Boron nitride intercalated Schottky barrier diode and preparation method thereof
By inserting the boron nitride layer into the Schottky barrier diode and optimizing the electrode contact, the problems of low breakdown voltage and large parasitic effects of the existing Schottky barrier diode are solved, and the high-frequency response capability and stability are improved.
Patent Information
- Application Number
- CN202510226310.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-27
- Publication Date
- 2025-05-16
AI Technical Summary
The existing Schottky barrier diodes have problems such as low breakdown voltage and large parasitic effects, which leads to slow high-frequency response, low stability and high power consumption, making it difficult to meet the actual application needs.
By inserting a boron nitride (h-BN) layer into a traditional GaN kischottky barrier diode structure, the breakdown voltage is increased using its high breakdown field strength characteristics, and a first groove is formed by etching in the h-BN layer and the u-GaN layer, Schottky contact and ohmic contact metal electrodes are made, and the contact area between the electrode and the semiconductor material is controlled to reduce the parasitic effect.
It improves the breakdown voltage and electrical performance of Schottky barrier diodes, reduces parasitic effects, improves the high-frequency response and stability of the device, and is suitable for high-frequency and high-power applications.
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Figure CN120018527A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of semiconductor technology, and in particular to a boron nitride intercalated Schottky barrier diode and a preparation method thereof. Background Art
[0002] Schottky barrier diodes, also known as hot carrier diodes, are core devices in power electronic products based on the principle of metal-semiconductor junctions formed by the contact between metal and semiconductor. The device needs to have low turn-on voltage, specific on-resistance, low reverse leakage current and high breakdown voltage to reduce power loss. Gallium nitride (GaN) is a wide bandgap semiconductor material. Due to its large bandgap width and high electron mobility, AlGaN / GaN Schottky barrier diodes (SBDs) based on sapphire or silicon carbide (SiC) substrates have better performance than other material systems and have broad application prospects. Si / GaN-based Schottky barrier diodes have shown strong commercial potential due to their good performance and low cost. However, existing Schottky barrier diodes have problems such as low breakdown voltage and large parasitic effects, resulting in slow high-frequency response, low stability, and high power consumption, which are difficult to meet the needs of actual applications.
[0003] There is currently no effective technical solution to the above problems. Summary of the invention
[0004] The purpose of the present application is to provide a boron nitride intercalated Schottky barrier diode and a preparation method thereof, so as to improve the breakdown voltage of the diode and reduce parasitic effects, so as to solve the problems of slow high-frequency response, low stability and high power consumption of the diode.
[0005] In a first aspect, the present application provides a method for preparing a boron nitride intercalated Schottky barrier diode, the method comprising the following steps: S1. Depositing a buffer layer, an n-GaN layer, a u-GaN layer and an h-BN layer in sequence from bottom to top on a substrate; S2, etching the u-GaN layer and the h-BN layer to form a first groove; S3, making a Schottky contact metal electrode on the h-BN layer and making an ohmic contact metal electrode on the first groove; S4. Form a passivation layer on the h-BN layer based on plasma enhanced chemical vapor deposition, and partially etch the passivation layer to expose the Schottky contact metal electrode and the ohmic contact metal electrode.
[0006] The method for preparing a boron nitride intercalated Schottky barrier diode of the present application inserts an h-BN layer to utilize its high breakdown field strength characteristics to increase the breakdown voltage of the device, and at the same time, by making an ohmic contact metal electrode on the first groove, the contact area between the electrode and the semiconductor material is effectively controlled to reduce parasitic effects. In addition, by forming a passivation layer, the surface characteristics of the device are further improved.
[0007] In the method for preparing the boron nitride intercalated Schottky barrier diode, the bottom area of the first groove is larger than the bottom area of the ohmic contact metal electrode.
[0008] In this example, by increasing the bottom area of the first groove, a larger contact area can be provided for the ohmic contact metal electrode, thereby reducing the contact resistance, improving the electrical performance of the device, improving the quality of the ohmic contact, and reducing the current concentration effect, which is beneficial to improving the reliability and life of the device, and is beneficial to improving the stability and yield of the manufacturing process.
[0009] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the passivation layer is made based on at least one material of Si3N4, SiO2 and Al2O3.
[0010] The passivation layer material selection scheme in the preparation method of the boron nitride intercalated Schottky barrier diode of the present application is combined with the h-BN layer, which can give full play to the excellent electrical properties of boron nitride, while further improving the overall performance and reliability of the device through the protective effect of the passivation layer, and can also effectively improve the electrical characteristics and long-term stability of the device.
[0011] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the material of the ohmic contact metal electrode is metal titanium, metal aluminum, metal nickel, metal gold or molybdenum-platinum alloy.
[0012] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the Schottky contact metal electrode is formed by stacking metal nickel and metal gold, or by stacking metal nickel and metal platinum.
[0013] The method for preparing a Schottky barrier diode with a boron nitride intercalation layer, wherein the n-GaN layer is doped with silicon at a doping concentration of 2×10 18 cm -3 .
[0014] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the h-BN layer is etched by an ICP dry etching process based on a mixed gas composed of CHF3 and CF4 with a mixing ratio of 10:1, an ICP source power of 150W and an RF bias power of 50W.
[0015] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the ohmic contact metal electrode is made based on electron beam evaporation treatment and annealing treatment in a nitrogen atmosphere.
[0016] The method for preparing the boron nitride intercalated Schottky barrier diode, wherein the substrate is a silicon substrate or a sapphire substrate.
[0017] In a second aspect, the present application further provides a boron nitride intercalated Schottky barrier diode, which is manufactured based on the preparation method of the boron nitride intercalated Schottky barrier diode provided in the first aspect.
[0018] The boron nitride intercalated Schottky barrier diode of the present application is manufactured based on the preparation method of the boron nitride intercalated Schottky barrier diode provided in the first aspect. It inserts an h-BN layer in the diode structure to enhance the breakdown voltage, and at the same time, an ohmic contact metal electrode is made on the first groove to effectively control the contact area between the electrode and the semiconductor material, thereby reducing the parasitic effect. By setting a passivation layer, the surface characteristics of the device are further improved, and the influence of the surface state on the device performance is reduced. It has a higher breakdown voltage and lower parasitic effects, and exhibits excellent performance in high-frequency and high-power applications.
[0019] As can be seen from the above, the present application provides a boron nitride intercalated Schottky barrier diode and a preparation method thereof, wherein the preparation method of the boron nitride intercalated Schottky barrier diode inserts an h-BN layer into the traditional GaN-based Schottky barrier diode structure, and uses its high breakdown field strength characteristics to improve the breakdown voltage of the device. At the same time, by etching the h-BN layer and the u-GaN layer to form a first groove, the contact area between the electrode and the semiconductor material is effectively controlled to reduce parasitic effects. In addition, a Schottky contact metal electrode and an ohmic contact metal electrode are respectively made on the h-BN layer and the first groove, so that the Schottky contact metal electrode is connected to the h-BN layer, and the ohmic contact metal electrode is connected to the n-GaN layer, thereby optimizing the electrode performance and reducing the contact resistance. Finally, a passivation layer is formed by plasma enhanced chemical vapor deposition, which further improves the surface characteristics of the device and reduces the influence of the surface state on the device performance. The boron nitride intercalated Schottky barrier diode prepared by this method has a higher breakdown voltage and lower parasitic effects, and exhibits excellent performance in high-frequency and high-power applications. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 Flow chart of a method for preparing a boron nitride intercalated Schottky barrier diode provided in an embodiment of the present application.
[0021] Figure 2 A schematic diagram of the structure of a Schottky barrier diode with a boron nitride intercalation layer provided in an embodiment of the present application.
[0022] Figure numerals: 1. substrate; 2. buffer layer; 3. n-GaN layer; 4. u-GaN layer; 5. h-BN layer; 6. first groove; 7. Schottky contact metal electrode; 8. Ohmic contact metal electrode; 9. passivation layer. DETAILED DESCRIPTION
[0023] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.
[0024] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.
[0025] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0026] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.
[0027] The disclosure below provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplicity and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the present invention provides various specific examples of processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.
[0028] As a core device in power electronic products, Schottky barrier diodes face technical problems of low breakdown voltage and large parasitic effects in practical applications. These problems seriously affect the performance and reliability of the device. Specifically, the low breakdown voltage limits the use of the device in high-voltage applications, while the large parasitic effects lead to slow high-frequency response, low stability and high power consumption. The existence of these problems makes it difficult for existing Schottky barrier diodes to meet the growing demand for high-performance power electronic applications.
[0029] In a typical high-frequency switching power supply system, Schottky barrier diodes are often used as rectifying devices. For example, in a switching power supply with an operating frequency of 1MHz and an output voltage of 100V, the existing GaN-based Schottky barrier diodes may only be able to withstand a reverse voltage of 200V, which may cause device breakdown in voltage transient or surge conditions. At the same time, due to the presence of parasitic capacitance and inductance, the switching loss of the device at high frequencies increases significantly. Specifically, when the switching frequency is increased from 100kHz to 1MHz, the switching loss may increase by more than 5 times. This not only reduces the efficiency of the power supply system, but also increases the difficulty of heat dissipation design. In addition, parasitic effects can also cause voltage and current oscillations, generate electromagnetic interference, and affect the stability and reliability of the system.
[0030] If these technical problems cannot be effectively solved, the development of power electronic systems will be seriously restricted. First, the low breakdown voltage limits the use of devices in high-voltage applications, which means that in some occasions where high voltage resistance is required, multiple devices may need to be used in series, increasing system complexity and cost. Secondly, the degradation of high-frequency performance caused by large parasitic effects will hinder the development of switching power supplies to higher frequencies, thereby limiting the miniaturization and lightweight of power supply systems. In addition, due to the increase in switching losses, the system efficiency is reduced, which not only increases energy consumption, but also increases the difficulty of heat dissipation design. If these problems are not solved, it will seriously affect the development of a new generation of high-efficiency, high-power density power electronic systems. It can be seen that the development of a new Schottky barrier diode structure and preparation method that can overcome these technical obstacles is of great technical significance.
[0031] Aiming at the problems of low breakdown voltage and large parasitic effect of Schottky barrier diode, this application conducts in-depth analysis and exploration.
[0032] First, please refer to Figure 1 Some embodiments of the present application provide a method for preparing a Schottky barrier diode with a boron nitride intercalation layer, the method comprising the following steps: S1, sequentially depositing a buffer layer 2, an n-GaN layer 3, a u-GaN layer 4 and an h-BN layer 5 arranged from bottom to top on a substrate 1; S2, etching the u-GaN layer 4 and the h-BN layer 5 to form a first groove 6; S3, forming a Schottky contact metal electrode 7 on the h-BN layer 5 and forming an ohmic contact metal electrode 8 on the first groove 6; S4. Form a passivation layer 9 on the h-BN layer 5 based on plasma enhanced chemical vapor deposition, and partially etch the passivation layer 9 to expose the Schottky contact metal electrode 7 and the ohmic contact metal electrode 8.
[0033] Specifically, considering the need to increase the breakdown voltage, the present application considers the possibility of introducing new materials. Boron nitride, as an ultra-wide bandgap semiconductor, has excellent electrical properties and high breakdown field strength, and has become a potential choice. However, directly replacing gallium nitride with boron nitride may bring new problems, such as compatibility with existing processes. Therefore, the present application proposes the idea of using boron nitride as an intercalation material, which can not only utilize its high breakdown field strength characteristics, but also maintain compatibility with existing GaN-based devices. Therefore, step S1 is used to form an h-BN layer 5 located between u-GaN and the Schottky contact metal electrode 7.
[0034] More specifically, in terms of electrode design, the present application proposes a solution for separating Schottky contact and ohmic contact. By making a Schottky contact metal electrode 7 and an ohmic contact metal electrode 8 on the h-BN layer 5 and the first groove 6, respectively, the contact characteristics of each can be optimized, the contact resistance can be reduced, and the device performance can be further improved.
[0035] More specifically, considering the influence of surface states on device performance, the present application also introduces a passivation layer 9 technology. Forming the passivation layer 9 by plasma enhanced chemical vapor deposition can improve the surface characteristics of the device, reduce the adverse effects of the surface states, and improve the stability and reliability of the device.
[0036] More specifically, the substrate 1 refers to a base for growing semiconductor materials; the buffer layer 2 refers to a transition layer between the substrate 1 and the n-GaN layer 3, which can be specifically implemented by AlN or AlGaN materials; the n-GaN layer 3 refers to a gallium nitride layer doped with n-type impurities, which can be specifically achieved by growth through a MOCVD process; the u-GaN layer 4 refers to an undoped gallium nitride layer, which can be specifically achieved by growth through a MOCVD process; the h-BN layer 5 refers to a hexagonal boron nitride layer, which can be specifically achieved by growth through a MOCVD or PECVD process; the Schottky contact metal electrode 7 refers to a metal electrode that forms a Schottky contact with a semiconductor; the ohmic contact metal electrode 8 refers to a metal electrode that forms an ohmic contact with a semiconductor; and the passivation layer 9 refers to an insulating layer used to protect the surface of the device.
[0037] More specifically, the n-GaN layer 3 and the u-GaN layer 4 constitute the main structure of the device, wherein the n-GaN layer 3 provides electrons, the u-GaN layer 4 serves as a drift layer, and the h-BN layer 5 serves as an intercalation structure located above the u-GaN layer 4, and its high breakdown field strength characteristics help to improve the breakdown voltage of the device.
[0038] The preparation method of the boron nitride intercalated Schottky barrier diode of the embodiment of the present application inserts an h-BN layer 5 into the traditional GaN-based Schottky barrier diode structure, and uses its high breakdown field strength characteristics to improve the breakdown voltage of the device. At the same time, by etching the h-BN layer 5 and the u-GaN layer 4 to form a first groove 6, the contact area between the electrode and the semiconductor material is effectively controlled to reduce parasitic effects. In addition, a Schottky contact metal electrode 7 and an ohmic contact metal electrode 8 are respectively made on the h-BN layer 5 and the first groove 6, so that the Schottky contact metal electrode 7 is connected to the h-BN layer 5 and the ohmic contact metal electrode 8 is connected to the n-GaN layer 3, thereby optimizing the electrode performance and reducing the contact resistance. Finally, a passivation layer 9 is formed by plasma enhanced chemical vapor deposition, which further improves the surface characteristics of the device and reduces the influence of the surface state on the device performance. The boron nitride intercalated Schottky barrier diode prepared by this method has a higher breakdown voltage and lower parasitic effects, and exhibits excellent performance in high-frequency and high-power applications.
[0039] In some preferred embodiments, the bottom area of the first groove 6 is larger than the bottom area of the ohmic contact metal electrode 8 .
[0040] Specifically, by increasing the bottom area of the first groove 6, a larger contact area can be provided for the ohmic contact metal electrode 8, thereby reducing the contact resistance, improving the electrical performance of the device, improving the quality of the ohmic contact, and reducing the current concentration effect, which is beneficial to improving the reliability and life of the device, and is beneficial to improving the stability and yield of the manufacturing process.
[0041] More specifically, if Figure 2 As shown, in this embodiment, the passivation layer 9 also covers the exposed portions of the n-GaN layer 3 and the u-GaN layer 4 generated during the etching process of step S2 to protect the n-GaN layer 3 and the u-GaN layer 4 .
[0042] More specifically, the h-BN layer 5 as an intercalation layer can effectively reduce the leakage current at the Schottky contact, while the increased ohmic contact area can ensure good current conduction. The two work together to achieve better device performance.
[0043] In some preferred embodiments, the passivation layer 9 is made of at least one material selected from the group consisting of Si 3 N 4 , SiO 2 and Al 2 O 3 .
[0044] Specifically, the material selection of the passivation layer 9 has an important influence on the performance and reliability of the boron nitride intercalated Schottky barrier diode. Among them, Si3N4 has good insulation and chemical stability, and can effectively block the diffusion of impurities. SiO2 has excellent dielectric properties and interface characteristics, and can reduce the interface state density. Al2O3 has a high dielectric constant and good thermal stability, and can improve the voltage resistance of the device. Selecting at least one of these materials to make the passivation layer 9 can achieve the following effects: protect the device surface and prevent the influence of the external environment on the device; reduce surface leakage current and increase the breakdown voltage of the device; improve the thermal stability and reliability of the device; optimize the interface characteristics, reduce the interface state density, and improve the device performance.
[0045] More specifically, the present application provides a solution for using a variety of passivation layer 9 materials in combination. For example, a double-layer structure of Si3N4 and SiO2 can be used to utilize the chemical stability of Si3N4 and the good interface properties of SiO2, or an Al2O3 / SiO2 double-layer structure can be used to combine the high dielectric constant of Al2O3 and the low interface state density characteristics of SiO2.
[0046] More specifically, the material selection scheme for the passivation layer 9 in the method for preparing the boron nitride intercalated Schottky barrier diode of the embodiment of the present application is combined with the boron nitride intercalation structure (i.e., the h-BN layer 5), which can give full play to the excellent electrical properties of boron nitride, while further improving the overall performance and reliability of the device through the protective effect of the passivation layer 9, and can also effectively improve the electrical characteristics and long-term stability of the device.
[0047] In some preferred embodiments, the ohmic contact metal electrode 8 is made of metal titanium, metal aluminum, metal nickel, metal gold or molybdenum-platinum alloy.
[0048] Specifically, the above materials have good electrical conductivity and contact characteristics with semiconductor materials, can form stable ohmic contact, reduce contact resistance, and improve the electrical performance of the device.
[0049] In some preferred embodiments, the Schottky contact metal electrode 7 is formed by stacking metal nickel and metal gold, or by stacking metal nickel and metal platinum.
[0050] Specifically, the stacked structure of metal nickel and metal gold or metal platinum can form a good Schottky contact. Metal nickel as the bottom layer can form a stable contact with gallium nitride, while metal gold or metal platinum as the top layer can provide good conductivity and oxidation resistance. This stacked structure can reduce contact resistance and improve the conduction performance of the device, while maintaining a high Schottky barrier height, which is conducive to reducing reverse leakage current.
[0051] More specifically, the stacked structure of the Schottky contact metal electrode 7 proposed in the present application can be realized in a variety of ways. For example, a physical vapor deposition method such as electron beam evaporation or magnetron sputtering can be used to sequentially deposit metal nickel and metal gold (or metal platinum).
[0052] More specifically, the method for preparing a boron nitride intercalated Schottky barrier diode in an embodiment of the present application optimizes the Schottky contact performance by selecting a suitable metal combination and stacking structure and inserting an h-BN layer 5 into the u-GaN layer 4 and the Schottky contact metal electrode 7. This optimization not only improves the electrical characteristics of the entire diode, but also enhances the reliability of the device.
[0053] In some preferred embodiments, the n-GaN layer 3 is doped with silicon, with a doping concentration of 2×10 18 cm -3 .
[0054] Specifically, the above-mentioned doping treatment achieves an optimized balance between the conduction characteristics and the blocking performance, so that the diode manufactured by the preparation method of the boron nitride intercalated Schottky barrier diode in the embodiment of the present application is particularly suitable for high-frequency and high-power scenarios (such as 5G communications, fast switching power supplies), and is a design choice that takes into account both performance and reliability.
[0055] In some preferred embodiments, the h-BN layer 5 is etched by an ICP dry etching process based on a mixed gas consisting of CHF 3 and CF 4 with a mixing ratio of 10:1, an ICP source power of 150 W, and an RF bias power of 50 W.
[0056] Specifically, the above process parameter settings achieve high-quality etching of the h-BN layer 5, which is mainly manifested in: 1. A mixed gas of CHF3 and CF4 is selected as the etching gas. The combination of these two gases can provide a suitable etching chemical reaction. CHF3 provides fluorine free radicals, which helps to etch the h-BN layer 5, while CF4 can increase the etching rate. 2. The ratio of the mixed gas is set to 10:1. This ratio can effectively balance the etching rate and selectivity. A higher ratio of CHF3 can ensure sufficient etching reaction, while a small amount of CF4 can improve etching efficiency.
[0057] 3. The ICP source power is set to 150W to generate plasma of appropriate density, ensuring that there are enough active particles participating in the reaction during the etching process.
[0058] 4. The RF bias power is set to 50 W to control the ion bombardment energy, which can ensure the etching efficiency while avoiding excessive damage to the h-BN layer 5.
[0059] More specifically, the method for preparing a boron nitride intercalated Schottky barrier diode of the embodiment of the present application etches the h-BN layer 5 by using the above-mentioned process parameters, which can effectively solve the problems of uneven etching of the h-BN layer 5, high side wall roughness, and difficult to control etching depth in the prior art, and can effectively improve the etching uniformity, etching rate and selectivity accuracy.
[0060] In some preferred embodiments, the ohmic contact metal electrode 8 is manufactured based on electron beam evaporation and annealing in a nitrogen atmosphere.
[0061] Specifically, electron beam evaporation treatment can accurately control the deposition process of the metal film, ensuring the uniformity and quality of the ohmic contact metal electrode 8; annealing treatment under a nitrogen atmosphere helps to improve the interface characteristics between the metal and the semiconductor, reduce the contact resistance, improve the performance of the ohmic contact, and prevent metal oxidation, while promoting the mutual diffusion and reaction of metal atoms and semiconductor surface atoms to form good interface characteristics.
[0062] In some preferred embodiments, the substrate 1 is a silicon substrate or a sapphire substrate.
[0063] Specifically, silicon substrates have good thermal conductivity and low cost, which is conducive to reducing the thermal resistance and production cost of devices. They also have good mechanical strength and stability, which helps to improve the reliability of devices. Sapphire substrates have excellent insulation and chemical stability, which can reduce parasitic capacitance and leakage current, improve the electrical performance of devices, and have good lattice matching with gallium nitride, which is conducive to improving the quality of epitaxial layers.
[0064] In some preferred embodiments, the thickness of the h-BN layer 5 is 5-15 nm.
[0065] Specifically, the method for preparing the boron nitride intercalated Schottky barrier diode of the embodiment of the present application can effectively adjust the electrical properties of the device by controlling the thickness of the h-BN layer 5 within the range of 5-15nm. Within this range, the h-BN layer 5 can not only exert its excellent electrical properties and high breakdown field strength characteristics, but also will not be too thick to affect the normal operation of the device.
[0066] Second, please refer to Figure 2 Some embodiments of the present application also provide a boron nitride intercalated Schottky barrier diode, which is manufactured based on the preparation method of the boron nitride intercalated Schottky barrier diode provided in the first aspect.
[0067] The boron nitride intercalated Schottky barrier diode of the embodiment of the present application is manufactured based on the preparation method of the boron nitride intercalated Schottky barrier diode provided in the first aspect. It inserts an h-BN layer 5 into the diode structure to enhance the breakdown voltage. At the same time, an ohmic contact metal electrode 8 is made on the first groove 6 to effectively control the contact area between the electrode and the semiconductor material, thereby reducing the parasitic effect. By setting a passivation layer 9, the surface characteristics of the device are further improved, and the influence of the surface state on the device performance is reduced. It has a higher breakdown voltage and lower parasitic effects, and exhibits excellent performance in high-frequency and high-power applications.
[0068] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.
[0069] The above are only some embodiments of the present invention. For those skilled in the art, several modifications and improvements can be made without departing from the creative concept of the present invention, which all belong to the protection scope of the present invention.
Claims
1. A method for preparing a boron nitride intercalated Schottky barrier diode, characterized in that: The method comprises the following steps: S1. Depositing a buffer layer, an n-GaN layer, a u-GaN layer and an h-BN layer in sequence from bottom to top on a substrate; S2, etching the u-GaN layer and the h-BN layer to form a first groove; S3, forming a Schottky contact metal electrode on the h-BN layer and an ohmic contact metal electrode on the first groove; S4. Form a passivation layer on the h-BN layer based on plasma enhanced chemical vapor deposition, and partially etch the passivation layer to expose the Schottky contact metal electrode and the ohmic contact metal electrode.
2. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The bottom area of the first groove is larger than the bottom area of the ohmic contact metal electrode.
3. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The passivation layer is made of at least one material selected from the group consisting of Si3N4, SiO2 and Al2O3.
4. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The ohmic contact metal electrode is made of metal titanium, metal aluminum, metal nickel, metal gold or molybdenum-platinum alloy.
5. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The Schottky contact metal electrode is formed by stacking metal nickel and metal gold, or by stacking metal nickel and metal platinum.
6. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The n-GaN layer is doped with silicon, with a doping concentration of 2×10 18 cm -3 .
7. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The h-BN layer was etched by an ICP dry etching process using a mixed gas of CHF3 and CF4 with a mixing ratio of 10:1, an ICP source power of 150 W, and an RF bias power of 50 W.
8. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The ohmic contact metal electrode is manufactured based on electron beam evaporation and annealing in a nitrogen atmosphere.
9. The method for preparing a boron nitride intercalated Schottky barrier diode according to claim 1, characterized in that: The substrate is a silicon substrate or a sapphire substrate.
10. A boron nitride intercalated Schottky barrier diode, characterized in that: The Schottky barrier diode is manufactured based on the preparation method of the boron nitride intercalated diode as described in any one of claims 1 to 9.