photon absorption layer 4, the passivation layer 6, and the metal pad 7, are completely identical to those in Example 1, and will not be described again here. The following focuses on describing the special structure of the Schottky composite film layer 5 in this example: The Ni film layer 53 is located at the bottom of the Schottky composite film layer 5, below the Mo metal layer 51, and is in direct contact with the lightly doped 4H-SiC photon absorption layer 4. Its thickness ranges from 0.5 to 2 nm, and in a preferred embodiment, the thickness of the Ni film layer 53 is 1 nm.

[0049] In terms of material selection, Ni was introduced as an ultrathin interface layer with special significance. Ni has a higher work function of approximately 5.0 eV, compared to Mo's approximately 4.6 eV, enabling it to form a higher Schottky barrier of approximately 1.3 eV with 4H-SiC. Although the higher barrier slightly increases the resistance to photogenerated carrier injection, it can more effectively suppress thermally excited electrons, significantly reduce dark current, and improve the detector's signal-to-noise ratio and detection sensitivity.

[0050] In terms of thickness design, the 1nm ultrathin Ni layer provides a higher energy barrier while exhibiting minimal absorption of 13.5nm extreme ultraviolet light with a transmittance of approximately 95%, thus not significantly reducing the overall optical transmittance. Simultaneously, the relatively weak radiation resistance of the 1nm ultrathin layer is effectively addressed thanks to the protection of the Mo layer.

[0051] After introducing a 1nm ultrathin Ni film layer, the dark current density of the device was further reduced to 10⁻¹⁰ A / cm². 2 The following is a reduction of approximately one order of magnitude compared to Example 1. The rectification ratio is increased to over 10⁶.

[0052] Table 1 compares the responsivity of the wide-bandgap semiconductor extreme ultraviolet (EUV) detector with the composite film structure provided in the two embodiments of the present invention with that of a conventional Ni Schottky SiC EUV detector at a wavelength of 13.5 nm. Referring to Table 1, in this embodiment, although the responsivity decreases slightly due to the increased barrier height, the signal-to-noise ratio is correspondingly improved, and the overall detection performance is optimized. This structure is particularly suitable for applications requiring extremely low dark current and high signal-to-noise ratio, such as weak light detection and precision optical measurement. Furthermore, its responsivity still far exceeds that of traditional conventional Ni Schottky SiC EUV detectors.

[0053] Table 1 In this embodiment, the Ni / Mo / Ru three-layer composite structure achieves triple optimization of barrier height, optical transmittance, and reliability: the Ni layer 53 provides a high barrier to reduce dark current, the Mo layer 51 provides high transmittance to ensure responsivity, and the Ru layer 52 provides radiation protection to ensure stability. The synergistic effect of the three layers allows the device to achieve a new balance between dark current, responsivity, and long-term stability. The Mo / Ru two-layer structure of Embodiment 1 or the Ni / Mo / Ru three-layer structure of Embodiment 2 can be flexibly selected according to different application requirements.

[0054] The wide bandgap extreme ultraviolet detector with composite film structure proposed in this invention is not limited to SiC-based Schottky extreme ultraviolet detectors, but is also applicable to wide bandgap semiconductor extreme ultraviolet detectors with a bandgap greater than 3.0 eV, including wide bandgap semiconductors such as GaN, GaO, and diamond.

[0055] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0056] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure, characterized in that, The structure includes, from bottom to top, an ohmic contact electrode (1), a wide bandgap semiconductor substrate layer (2), an n-type 4H-SiC heavily doped layer (3), and a lightly doped 4H-SiC photon absorption layer (4). A Schottky composite film layer (5) and a passivation layer (6) are disposed on the periphery of the Schottky composite film layer (5). A metal pad (7) is disposed above the connection between the Schottky composite film layer (5) and the passivation layer (6). The Schottky composite film layer (5) includes a Mo metal layer (51) disposed above the lightly doped 4H-SiC photon absorption layer (4) and a Ru metal layer (52) disposed above the Mo metal layer (51).

2. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to claim 1, characterized in that, The thickness of the Mo metal layer (51) ranges from 3 to 30 nm, and the thickness of the Ru metal layer (52) ranges from 1 to 5 nm.

3. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to claim 1, characterized in that, The Schottky composite film (5) also includes a Ni film (53), which is disposed below the Mo metal layer (51) and in contact with the low-doped 4H-SiC photon absorption layer (4).

4. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to claim 3, characterized in that, The thickness of the Ni film (53) ranges from 0.5 to 2 nm.

5. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to claim 1, characterized in that, The wide bandgap semiconductor substrate (2) is an n-type 4H-SiC substrate, and the thickness of the wide bandgap semiconductor substrate (2) ranges from 200 to 600 μm.

6. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to claim 1, characterized in that, The thickness of the n-type 4H-SiC heavily doped layer (3) ranges from 1 to 10 μm, and the doping concentration ranges from 5 × 10⁻⁶. 17 -2×10 19 cm -3 .

7. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to any one of claims 1 to 6, characterized in that, The thickness of the lightly doped 4H-SiC photonic absorption layer (4) ranges from 0.5 to 20 μm, and the doping concentration ranges from 1 × 10⁻⁶. 13 -1×10 17 cm -3 .

8. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to any one of claims 1 to 6, characterized in that, The ohmic contact electrode (1) is a single-layer or multi-layer metal composite structure of Ti, Al, Ni, Au or Pt, and the thickness of the ohmic contact electrode (1) ranges from 20 to 1000 nm.

9. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to any one of claims 1 to 6, characterized in that, The metal pad (7) is a single-layer or multi-layer metal composite structure of Ti, Al, Ni, Au or Pt, and the thickness of the metal pad (7) ranges from 1 to 2 μm.

10. The wide-bandgap semiconductor extreme ultraviolet detector with a composite film structure according to any one of claims 1 to 6, characterized in that, The passivation layer (6) is made of at least one of silicon dioxide, silicon nitride, aluminum nitride, aluminum oxide, or hafnium oxide.

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