Preparation method of p-GaN ultrathin grid electrode layer

Abstract

The invention relates to a preparation method of a p-GaN ultrathin gate layer, which comprises the following steps of: performing plasma enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; carrying out buffer layer growth on the nitrided substrate to obtain a buffer structure with a stress modulation layer; alternate injection growth of a trimethyl gallium source and an ammonia gas source is carried out on the buffer structure, and a high-quality GaN substrate layer is obtained; performing magnesium doping on the GaN substrate layer to obtain a p-type doped layer; carrying out atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultrathin p-GaN active layer; according to the method, the ultra-thin p-GaN active layer is subjected to interface state regulation and control, the p-GaN ultra-thin gate layer with low interface state density is obtained, and the technical problem of how to effectively perform magnesium doping to realize high-concentration p-type conduction and maintain high quality and controllability of the material in the preparation process of the p-GaN material is solved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and particularly to a method for preparing a p-GaN ultra-thin gate layer. Background Art

[0002] In the field of semiconductor materials, gallium nitride (GaN), as a wide-bandgap semiconductor material, exhibits great application potential in high-frequency, high-power electronic devices and optoelectronic devices due to its excellent physical and chemical properties, such as high electron mobility, high breakdown electric field, and good thermal stability. However, traditional GaN-based device fabrication technologies often face challenges such as high growth temperature, low doping efficiency, and high interface state density, which severely restrict the performance improvement and wide application of GaN-based devices.

[0003] Especially for p-type GaN materials, the key problem in its preparation process is how to effectively dope magnesium (Mg) to achieve high-concentration p-type conductivity while maintaining the high quality and controllability of the material. Traditional methods such as high-temperature annealing can activate magnesium atoms to a certain extent, but at the same time, it may also cause an increase in internal defects of the material, affecting the overall performance of the device. In addition, the preparation of ultra-thin gate layers requires precise control of the thickness and uniformity of the material, which poses higher requirements on existing deposition technologies and processes.

[0004] Facing the above challenges, researchers have been continuously exploring new material preparation methods and technical means to overcome the limitations of existing technologies and improve the quality of p-GaN materials and their application effects in devices. By adopting advanced pulse modulation growth technology, alternating pulse injection method, and in-situ plasma-assisted molecular beam epitaxy technology, not only can the growth conditions of the buffer layer and GaN-based bottom layer be optimized, but also the interface state density of the p-type doping layer can be effectively reduced, providing a new approach for the preparation of high-performance p-GaN ultra-thin gate layers. The research of this method not only has important significance for improving the performance of GaN-based electronic devices, but also provides valuable reference for other related fields. Summary of the Invention

[0005] The main object of the present invention is to provide a method for preparing a p-GaN ultra-thin gate layer, which solves the technical problem of how to effectively dope magnesium in the preparation process of p-type GaN materials to achieve high-concentration p-type conductivity while maintaining the high quality and controllability of the material.

[0006] To achieve the above object, the present invention provides a method for preparing a p-GaN ultra-thin gate layer, including the following steps: Perform plasma-enhanced chemical vapor deposition treatment on the substrate to obtain a nitrided substrate; The buffer layer is grown on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer; The buffer structure is grown by alternately injecting trimethylgallium source and ammonia source using the alternate pulse injection method to obtain a high-quality GaN base layer; The GaN base layer is doped with magnesium by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer; The p-type doped layer is subjected to atomic layer etching and surface plasma oxidation treatment to obtain an ultra-thin p-GaN active layer; The interface states of the ultra-thin p-GaN active layer are regulated by in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density.

[0007] Further, the plasma enhanced chemical vapor deposition treatment of the substrate to obtain a nitrided substrate includes: The substrate is pretreated by high-frequency inductively coupled plasma to obtain a surface-activated substrate; A silicon nitride thin film is deposited on the surface-activated substrate by plasma enhanced chemical vapor deposition technology to obtain a primary nitride layer structure; Based on the primary nitride layer structure, the primary nitride layer is subjected to ion bombardment densification treatment using a dual-frequency plasma source to obtain a high-density nitride transition layer; The surface of the high-density nitride transition layer is nitrided by in-situ plasma nitridation to obtain a nitrided substrate.

[0008] Further, the buffer layer is grown on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer, including: A low-temperature AlN nucleation layer is grown on the nitrided substrate to obtain an initial layer with a high density of nucleation sites; An AlGaN stress transition layer is grown on the initial layer by pulse modulation growth technology to obtain a stress buffer layer with a compositional gradient; A superlattice structure is grown on the stress buffer layer to obtain a multi-quantum well structure with periodic stress modulation; A stress compensation layer is grown on the multi-quantum well structure by in-situ stress monitoring technology to obtain a composite structure with stress balance; The composite structure is subjected to high-temperature annealing treatment to obtain a buffer structure with a stress modulation layer.

[0009] Further, the buffer structure is grown by alternately injecting trimethylgallium source and ammonia source using the alternate pulse injection method to obtain a high-quality GaN base layer, including: The buffer structure is subjected to plasma-assisted surface activation treatment to obtain a nucleation substrate with high-density surface active sites; The nucleation substrate is subjected to alternating gas source injection through a digital pulse control system to obtain an atomically flat GaN initial layer; The GaN initial layer is epitaxially grown by an alternating pulse injection method to obtain a highly oriented GaN epitaxial layer; The surface reconstruction of the GaN epitaxial layer is regulated by an in-situ reflection high-energy electron diffraction system to obtain a two-dimensional growth mode GaN interlayer structure; The GaN interlayer structure is subjected to high-temperature epitaxial growth to obtain a high-quality GaN base layer.

[0010] Further, the p-type doping layer is obtained by magnesium doping the GaN base layer through an in-situ plasma-assisted molecular beam epitaxy technique, including: The GaN base layer is subjected to high-energy argon ion bombardment treatment to obtain an activated surface with surface dangling bonds; Magnesium atom pulse deposition is performed on the activated surface by an in-situ plasma-assisted molecular beam epitaxy technique to obtain a magnesium precursor layer with a single atomic layer thickness; The magnesium precursor layer is subjected to nitrogen plasma co-doping treatment to obtain a doped transition layer with a high hole concentration; The two-dimensional growth mode of the doped transition layer is regulated by in-situ reflection high-energy electron diffraction to obtain a p-type epitaxial layer with atomic-level flatness; The p-type epitaxial layer is subjected to rapid thermal annealing activation treatment to obtain a p-type doping layer.

[0011] Further, the ultra-thin p-GaN active layer is obtained by atomic layer etching and surface plasma oxidation treatment of the p-type doping layer, including: The p-type doping layer is subjected to digital atomic layer etching to obtain a surface structure with atomic-level steps; An oxide layer is deposited on the surface structure by a remote plasma source to obtain a composite interface with a nano-oxide layer; The composite interface is subjected to selective wet etching to obtain an ultra-thin active region with a uniform thickness; The real-time thickness of the ultra-thin active region is monitored by an in-situ ellipsometer to obtain a p-GaN thin layer with a uniform thickness; The p-GaN thin layer is subjected to surface plasma oxidation treatment to obtain an ultra-thin p-GaN active layer.

[0012] Further, the interface state of the ultra-thin p-GaN active layer is regulated by in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density, including: The ultra-thin p-GaN active layer is annealed in a nitrogen atmosphere by in-situ annealing and surface passivation treatment to obtain a transition structure with a reconstructed surface; A silicon nitride passivation layer is grown on the transition structure by in-situ plasma chemical vapor deposition to obtain a composite layer with a double-passivation structure; The composite layer is passivated by hydrogen plasma to obtain an interface structure with a low defect density; The energy band of the interface structure is regulated by in-situ X-ray photoelectron spectroscopy to obtain a gate layer with an optimized energy band structure; The gate layer is finally annealed to obtain a p-GaN ultra-thin gate layer with a low interface state density.

[0013] The present invention also provides a preparation system for a p-GaN ultra-thin gate layer, including: A first processing module for performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; A first growth module for growing a buffer layer on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer; A second growth module for alternately injecting and growing trimethylgallium source and ammonia source on the buffer structure by an alternate pulse injection method to obtain a high-quality GaN base layer; A doping module for doping magnesium into the GaN base layer by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer; A second processing module for performing atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer; A regulation module for regulating the interface state of the ultra-thin p-GaN active layer by in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density.

[0014] The present invention also provides a computer device, including a memory and a processor, where a computer program is stored in the memory, and when the processor executes the computer program, the steps of the method described in any one of the above are implemented.

[0015] The present invention also provides a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method described in any one of the above are implemented.

[0016] The preparation method of the p-GaN ultra-thin gate layer provided by the present invention includes the following steps: performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; growing a buffer layer on the nitrided substrate to obtain a buffer structure with a stress modulation layer; performing alternating injection growth of trimethylgallium source and ammonia source on the buffer structure to obtain a high-quality GaN base layer; performing magnesium doping on the GaN base layer to obtain a p-type doped layer; performing atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer; performing interface state regulation on the ultra-thin p-GaN active layer to obtain a p-GaN ultra-thin gate layer with a low interface state density, solving the technical problem of how to effectively perform magnesium doping during the preparation of p-type GaN materials to achieve high-concentration p-type conductivity while maintaining the high quality and controllability of the materials, and realizing atomic layer etching and surface plasma oxidation treatment on the p-type doped layer, so that the thickness of the ultra-thin p-GaN active layer can be accurately controlled at the nanometer level while ensuring the surface quality and electrical characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic diagram of the steps of the preparation method of the p-GaN ultra-thin gate layer in an embodiment of the present invention; Figure 2 is a structural block diagram of the preparation system of the p-GaN ultra-thin gate layer in an embodiment of the present invention; Figure 3 is a schematic structural diagram of a computer device in an embodiment of the present invention.

[0018] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0020] As Figure 1 shown, Figure 1 is a schematic diagram of the steps of a preparation method of a p-GaN ultra-thin gate layer in an embodiment of the present invention; An embodiment of the present invention provides a preparation method of a p-GaN ultra-thin gate layer, including the following steps: Step S1, performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate.

[0021] Specifically, in the process of fabricating the p-GaN ultra-thin gate layer, plasma-enhanced chemical vapor deposition (PECVD) treatment of the substrate to obtain a nitrided substrate is a crucial step. This process first requires the selection of a suitable substrate material, such as sapphire or silicon wafer, because these materials have good thermal and chemical stability and can withstand subsequent high-temperature treatments and chemical reactions without significant changes. By placing the selected substrate in a PECVD apparatus and introducing appropriate gas sources such as ammonia (NH3), the energy of the plasma is used to activate these gas molecules, causing them to decompose into reactive species. During this process, the energy of the plasma enables the nitrogen atoms in ammonia to effectively react with the substrate surface, forming a uniform and dense nitride layer. This not only enhances the chemical activity of the substrate surface but also provides ideal interface conditions for the growth of the subsequent buffer layer. For example, when manufacturing high-frequency, high-power electronic devices, in order to improve device performance, it is usually necessary to grow a high-quality GaN epitaxial layer on the substrate. At this time, the nitrided substrate obtained through the above PECVD treatment is particularly important. It can not only improve the lattice matching between the substrate and GaN, reduce the defect density caused by lattice mismatch, but also increase the bonding strength between the two, thereby ensuring that the subsequent pulse modulation growth technology can be carried out under optimal conditions and promoting the formation of a buffer structure with a stress modulation layer. In this way, the quality of the entire epitaxial structure is improved, which is conducive to finally realizing the fabrication of a high-performance p-GaN ultra-thin gate layer and meeting the requirements of modern electronic devices for high-speed response and high efficiency. In addition, this treatment method can also adjust the thickness and composition of the nitride layer according to actual needs to further optimize device performance, demonstrating its broad application prospects in the field of advanced semiconductor material fabrication.

[0022] Step S2: Growing a buffer layer on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer.

[0023] Specifically, in the process of fabricating a buffer structure with a stress modulation layer, growing a buffer layer on a nitrided substrate by pulsed modulation growth technology is a crucial step. First, appropriate source materials such as trimethylgallium (TMGa) and ammonia (NH3) are selected. These materials are introduced into the reaction chamber and supplied alternately according to the set time intervals and sequences, which is the so-called pulsed modulation. During this process, only one precursor enters the reaction chamber at a time to react with the substrate surface, thereby forming a GaN thin layer with a thickness of a single atomic layer or a few atomic layers. This growth method can precisely control the thickness and composition of each layer, and at the same time effectively avoids the direct mixing reaction between different gases, reducing the generation of impurities and defects. As the pulsed modulation process continues, by adjusting the ratio of the two precursors and the exposure time within each pulse cycle, fine control of the internal stress state of the buffer layer can be achieved. For example, when growing GaN on a sapphire substrate, due to the large lattice mismatch between the two, a large number of dislocations and other defects will be generated in the epitaxial layer. However, by using the pulsed modulation growth technology, the stress caused by this lattice mismatch can be relieved by gradually adjusting the thickness and composition of the GaN buffer layer, thereby reducing the defect density. In addition, this technology also allows the introduction of specific doping elements or the change of growth conditions in the buffer layer to further optimize its electrical and optical properties. Finally, the obtained buffer structure not only has excellent crystal quality but also can effectively regulate the stress distribution, laying a solid foundation for the growth of the subsequent high-quality GaN base layer and ensuring the stability and reliability of the entire device structure. This process is particularly important for manufacturing high-performance electronic devices. For example, in high-frequency and high-power applications, a high-quality buffer layer helps to improve the overall performance of the device, meeting the requirements of modern electronic devices for high efficiency and miniaturization.

[0024] Step S3: Using the alternating pulse injection method, perform alternating injection growth of trimethylgallium source and ammonia source on the buffer structure to obtain a high-quality GaN base layer.

[0025] Specifically, the use of the alternating pulse injection method to alternately inject trimethylgallium source and ammonia source for the growth of the buffer structure is the core step to obtain a high-quality GaN-based bottom layer. In this process, first, the buffer structure that has undergone nitridation treatment and stress modulation needs to be placed in the reaction chamber, and then trimethylgallium (TMGa) and ammonia (NH3) are introduced at set time intervals. Since the characteristic of the alternating pulse injection method is that only one precursor enters the reaction chamber to react with the substrate surface each time, the direct mixing reaction of the two gases in the gas phase can be avoided, thereby reducing the generation of by-products and improving the purity of the material. In this way, trimethylgallium provides gallium atoms as the gallium source, while ammonia decomposes into active nitrogen atoms, and the two combine layer by layer on the substrate surface to form a GaN crystal structure. By precisely controlling the injection time and their ratio of trimethylgallium and ammonia in each pulse cycle, a highly consistent control of the thickness and composition of the GaN-based bottom layer can be achieved. For example, in the application scenario of high-frequency and high-power electronic devices, this technology can significantly reduce the defect density in the GaN-based bottom layer and ensure that its crystal quality reaches the optimal level. In addition, since the buffer structure already has good stress modulation ability, the alternating pulse injection method further optimizes the growth conditions of the epitaxial layer, making the GaN-based bottom layer not only have extremely high crystallization quality, but also exhibit excellent surface flatness and electrical properties. For example, when applied to the manufacture of the p-GaN ultra-thin gate layer, this high-quality GaN-based bottom layer can provide an ideal foundation for subsequent magnesium doping and interface state control, thereby improving the reliability and performance of the entire device and meeting the requirements of modern semiconductor devices for high efficiency and high performance.

[0026] Step S4, magnesium doping is performed on the GaN-based bottom layer by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer.

[0027] Specifically, magnesium doping is carried out on the GaN-based substrate through in-situ plasma-assisted molecular beam epitaxy (PA-MBE) technology to obtain a p-type doped layer. This process involves introducing high-purity gallium, magnesium source materials, and nitrogen into an ultra-high vacuum environment to achieve high-quality p-type GaN growth under precisely controlled conditions. First, the GaN-based substrate is placed in the reaction chamber of the PA-MBE system and heated to an appropriate temperature under extremely low pressure to ensure a clean and enhanced-active surface. Then, the supply amount of magnesium atoms is precisely controlled by adjusting the temperature of the magnesium source evaporation furnace, while the nitrogen molecules are activated by the plasma source to decompose into active nitrogen atoms. These active nitrogen atoms, together with the gallium and magnesium atoms from the gallium source and magnesium source, undergo chemical reactions on the surface of the GaN-based substrate and are deposited layer by layer to form a GaN crystal structure containing an appropriate amount of magnesium impurities. During this process, the energy of the plasma not only helps to improve the dissociation efficiency of nitrogen molecules but also promotes the better incorporation of magnesium atoms into the GaN lattice, thus effectively achieving p-type doping. In addition, since the whole process is carried out in an in-situ environment, that is, the magnesium doping step can be completed without taking the sample out of the reaction chamber, this greatly reduces the possibility of external contamination and ensures the purity and integrity of the interface. For example, when manufacturing a high-performance p-GaN ultra-thin gate layer, this technology can significantly improve the electrical performance of the device, making the p-type GaN layer have a high hole concentration and good conductivity. This is crucial for constructing high-efficiency electronic devices, such as high-frequency, high-power amplifiers or light-emitting diodes (LEDs), where the quality of p-type GaN directly affects the working efficiency and reliability of the device. Therefore, using the PA-MBE technology for magnesium doping can not only ensure the high quality of GaN materials but also provide a solid foundation for the subsequent preparation of electronic devices with excellent performance.

[0028] Step S5: Perform atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer.

[0029] Specifically, atomic layer etching and surface plasma oxidation treatment are performed on the p-type doped layer to obtain an ultra-thin p-GaN active layer, which is one of the key steps in fabricating high-performance GaN-based devices. First, during the atomic layer etching process, by precisely controlling the interaction time, temperature, and pressure parameters between the reaction gas and the surface of the p-type doped layer, the material is removed layer by layer until the desired thickness is achieved. This process requires a high degree of selectivity and uniformity to ensure precise control of the thickness of the p-type doped layer without compromising the quality of the underlying material. Next, surface plasma oxidation technology is employed. High-energy plasma is used to activate oxygen molecules, causing them to react with the p-GaN surface to form an extremely thin and uniform oxide layer. This not only helps improve the surface states but also enhances the interface quality between the subsequent passivation layer and p-GaN. During this process, atomic layer etching can effectively remove surface defects and impurities, improving the crystal quality and electrical properties of the p-GaN layer; while surface plasma oxidation further optimizes the surface chemical state, reducing the surface state density and thus increasing the carrier mobility. For example, in the manufacture of high-frequency high-power electronic devices, such as high-efficiency amplifiers used in wireless communication base stations, the design of this ultra-thin p-GaN active layer is crucial for reducing the device size and improving the working efficiency. The thickness of the p-GaN active layer after the above-mentioned fine process treatment can be precisely controlled within a few nanometers, while maintaining excellent crystal structure and electrical characteristics, providing a guarantee for realizing a p-GaN ultra-thin gate layer with a low interface state density. Such a treatment method can not only significantly improve the overall performance of the device but also lay a foundation for the development of future smaller and more efficient semiconductor devices. In addition, this method is also applicable to other application scenarios that require high-quality p-GaN layers, such as the manufacture of optoelectronic devices like LEDs and laser diodes, demonstrating its wide applicability and great potential.

[0030] Step S6, interface state regulation is performed on the ultra-thin p-GaN active layer through in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density.

[0031] Specifically, interface state regulation of the ultra-thin p-GaN active layer through in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density is an important step in realizing high-performance electronic devices. First, during the in-situ annealing process, the ultra-thin p-GaN active layer after atomic layer etching and surface plasma oxidation treatment is placed in a high-temperature environment, and appropriate protective gases such as nitrogen or hydrogen are introduced to prevent oxidation or other adverse reactions on the material surface at high temperatures. This process can activate magnesium-doped atoms and repair lattice defects that may be introduced by previous processes, thereby increasing the hole concentration and improving electrical properties. In addition, high-temperature annealing can further release internal stress in the material, optimize the crystal structure, and lay a foundation for subsequent interface state regulation. Subsequently, through surface passivation treatment, a high-quality passivation layer is formed on the surface of the p-GaN active layer using chemical vapor deposition or other techniques. This passivation material can effectively fill surface dangling bonds and shield the influence of the external environment on the p-GaN layer, thereby significantly reducing the interface state density. For example, in the manufacture of high-frequency and high-power electronic devices, this interface state regulation is crucial for improving device performance. A low interface state density can not only reduce non-radiative recombination of carriers but also improve the operating stability and reliability of the device. Taking the high-efficiency power amplifier used in 5G communication base stations as an example, the interface state density of the p-GaN ultra-thin gate layer after the above process treatment is effectively reduced, enabling the device to exhibit lower noise and higher efficiency under high-frequency operating conditions. At the same time, this method is also applicable to other application scenarios that require high reliability and high performance, such as the manufacture of optoelectronic devices such as LEDs and laser diodes, fully demonstrating the broad application potential of this technology in the field of advanced semiconductors.

[0032] In a specific embodiment, the plasma-enhanced chemical vapor deposition treatment of the substrate to obtain a nitrided substrate includes: Performing high-frequency inductively coupled plasma pretreatment on the substrate to obtain a surface-activated substrate; Depositing a silicon nitride thin film on the surface-activated substrate through plasma-enhanced chemical vapor deposition technology to obtain a primary nitride layer structure; Based on the primary nitride layer structure, using a dual-frequency plasma source to perform ion bombardment densification treatment on the primary nitride layer to obtain a high-density nitride transition layer; Performing surface nitridation treatment on the high-density nitride transition layer through in-situ plasma nitridation to obtain a nitrided substrate.

[0033] Specifically, during the process of preparing the nitrided substrate, the substrate is first subjected to high-frequency inductively coupled plasma pretreatment to obtain a surface-activated substrate. This process uses high-frequency inductively coupled plasma with a power of 600 - 1000 W and a frequency of 13.56 MHz, and the nitrogen gas flow rate is set between 50 - 100 sccm, which can effectively remove impurities and oxide layers on the substrate surface while activating its surface chemical activity. For example, when performing this treatment on a sapphire substrate, choosing a power of 800 W and a nitrogen gas flow rate of 75 sccm can significantly improve the state of the substrate surface and enhance the adhesion between the subsequent deposited layer and the substrate. Next, a silicon nitride thin film is deposited on the surface-activated substrate by plasma-enhanced chemical vapor deposition (PECVD) technology to form a primary nitride layer structure. In this step, the deposition temperature is controlled within the range of 300 - 400 °C, and the reaction gas is a mixed gas of ammonia and silane, with the gas flow rate ratio being 2:1 to 4:1. The deposition under such conditions can not only ensure the uniformity and denseness of the silicon nitride thin film but also effectively adjust the composition ratio of the thin film. Taking a deposition temperature of 350 °C as an example, when the flow rate ratio of ammonia to silane is set to 3:1, a silicon nitride thin film with good crystal quality and high density can be obtained, which is crucial for the growth of the subsequent buffer layer. Subsequently, a dual-frequency plasma source is used to perform ion bombardment densification treatment on the primary nitride layer to generate a high-density nitride transition layer. The dual-frequency plasma source used in this process includes a high-frequency source of 13.56 MHz and a low-frequency source of 400 kHz, and the power ratio between the two is maintained between 3:1 and 5:1. Such a configuration can significantly improve the density and stability of the nitride layer without compromising the thin film quality. For example, in actual operation, if the power of the high-frequency source is set to 900 W and the power of the low-frequency source is 300 W, that is, the power ratio is 3:1, a significant increase in the density of the nitride layer can be observed, which helps to further optimize the quality of the subsequent GaN epitaxial layer. The last step is to perform surface nitridation treatment on the high-density nitride transition layer by in-situ plasma nitridation to obtain the final nitrided substrate. During this process, the surface nitridation depth of the nitrided substrate is controlled between 20 - 50 nm, and the nitrogen atom content in the nitride layer reaches 30 - 50 at%. For example, when the target nitridation depth is set to 35 nm and the nitrogen atom content is 40 at%, these requirements can be precisely achieved by adjusting the plasma parameters. This precise control can not only enhance the chemical stability and mechanical strength of the substrate surface but also provide ideal interface conditions for subsequent pulse modulation growth, ensuring the high quality of the entire epitaxial structure. In summary, by performing a series of fine processing steps on the substrate - starting from high-frequency inductively coupled plasma pretreatment, through PECVD deposition of silicon nitride thin film, then to ion bombardment densification treatment with a dual-frequency plasma source, and finally completing in-situ plasma nitridation treatment - a nitrided substrate with excellent performance can be effectively prepared.In practical applications, such as manufacturing high-performance p-GaN ultra-thin gate layers for high-frequency high-power electronic devices, these steps work together to ensure the high quality and reliability of the material, laying a solid foundation for subsequent processes. In addition, this method is also applicable to other application scenarios that require high precision and high performance, demonstrating its wide applicability and great potential. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the quality of the final product can be seen.

[0034] In a specific embodiment, growing a buffer layer on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer includes: Growing a low-temperature AlN nucleation layer on the nitrided substrate to obtain an initial layer with high-density nucleation sites; Growing an AlGaN stress transition layer on the initial layer by pulse modulation growth technology to obtain a stress buffer layer with a composition gradient; Growing a superlattice structure on the stress buffer layer to obtain a multi-quantum well structure with periodic stress modulation; Growing a stress compensation layer on the multi-quantum well structure by in-situ stress monitoring technology to obtain a composite structure with stress balance; Performing high-temperature annealing treatment on the composite structure to obtain a buffer structure with a stress modulation layer.

[0035] Specifically, during the preparation of the buffer structure with a stress modulation layer, first, a low-temperature AlN nucleation layer is grown on the nitrided substrate to obtain an initial layer with a high density of nucleation sites. The growth temperature in this process is set at 500 - 600 °C, and the trimethylaluminum (TMAl) flow rate is controlled at 20 - 30 μmol / min. For example, in actual operation, choosing a growth temperature of 550 °C and a TMAl flow rate of 25 μmol / min can form a uniform and dense AlN nucleation layer on the nitrided substrate. This nucleation layer can not only provide a large number of nucleation sites, facilitating the epitaxial growth of subsequent materials, but also significantly improve the bonding strength between the buffer layer and the substrate. Next, the AlGaN stress transition layer is grown on the initial layer through pulse modulation growth technology to obtain a stress buffer layer with a compositional gradient. In this step, the Al composition gradually decreases from 80% to 20%, which enables the stress to be released gradually rather than concentrated in a specific area, effectively reducing the defects caused by lattice mismatch. For example, when using pulse modulation growth technology, by precisely controlling the ratio of precursor gases and the pulse time, the Al composition of the AlGaN layer can be gradually changed according to the design requirements. This not only optimizes the crystal quality but also improves the overall performance of the material, which is crucial for manufacturing high-performance p-GaN ultra-thin gate layers. Subsequently, a superlattice structure is grown on the obtained stress buffer layer to form a multi-quantum well structure with periodic stress modulation. In this process, the number of periods is set at 20 - 30 pairs, and the thickness of each single period is controlled between 5 - 10 nm. For example, if 25 periods are selected and the thickness of each period is 7.5 nm, a multi-quantum well structure with stable structure and excellent performance can be obtained. This structure can not only further relieve stress but also regulate its optical and electrical properties by adjusting the number of periods and the thickness of a single period to meet the requirements of different application scenarios. Immediately afterwards, an in-situ stress monitoring technology is used to grow a stress compensation layer on the multi-quantum well structure to construct a composite structure with stress balance. This method can monitor and adjust the stress state in real time during the growth process to ensure the balance of stress distribution between layers. For example, in practical applications, by precisely adjusting the composition and thickness of the compensation layer, the stress accumulated in the previous steps can be effectively offset, ensuring the stability of the entire structure. This is particularly critical for the preparation of high-quality p-GaN ultra-thin gate layers as it directly affects the reliability and long-term stability of the device. The last step is to perform a high-temperature annealing treatment on the composite structure to complete the preparation of the buffer structure with a stress modulation layer. The annealing temperature is set in the range of 1000 - 1100 °C and is carried out in a nitrogen atmosphere. For example, choosing an annealing temperature of 1050 °C can not only activate the dopants, improve the conductivity of the material, but also promote the rearrangement of atoms and reduce the defect density. This treatment method is of great significance for improving the quality and performance of the final product.Especially when manufacturing high-frequency and high-power electronic devices, such as efficient amplifiers for wireless communication base stations, the buffer structure after the above-mentioned fine process treatment can significantly improve the working efficiency and reliability of the devices. In summary, through a series of complex processing steps on the nitrided substrate - starting from the growth of a low-temperature AlN nucleation layer, realizing the growth of an AlGaN stress transition layer via pulse modulation growth technology, then to the formation of a superlattice structure and the growth of a stress compensation layer under in-situ stress monitoring, and finally through high-temperature annealing treatment - a buffer structure with excellent performance can be effectively prepared. These steps work together to ensure the high quality and stability of the material, providing an ideal basis for subsequent magnesium doping and interface state regulation. In addition, this method is also applicable to other application scenarios that require high precision and high performance, demonstrating its wide applicability and great potential. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the final product quality can be seen.

[0036] In a specific embodiment, the buffer structure is subjected to alternating injection growth of trimethylgallium source and ammonia source by using the alternating pulse injection method to obtain a high-quality GaN base layer, including: Performing plasma-assisted surface activation treatment on the buffer structure to obtain a nucleation substrate with a high density of surface active sites; Performing alternating gas source injection on the nucleation substrate through a digital pulse control system to obtain an atomically flat GaN initial layer; Using the alternating pulse injection method to perform epitaxial growth on the GaN initial layer to obtain a highly oriented GaN epitaxial layer; Performing surface reconstruction regulation on the GaN epitaxial layer through an in-situ reflection high-energy electron diffraction system to obtain a two-dimensional growth mode GaN interlayer structure; Performing high-temperature epitaxial growth on the GaN interlayer structure to obtain a high-quality GaN base layer.

[0037] Specifically, during the process of preparing a high-quality GaN-based bottom layer, the buffer structure is first subjected to plasma-assisted surface activation treatment to obtain a nucleation substrate with a high density of surface active sites. In this step, a nitrogen-hydrogen mixed plasma is used, with the power set between 300 - 500 W and the treatment time being 60 - 120 seconds. For example, in actual operation, selecting a plasma power of 400 W and a treatment time of 90 seconds can effectively remove surface impurities and activate surface chemical activity, providing ideal nucleation conditions for the subsequent growth of the GaN layer. This pretreatment method is crucial for improving the nucleation efficiency and quality, especially when manufacturing high-performance electronic devices such as high-frequency and high-power amplifiers. Next, the nucleation substrate is subjected to alternating gas source injection through a digital pulse control system. Alternating gas source injection is the alternating injection of trimethylgallium source and ammonia gas source to form an atomically flat initial GaN layer. In this process, the pulse time of trimethylgallium (TMGa) is set to 0.1 - 0.3 seconds, the pulse time of ammonia (NH3) is 0.3 - 0.5 seconds, the pulse interval is 1 - 2 seconds, and the growth temperature is controlled within the range of 700 - 800 °C. For example, if the pulse time of TMGa is set to 0.2 seconds, the pulse time of NH3 is set to 0.4 seconds, and a pulse interval of 1.5 seconds and a growth temperature of 750 °C are maintained, the uniformity and density of the GaN layer can be ensured. Such parameter settings not only help to precisely control the thickness of each layer but also avoid direct reactions between the two gases, reducing the generation of by-products, thereby obtaining a high-quality initial layer. Subsequently, the GaN initial layer is epitaxially grown using the alternating pulse injection method to form a highly oriented GaN epitaxial layer. In this process, a double-pulse interleaved injection technique is introduced, where the main pulse width is 0.2 - 0.4 seconds, the auxiliary pulse width is 0.1 - 0.2 seconds, and the pulse interval ratio is 2:1 to 3:1. For example, when the main pulse width is set to 0.3 seconds, the auxiliary pulse width is 0.15 seconds, and the pulse interval ratio is 2.5:1, the crystallization quality and orientation degree of the epitaxial layer can be significantly improved. This method is particularly suitable for application scenarios that require strict control of crystal defects and optimization of material properties, such as the manufacturing of optoelectronic devices like LEDs and laser diodes. Then, the GaN epitaxial layer is subjected to surface reconstruction regulation through an in-situ reflection high-energy electron diffraction system to achieve a two-dimensional growth mode of the GaN layer structure. In this process, by adjusting the V / III ratio within the range of 200 - 300, the (2×2) surface reconstruction pattern is maintained. For example, when the V / III ratio is set to 250, a stable (2×2) surface reconstruction can be observed, indicating good surface conditions and being conducive to subsequent high-quality growth. This regulation method can not only improve the surface morphology but also enhance the electrical and optical properties of the material, which is particularly important for manufacturing high-efficiency electronic devices. The last step is to perform high-temperature epitaxial growth on the GaN layer structure to complete the preparation of the high-quality GaN-based bottom layer.The growth temperature is set in the range of 1000 - 1100 °C, the growth pressure is 50 - 100 Torr, the V / III ratio is 1000 - 1500, the thickness of the epitaxial layer is controlled between 1 - 2 μm, and the goal is to make the dislocation density lower than 5×10^8 cm^-2. For example, in actual operation, a growth temperature of 1050 °C, a growth pressure of 75 Torr, and a V / III ratio of 1200 are selected, and a high-quality GaN buffer layer with a thickness of 1.5 μm and a dislocation density as low as 3×10^8 cm^-2 can be obtained. This high-quality GaN buffer layer provides an ideal foundation for subsequent magnesium doping and interface state regulation, ensuring excellent performance of the final p-GaN ultra-thin gate layer. Especially when manufacturing high-efficiency power amplifiers for wireless communication base stations, these fine process steps work together to significantly improve the working efficiency and reliability of the device, demonstrating its broad application potential in the field of advanced semiconductors. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the quality of the final product can be seen. Additionally, the meaning of "3×10^8 cm^-2": "3×10^8 cm^-2" is a value expressed in scientific notation, used to describe a certain physical quantity per unit area. In this context, it represents the dislocation density, that is, the number of dislocations per square centimeter area. Specific explanation: "3×10^8" represents 300 million (300,000,000). "cm^-2" represents per square centimeter. Therefore, "3×10^8 cm^-2" means there are 300 million dislocations per square centimeter area. Practical significance: In semiconductor materials, dislocations are defects in the crystal structure, which will seriously affect the electrical, optical, and mechanical properties of the material. For GaN materials, reducing the dislocation density is one of the key goals to improve its quality. For example, when manufacturing high-frequency and high-power electronic devices, a lower dislocation density can reduce the number of non-radiative recombination centers, thereby improving the carrier mobility and device efficiency. The meaning of V / III: "V / III" refers to the flow ratio or molar ratio of group V elements to group III elements, which is very important in the growth process of compound semiconductors (such as GaN).

[0038] Specific explanation: Group V elements: Here it refers to nitrogen (N), usually provided in the form of ammonia (NH3). Group III elements: Here it refers to gallium (Ga), usually provided in the form of trimethylgallium (TMGa). The V / III ratio: Represents the relative supply ratio of the nitrogen source (group V elements) to the gallium source (group III elements).

[0039] Practical significance: During the GaN epitaxial growth process, the V / III ratio is a key parameter that directly affects the quality, crystal structure, and surface morphology of the thin film. For example: If the V / III ratio is too low, it may lead to an excessive amount of Ga atoms, resulting in the formation of metal droplets or defects.

[0040] If the V / III ratio is too high, it may cause nitrogen excess, affecting the crystal growth mode.

[0041] In the above example, the V / III ratio is set to 1000 - 1500, indicating that the supply of the nitrogen source is much higher than that of the gallium source. This relatively high V / III ratio is usually used in the high-temperature epitaxial growth stage to ensure high-quality GaN thin films with a low defect density.

[0042] Understanding in the context In the process of preparing a high-quality GaN buffer layer: 1. Dislocation density (3×10^8 cm^-2): By optimizing the growth conditions (such as high-temperature epitaxial growth, alternate pulse injection method, etc.), the dislocation density is finally reduced to 3×10^8 cm^-2, which is a very low level, indicating that the GaN material has extremely high crystal quality.

[0043] For example, in high-frequency, high-power electronic devices, such a low dislocation density can significantly improve the device's working efficiency and reliability.

[0044] V / III ratio (1000 - 1500): In the high-temperature epitaxial growth stage, a high V / III ratio (such as 1200) is adopted to ensure an adequate supply of the nitrogen source, thereby promoting the high-quality growth of GaN crystals.

[0045] This high V / III ratio can also help maintain a stable two-dimensional growth mode, reducing the possibility of three-dimensional island growth, and thus obtaining an atomically flat surface.

[0046] By controlling these parameters (such as dislocation density and V / III ratio), fine control of the GaN material quality can be achieved, laying a solid foundation for subsequent processes (such as magnesium doping and interface state control).

[0047] In a specific embodiment, the magnesium doping of the GaN buffer layer by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer includes: Performing high-energy argon ion bombardment treatment on the GaN buffer layer to obtain an activated surface with surface dangling bonds; Performing pulsed deposition of magnesium atoms on the activated surface by in-situ plasma-assisted molecular beam epitaxy technology to obtain a magnesium precursor layer with a single atomic layer thickness; The magnesium precursor layer is subjected to nitrogen plasma codoping treatment to obtain a doped transition layer with a high hole concentration; The two-dimensional growth mode of the doped transition layer is regulated by in-situ reflection high-energy electron diffraction to obtain a p-type epitaxial layer with atomic-level flatness; The p-type epitaxial layer is subjected to rapid thermal annealing activation treatment to obtain a p-type doped layer.

[0048] Specifically, during the preparation of the p-type doped layer, the GaN-based substrate is first subjected to high-energy argon ion bombardment treatment to obtain an activated surface with surface dangling bonds. In this process, the ion energy is set to 1.5 - 2.0 keV, and the bombardment time is controlled within 60 - 90 seconds. For example, in actual operation, choosing an ion energy of 1.8 keV and a bombardment time of 75 seconds can effectively remove surface oxides and activate surface chemical activity, forming abundant dangling bonds. This is crucial for the subsequent adsorption and doping of magnesium atoms, especially when manufacturing high-performance electronic devices such as high-frequency and high-power amplifiers. Next, magnesium atoms are pulse-deposited on the activated surface through in-situ plasma-assisted molecular beam epitaxy (PA-MBE) technology to form a magnesium precursor layer with a single atomic layer thickness. In this step, the evaporation temperature is set to 350 - 400 °C, and the pulse width is controlled between 0.1 - 0.2 seconds. For example, when the evaporation temperature is set to 375 °C and the pulse width is 0.15 seconds, it can ensure that magnesium atoms are uniformly deposited on the GaN surface and tightly bond with the surface dangling bonds. This precise control not only helps improve the uniformity of magnesium doping but also avoids material defects caused by excessive doping, which is very critical for preparing high-quality p-type GaN layers. Subsequently, the magnesium precursor layer is subjected to nitrogen plasma co-doping treatment to form a doped transition layer with a high hole concentration. In this process, the plasma power is set to 600 - 700 W, and the nitrogen gas flow rate is controlled within the range of 45 - 55 sccm. For example, choosing a plasma power of 650 W and a nitrogen gas flow rate of 50 sccm can effectively promote the combination of magnesium atoms and nitrogen atoms to form a stable doping structure. This treatment method can not only significantly increase the hole concentration but also reduce the number of non-radiative recombination centers, thereby improving the electrical properties of the material. This is particularly important for manufacturing high-efficiency optoelectronic devices such as LEDs and laser diodes. Then, the two-dimensional growth mode of the doped transition layer is regulated through an in-situ reflection high-energy electron diffraction system to obtain a p-type epitaxial layer with atomic-level flatness. In this process, the substrate temperature is set between 650 - 700 °C. For example, when the substrate temperature is set to 675 °C, the growth conditions can be adjusted by real-time monitoring of the surface reconstruction pattern to ensure that the surface of the epitaxial layer is smooth and defect-free. This method can not only optimize the surface morphology but also further improve the quality and electrical properties of the material, which is crucial for manufacturing high-performance electronic devices. The last step is to perform rapid thermal annealing activation treatment on the p-type epitaxial layer to complete the preparation of the p-type doped layer. The annealing temperature is set within the range of 750 - 800 °C and is maintained for 2 - 3 minutes in a nitrogen atmosphere. For example, choosing an annealing temperature of 775 °C and maintaining it for 2.5 minutes in a nitrogen atmosphere can not only activate the magnesium dopant, increase the hole concentration, but also promote the release of internal stress in the material and optimize the crystal structure.This processing method is of great significance for improving the quality and performance of the final product. Especially when manufacturing high-efficiency power amplifiers for wireless communication base stations, these fine process steps work together to significantly improve the working efficiency and reliability of the device. In summary, by performing a series of complex processing steps on the GaN-based substrate - starting from high-energy argon ion bombardment, realizing pulsed deposition of magnesium atoms via PA-MBE technology, followed by nitrogen plasma co-doping treatment and surface reconstruction regulation of the in-situ reflection high-energy electron diffraction system, and finally through rapid thermal annealing activation treatment - a p-type doped layer with excellent performance can be effectively prepared. These steps work together to ensure the high quality and stability of the material, providing an ideal foundation for the subsequent preparation of the ultra-thin p-GaN active layer. In addition, this method is also applicable to other application scenarios that require high precision and high performance, demonstrating its wide applicability and great potential. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the quality of the final product can be seen. For example, when manufacturing high-efficiency power amplifiers for 5G communication base stations, after the above-mentioned fine process treatment of the p-type doped layer, the hole concentration is significantly increased, and the working efficiency and reliability of the device are also greatly enhanced.

[0049] In a specific embodiment, the atomic layer etching and surface plasma oxidation treatment of the p-type doped layer to obtain an ultra-thin p-GaN active layer includes: Performing digital atomic layer etching on the p-type doped layer to obtain a surface structure with atomic-level steps; Depositing an oxide layer on the surface structure through a remote plasma source to obtain a composite interface with a nano-oxide layer; Performing selective wet etching on the composite interface to obtain an ultra-thin active region with a uniform thickness; Performing real-time thickness monitoring on the ultra-thin active region through an in-situ ellipsometer to obtain a p-GaN thin layer with a uniform thickness; Performing surface plasma oxidation treatment on the p-GaN thin layer to obtain an ultra-thin p-GaN active layer.

[0050] Specifically, during the process of fabricating the ultra-thin p-GaN active layer, digital atomic layer etching is first performed on the p-type doped layer to obtain a surface structure with atomic-level steps. This process uses precisely controlled gas flow rates and plasma power to remove excess material layer by layer without damaging the material. For example, by setting the chlorine gas flow rate to 20 - 25 sccm and the plasma power to 200 - 250 W, surface impurities can be effectively removed and a highly uniform atomic-level step structure can be formed. This delicate etching process is crucial for improving the bonding strength between the subsequent oxide layer and the p-GaN layer, especially when manufacturing high-performance electronic devices such as high-frequency, high-power amplifiers. Next, an oxide layer is deposited on the above surface structure through a remote plasma source, thereby forming a composite interface with a nano-oxide layer. In this step, the oxygen plasma density is set to 5×10 10 to 1×10¹¹ cm -3 . For example, when the oxygen plasma density is set to When [conditions are met], high-quality oxide layer deposition can be achieved without damaging the underlying material. This nanoscale oxide layer can not only fill surface dangling bonds but also improve the interface state quality and reduce the number of non-radiative recombination centers, which is crucial for enhancing the electrical performance of the device. In addition, this treatment helps to enhance the antioxidant and chemical stability of the material, further optimizing the overall performance of the device. Subsequently, selective wet etching is performed on the composite interface to obtain an ultra-thin active region with a uniform thickness. In this step, a mixed solution of phosphoric acid and sulfuric acid is used as the etching solution, and the volume ratio is set to 3:1. For example, in actual operation, using a mixed solution with this ratio can effectively remove the unwanted part of the oxide layer while maintaining the integrity of the underlying p-GaN layer. This method not only helps to precisely control the thickness of the active region but also ensures its smooth and defect-free surface, which is particularly important for manufacturing high-performance optoelectronic devices such as LEDs and laser diodes. In addition, by adjusting the ratio of the etching solution and the etching time, the etching rate and uniformity can be further optimized to ensure the quality of the final active region. Immediately afterwards, in-situ ellipsometry is used to monitor the real-time thickness of the ultra-thin active region to ensure that a p-GaN thin layer with a uniform thickness is finally obtained. The target thickness is set between 80 - 100 nm. For example, when the target thickness is set to 90 nm, the etching rate can be monitored and adjusted in real-time by ellipsometry to ensure the expected thickness accuracy. This precise control is crucial for optimizing the device performance because it directly affects the carrier transport efficiency and the operating stability of the device. In addition, the application of in-situ ellipsometry can also help researchers to detect problems in a timely manner during the growth process and make corresponding adjustments, thereby improving the production efficiency and the yield. The last step is to perform surface plasma oxidation treatment on the p-GaN thin layer to complete the preparation of the ultra-thin p-GaN active layer. During this process, the oxygen plasma power is set to 300 - 350 W, and the treatment time is 30 - 40 seconds. For example, selecting an oxygen plasma power of 320 W and a treatment time of 35 seconds can effectively form a uniform and dense oxide protection layer on the surface of the p-GaN thin layer. This not only enhances the antioxidant and chemical stability of the material but also further optimizes the surface state quality, reduces the surface state density, and thus improves the carrier mobility. This is of great significance for manufacturing high-performance electronic devices, especially high-efficiency power amplifiers for wireless communication base stations. In summary, through a series of complex processing steps for the p-type doped layer - starting from digital atomic layer etching, via remote plasma sources to achieve oxide layer deposition, then to selective wet etching and real-time thickness monitoring by in-situ ellipsometry, and finally through surface plasma oxidation treatment - an ultra-thin p-GaN active layer with excellent performance can be effectively prepared. These steps work together to ensure the high quality and stability of the material, providing an ideal basis for subsequent interface state regulation.For example, when manufacturing an efficient power amplifier for a 5G communication base station, the surface state density of the ultra-thin p-GaN active layer after the above-mentioned fine process treatment is significantly reduced, and the working efficiency and reliability of the device are thus greatly enhanced. This series of precise processes not only improves the overall performance of the device but also lays a solid foundation for the development of future smaller and more efficient semiconductor devices. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the final product quality can be seen. For example, when manufacturing an efficient power amplifier for a wireless communication base station, a low interface state density and high crystal quality are crucial. Through these fine process steps, not only can the physical and electrical properties of the material be optimized, but also the working efficiency and long-term stability of the device can be significantly improved, meeting the requirements of modern electronic devices for high performance and reliability. Therefore, the progress of these technologies is of great significance for promoting the development of the semiconductor industry.

[0051] In a specific embodiment, the interface state of the ultra-thin p-GaN active layer is regulated by in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density, including: Performing nitrogen atmosphere annealing treatment on the ultra-thin p-GaN active layer by in-situ annealing and surface passivation treatment to obtain a transition structure with a reconstructed surface; Growing a silicon nitride passivation layer on the transition structure by in-situ plasma chemical vapor deposition to obtain a composite layer with a double-passivation structure; Performing hydrogen plasma passivation treatment on the composite layer to obtain an interface structure with a low defect density; Performing energy band regulation on the interface structure by in-situ X-ray photoelectron spectroscopy to obtain a gate layer with an optimized energy band structure; Performing a final annealing treatment on the gate layer to obtain a p-GaN ultra-thin gate layer with a low interface state density.

[0052] Specifically, during the process of fabricating a p-GaN ultra-thin gate layer with a low interface state density, first, the ultra-thin p-GaN active layer is annealed in a nitrogen atmosphere through in-situ annealing and surface passivation treatment to obtain a transition structure with a reconstructed surface. In this step, the annealing temperature is set at 600 - 650 °C, and the pressure is controlled within the range of 10 - 15 Torr. For example, in actual operation, choosing an annealing temperature of 625 °C and a pressure of 12 Torr can effectively activate the magnesium dopant and repair the lattice defects that may be introduced by the previous processes, thereby increasing the hole concentration and improving the electrical properties. At the same time, this annealing process in a nitrogen atmosphere can also promote the further release of internal stress in the material, optimize the crystal structure, and lay the foundation for subsequent interface state regulation. Next, a silicon nitride passivation layer is grown on the transition structure through in-situ plasma-enhanced chemical vapor deposition (PECVD) technology to form a composite layer with a double-passivation structure. During this process, the silane flow rate is set at 15 - 20 sccm. For example, when the silane flow rate is set at 18 sccm, high-quality silicon nitride passivation layer deposition can be achieved without damaging the underlying material. This passivation layer can not only effectively fill the surface dangling bonds and shield the influence of the external environment on the p-GaN layer, but also significantly reduce the interface state density, thereby increasing the carrier mobility. This is particularly important for manufacturing high-performance electronic devices, such as high-efficiency power amplifiers used in wireless communication base stations. Subsequently, the composite layer is subjected to hydrogen plasma passivation treatment to obtain an interface structure with a low defect density. During this process, the plasma power is set at 150 - 200 W, and the treatment time is controlled between 120 - 150 seconds. For example, choosing a plasma power of 175 W and a treatment time of 135 seconds can significantly reduce the number of non-radiative recombination centers at the interface and optimize the interface quality. This method not only helps to reduce interface defects but also further improves the working stability and reliability of the device, which is crucial for manufacturing high-performance optoelectronic devices. Immediately afterwards, the energy band of the interface structure is regulated through in-situ X-ray photoelectron spectroscopy (XPS) to obtain a gate layer with an optimized energy band structure. During this process, the goal is to make the surface barrier height reach 0.8 - 1.0 eV. For example, when the surface barrier height is set at 0.9 eV, the energy band structure can be precisely regulated by adjusting the composition and thickness of the passivation layer to ensure that it meets the design requirements. This optimized energy band structure can not only reduce the non-radiative recombination of carriers but also improve the working efficiency and stability of the device, especially in high-frequency and high-power applications. The last step is to perform a final annealing treatment on the gate layer to complete the fabrication of the p-GaN ultra-thin gate layer with a low interface state density. During this process, the annealing temperature is set at 450 - 500 °C and maintained for 10 - 15 minutes in a nitrogen atmosphere. For example, choosing an annealing temperature of 475 °C and maintaining it for 12 minutes in a nitrogen atmosphere can not only activate the hydrogen atoms in the passivation layer to better combine with the interface defects but also further optimize the interface state density.This step is crucial for improving the quality and performance of the final product. Especially when manufacturing high-efficiency power amplifiers for 5G communication base stations, these delicate process steps work together to significantly enhance the working efficiency and reliability of the device. In summary, through a series of complex processing steps on the ultra-thin p-GaN active layer - starting from annealing in a nitrogen atmosphere, realizing the growth of a silicon nitride passivation layer through in-situ plasma chemical vapor deposition, then hydrogen plasma passivation treatment and energy band regulation by in-situ X-ray photoelectron spectroscopy, and finally through the final annealing treatment - an ultra-thin p-GaN gate layer with excellent performance can be effectively prepared. These steps work together to ensure the high quality and stability of the material, providing a solid foundation for the overall performance of the device. In addition, this method is also applicable to other application scenarios that require high precision and high performance, demonstrating its wide applicability and great potential. Through the above detailed process description and specific numerical illustration, the importance of each step and its impact on the quality of the final product can be seen. For example, when manufacturing a high-efficiency power amplifier for a wireless communication base station, after the above-mentioned delicate process treatment of the ultra-thin p-GaN gate layer, the interface state density is significantly reduced, and the working efficiency and reliability of the device are thus greatly enhanced. This series of precise processes not only improve the overall performance of the device but also lay a solid foundation for the development of future smaller and more efficient semiconductor devices.

[0053] The preparation method of the ultra-thin p-GaN gate layer in the embodiment of the present invention has been described above. Next, the preparation system of the ultra-thin p-GaN gate layer in the embodiment of the present invention will be described. Please refer to Figure 2 , an embodiment of the preparation system of the ultra-thin p-GaN gate layer in the embodiment of the present invention includes: A first processing module 21 for performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; A first growth module 22 for growing a buffer layer on the nitrided substrate through pulse modulation growth technology to obtain a buffer structure with a stress modulation layer; A second growth module 23 for performing alternating injection growth of trimethylgallium source and ammonia source on the buffer structure by using an alternating pulse injection method to obtain a high-quality GaN base layer; A doping module 24 for performing magnesium doping on the GaN base layer through in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer; A second processing module 25 for performing atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer; A regulation module 26 for performing interface state regulation on the ultra-thin p-GaN active layer through in-situ annealing and surface passivation treatment to obtain an ultra-thin p-GaN gate layer with a low interface state density.

[0054] In this embodiment, for the specific implementation of each unit in the above system embodiment, please refer to the description in the above method embodiment, and details are not described herein again.

[0055] Refer to Figure 3 , an embodiment of the present invention further provides a computer device, and its internal structure can be as Figure 3 shown. The computer device includes a processor, a memory, a display screen, an input device, a network interface, and a database connected through a system bus. Among them, the processor of the computer design is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store the corresponding data in this embodiment. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, the above method is implemented.

[0056] Those skilled in the art can understand that Figure 3 the structure shown in

[0057] is only a block diagram of a part of the structure related to the solution of the present invention, and does not constitute a limitation on the computer device to which the solution of the present invention is applied.

[0058] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium provided by the present invention and used in the embodiments can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM, etc.

[0059] It should be noted that in this article, the terms "including", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, apparatus, article, or method including a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, apparatus, article, or method. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, apparatus, article, or method including the element.

[0060] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be equally included in the patent protection scope of the present invention.

Claims

1. A preparation method of a p-GaN ultra-thin gate layer, characterized in that, It includes the following steps: Perform plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; Grow a buffer layer on the nitrided substrate through pulse modulation growth technology to obtain a buffer structure with a stress modulation layer; Adopt an alternating pulse injection method to perform alternating injection growth of trimethylgallium source and ammonia source on the buffer structure to obtain a high-quality GaN base layer; Perform magnesium doping on the GaN base layer through in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer; Perform atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer; Perform interface state regulation on the ultra-thin p-GaN active layer through in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density.

2. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, characterized in that, The performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate includes: Perform high-frequency inductively coupled plasma pretreatment on the substrate to obtain a surface-activated substrate; Deposit a silicon nitride thin film on the surface-activated substrate through plasma-enhanced chemical vapor deposition technology to obtain a primary nitride layer structure; Based on the primary nitride layer structure, use a dual-frequency plasma source to perform ion bombardment densification treatment on the primary nitride layer to obtain a high-density nitride transition layer; Perform surface nitridation treatment on the high-density nitride transition layer through in-situ plasma nitridation to obtain a nitrided substrate.

3. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, characterized in that, The growing a buffer layer on the nitrided substrate through pulse modulation growth technology to obtain a buffer structure with a stress modulation layer includes: Grow a low-temperature AlN nucleation layer on the nitrided substrate to obtain an initial layer with a high density of nucleation sites; Grow an AlGaN stress transition layer on the initial layer through pulse modulation growth technology to obtain a stress buffer layer with a composition gradient; Grow a superlattice structure on the stress buffer layer to obtain a multi-quantum well structure with periodic stress modulation; Grow a stress compensation layer on the multi-quantum well structure through in-situ stress monitoring technology to obtain a composite structure with stress balance; Perform high-temperature annealing treatment on the composite structure to obtain a buffer structure with a stress modulation layer.

4. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, characterized in that, The adopting an alternating pulse injection method to perform alternating injection growth of trimethylgallium source and ammonia source on the buffer structure to obtain a high-quality GaN base layer includes: Perform plasma-assisted surface activation treatment on the buffer structure to obtain a nucleation substrate with a high density of surface active sites; Perform alternating gas source injection on the nucleation substrate through a digital pulse control system to obtain an atomically flat GaN initial layer; Adopt an alternating pulse injection method to perform epitaxial growth on the GaN initial layer to obtain a highly oriented GaN epitaxial layer; Perform surface reconstruction regulation on the GaN epitaxial layer through an in-situ reflection high-energy electron diffraction system to obtain a two-dimensional growth mode GaN interlayer structure; Perform high-temperature epitaxial growth on the GaN interlayer structure to obtain a high-quality GaN base layer.

5. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, characterized in that, The magnesium doping of the GaN-based bottom layer by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer includes: Performing high-energy argon ion bombardment treatment on the GaN-based bottom layer to obtain an activated surface with surface dangling bonds; Performing pulsed deposition of magnesium atoms on the activated surface by in-situ plasma-assisted molecular beam epitaxy technology to obtain a magnesium precursor layer with a single atomic layer thickness; Performing nitrogen plasma co-doping treatment on the magnesium precursor layer to obtain a doping transition layer with a high hole concentration; Performing two-dimensional growth mode regulation on the doping transition layer by in-situ reflection high-energy electron diffraction to obtain a p-type epitaxial layer with atomic-level flatness; Performing rapid thermal annealing activation treatment on the p-type epitaxial layer to obtain a p-type doped layer.

6. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, characterized in that, The atomic layer etching and surface plasma oxidation treatment of the p-type doped layer to obtain an ultra-thin p-GaN active layer includes: Performing digital atomic layer etching on the p-type doped layer to obtain a surface structure with atomic-level steps; Depositing an oxide layer on the surface structure through a remote plasma source to obtain a composite interface with a nano-oxide layer; Performing selective wet etching on the composite interface to obtain an ultra-thin active region with a uniform thickness; Performing real-time thickness monitoring on the ultra-thin active region by in-situ ellipsometer to obtain a p-GaN thin layer with a uniform thickness; Performing surface plasma oxidation treatment on the p-GaN thin layer to obtain an ultra-thin p-GaN active layer.

7. The preparation method of the p-GaN ultra-thin gate layer according to claim 1, wherein The interface state regulation of the ultra-thin p-GaN active layer by in-situ annealing and surface passivation treatment to obtain a p-GaN ultra-thin gate layer with a low interface state density includes: Performing nitrogen atmosphere annealing treatment on the ultra-thin p-GaN active layer by in-situ annealing and surface passivation treatment to obtain a transition structure with a reconstructed surface; Growing a silicon nitride passivation layer on the transition structure by in-situ plasma chemical vapor deposition to obtain a composite layer with a double-layer passivation structure; Performing hydrogen plasma passivation treatment on the composite layer to obtain an interface structure with a low defect density; Performing energy band regulation on the interface structure by in-situ X-ray photoelectron spectroscopy to obtain a gate layer with an optimized energy band structure; Performing a final annealing treatment on the gate layer to obtain a p-GaN ultra-thin gate layer with a low interface state density.

8. A preparation system for a p-GaN ultra-thin gate layer, characterized in that, Including: A first processing module for performing plasma-enhanced chemical vapor deposition treatment on a substrate to obtain a nitrided substrate; A first growth module for growing a buffer layer on the nitrided substrate by pulse modulation growth technology to obtain a buffer structure with a stress modulation layer; A second growth module for performing alternating injection growth of trimethylgallium source and ammonia source on the buffer structure by an alternating pulse injection method to obtain a high-quality GaN-based bottom layer; A doping module for performing magnesium doping on the GaN-based bottom layer by in-situ plasma-assisted molecular beam epitaxy technology to obtain a p-type doped layer; A second processing module for performing atomic layer etching and surface plasma oxidation treatment on the p-type doped layer to obtain an ultra-thin p-GaN active layer; A regulation module, configured to perform interface state regulation on the ultra-thin p-GaN active layer through in-situ annealing and surface passivation treatment, so as to obtain a p-GaN ultra-thin gate layer with a low interface state density.

9. A computer device, comprising a memory and a processor, wherein a computer program is stored in the memory, characterized in that, When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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