Non-polar gallium nitride device and manufacturing method thereof
By introducing a low-interface diamond-non-polar gallium nitride heterointerface structure into gallium nitride devices, the device thermal degradation problem is solved, efficient heat dissipation and performance improvement is achieved, and it is suitable for the manufacturing of high-power and high-frequency devices.
Patent Information
- Application Number
- CN202510572923.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-08-01
AI Technical Summary
GaN-based high-frequency high-power rectifier devices generate a lot of heat during operation, resulting in thermal degradation or thermal breakdown, limiting the device's RF rectifier power and performance.
The non-polar gallium nitride device structure is adopted, including diamond layer, non-polar gallium nitride layer, passivation layer and electrode, and the formation of a heterogeneous interface with a low interface state and an efficient heat dissipation structure can reduce RF loss and improve heat dissipation performance.
It effectively reduces RF loss, improves the heat dissipation performance and overall performance of the device, and is suitable for the preparation and application of high-power high-frequency gallium nitride devices.
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Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductors, and particularly to a non-polar gallium nitride device and a manufacturing method thereof. Background Art
[0002] As a representative of the third-generation semiconductor materials, gallium nitride (GaN) has many excellent characteristics, such as a high critical breakdown electric field, a high electron mobility, a high two-dimensional electron gas concentration, and good high-temperature working ability, etc. Third-generation semiconductor devices based on gallium nitride, such as high electron mobility transistors, heterojunction field effect transistors, and Schottky diodes, etc., have been applied, and have obvious advantages particularly in fields such as radio frequency and microwave that require high power and high frequency.
[0003] At present, the current flowing through the high-frequency high-power rectifier device based on gallium nitride during operation is extremely large, and a large amount of heat may be generated, thereby causing thermal degradation or thermal breakdown of the device. Therefore, the radio frequency rectification power of the gallium nitride-based device is limited, and finally the performance of the gallium nitride-based device is reduced. Summary of the Invention
[0004] In view of this, the purpose of the present application is to provide a non-polar gallium nitride device and a manufacturing method thereof, which can improve the heat dissipation of the non-polar gallium nitride device, reduce radio frequency loss, and finally improve the performance of the non-polar gallium nitride device.
[0005] The present application provides a non-polar gallium nitride device, which includes a diamond layer, a non-polar gallium nitride layer, a passivation layer, a first electrode, and a second electrode stacked in sequence;
[0006] A heterojunction interface is formed between the diamond layer and the non-polar gallium nitride layer, and the interface state concentration of the heterojunction interface satisfies the low interface state concentration condition;
[0007] The first electrode and the second electrode penetrate through the passivation layer to the non-polar gallium nitride layer.
[0008] Optionally, the non-polar gallium nitride layer is an m-plane gallium nitride layer or an a-plane gallium nitride layer;
[0009] A heterojunction interface is formed between the diamond layer and the m-plane gallium nitride layer, or a heterojunction interface is formed between the diamond layer and the a-plane gallium nitride layer.
[0010] Optionally, the diamond layer is a polycrystalline diamond layer.
[0011] Optionally, the non-polar gallium nitride layer is an N-type doped non-polar gallium nitride layer.
[0012] Optionally, the direction in which the first electrode and the second electrode penetrate through the passivation layer is the polar direction of the non-polar gallium nitride layer.
[0013] Optionally, the material of the passivation layer is silicon nitride or aluminum oxide.
[0014] Optionally, the first electrode is a Schottky contact electrode, and the second electrode is an ohmic contact electrode.
[0015] Optionally, the first electrode is a stacked structure, and the stacked structure is a nickel-gold stack or a platinum-gold stack.
[0016] The present application provides a method for manufacturing a non-polar gallium nitride device, the method comprising:
[0017] forming a non-polar gallium nitride layer on the substrate;
[0018] removing the substrate and forming a diamond layer on a first surface of the non-polar gallium nitride layer, where the first surface is a surface of the non-polar gallium nitride layer after removing the substrate;
[0019] forming a passivation layer on a second surface of the non-polar gallium nitride layer, wherein the second surface is disposed opposite to the first surface;
[0020] The passivation layer is etched to the non-polar gallium nitride layer to form a first trench and a second trench, and a first electrode and a second electrode are formed in the first trench and the second trench respectively.
[0021] Optionally, before forming the non-polar gallium nitride layer on the substrate, the method further includes:
[0022] performing a heat treatment on the substrate;
[0023] The heat-treated substrate is subjected to a nitriding treatment.
[0024] The present application provides a non-polar gallium nitride device, which includes a diamond layer, a non-polar gallium nitride layer, a passivation layer, a first electrode, and a second electrode stacked in sequence. The first electrode and the second electrode extend through the passivation layer to the non-polar gallium nitride layer. The passivation layer is disposed on the surface of the non-polar gallium nitride layer to suppress surface leakage and trap effects, thereby improving the performance of the non-polar gallium nitride device. A heterointerface is formed between the diamond layer and the non-polar gallium nitride layer. The interface state concentration of the heterointerface meets a low interface state concentration condition, that is, the interface state concentration of the heterointerface between the non-polar gallium nitride layer and the diamond layer is low. This not only reduces radio frequency loss, but also enables efficient heat dissipation through the diamond layer, thereby improving the heat dissipation performance of the non-polar gallium nitride device and ultimately improving the performance of the non-polar gallium nitride device. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.
[0026] Figure 1 Shows a schematic structural diagram of a non-polar gallium nitride device provided by an embodiment of the present application;
[0027] Figure 2 Shows a schematic structural diagram of a GaN(100)-C(310) heterojunction model provided by an embodiment of the present application;
[0028] Figure 3 Shows a schematic diagram of the total density of states and partial density of states based on the GaN(100)-C(310) heterojunction model provided by an embodiment of the present application;
[0029] Figure 4 Shows a schematic flowchart of a manufacturing method of a non-polar gallium nitride device provided by an embodiment of the present application;
[0030] Figures 5 - 7 Shows a schematic structural diagram of a non-polar gallium nitride device manufactured by the manufacturing method of the non-polar gallium nitride device provided by an embodiment of the present application. Detailed implementation manners
[0031] In order to enable those skilled in the art to better understand the solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.
[0032] Many specific details are set forth in the following description in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein. Those skilled in the art can make similar generalizations without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.
[0033] The present application is described in detail in conjunction with the schematic diagrams. When detailing the embodiments of the present application, for the convenience of description, the cross-sectional views showing the device structure will be enlarged locally in a non-general proportion, and the schematic diagrams are only examples and should not limit the scope of protection of the present application herein. In addition, in actual production, three-dimensional spatial dimensions including length, width, and depth should be included.
[0034] At present, the current passing through the existing gallium nitride-based high-frequency high-power rectifying device during operation is extremely large, which may generate a large amount of heat, thereby causing thermal degradation or thermal breakdown of the device. Therefore, the radio frequency rectifying power of the gallium nitride-based device is limited, and ultimately the performance of the gallium nitride-based device is reduced.
[0035] Based on this, the present application provides a non-polar gallium nitride device. The non-polar gallium nitride device includes a diamond layer, a non-polar gallium nitride layer, a passivation layer, a first electrode, and a second electrode that are sequentially stacked. The first electrode and the second electrode penetrate through the passivation layer to the non-polar gallium nitride layer. The passivation layer is disposed on the surface of the non-polar gallium nitride layer and is used to suppress surface leakage and trap effects, thereby improving the performance of the non-polar gallium nitride device; a heterointerface is formed between the diamond layer and the non-polar gallium nitride layer, and the interface state concentration of the heterointerface satisfies the low interface state concentration condition, that is, the interface state concentration of the heterointerface between the non-polar gallium nitride layer and the diamond layer is relatively low, which can not only reduce radio frequency loss, but also utilize the diamond layer to achieve efficient heat dissipation, improve the heat dissipation performance of the non-polar gallium nitride device, and ultimately improve the performance of the non-polar gallium nitride device.
[0036] In order to better understand the technical solutions and technical effects of the present application, specific embodiments will be described in detail below with reference to the accompanying drawings.
[0037] See Figure 1 , which is a schematic structural diagram of a non-polar gallium nitride device provided by an embodiment of the present application.
[0038] The non-polar gallium nitride device provided in this embodiment includes: a diamond layer 110, a non-polar gallium nitride layer 120, a passivation layer 130, a first electrode 141, and a second electrode 142 that are sequentially stacked.
[0039] In the embodiment of the present application, the non-polar gallium nitride (GaN) layer 120 is disposed on the diamond (C) layer 110. The diamond layer 110 and the non-polar gallium nitride layer 12 are in direct contact. A heterointerface is formed between the diamond layer 110 and the non-polar gallium nitride layer 120, and the interface state concentration of the heterointerface satisfies the low interface state concentration condition, that is, the interface state concentration of the heterointerface between the non-polar gallium nitride layer 120 and the diamond layer 110 is relatively low, which can reduce radio frequency loss.
[0040] As a possible implementation manner, the low interface state concentration condition may be that the interface state concentration of the heterointerface between the diamond layer 110 and the non-polar gallium nitride layer 120 is less than the interface state concentration threshold.
[0041] As another possible implementation manner, the low interface state concentration condition may be that the interface state concentration of the heterointerface between the diamond layer 110 and the non-polar gallium nitride layer 120 is less than the interface state concentration of the heterointerface between the diamond layer 110 and the polar gallium nitride layer.
[0042] The interface state concentration between the diamond layer 110 and the non-polar gallium nitride layer 120 is extremely low, which is conducive to the formation of a low-loss interface-optimized GaN(100)-C(310) heterojunction model. Refer to Figure 2 as shown. Figure 2 In the atomic stick structure, GaN is on the left and diamond is on the right. Refer to Figure 3 as shown, Figure 3 which shows the total density of states and the partial density of states calculated based on the GaN(100)-C(310) heterojunction model. The interface states of the heterojunction formed between the non-polar gallium nitride layer 120 and the diamond layer 110 are significantly reduced compared with the interface states formed between the polar gallium nitride layer and the diamond layer 110 below the conduction band.
[0043] In the embodiments of the present application, the non-polar gallium nitride layer 120 is an m-plane gallium nitride layer or an a-plane gallium nitride layer. When the non-polar gallium nitride layer 120 is an m-plane gallium nitride layer, a heterojunction interface is formed between the diamond layer 110 and the m-plane gallium nitride layer. When the non-polar gallium nitride layer 120 is an a-plane gallium nitride layer, a heterojunction interface is formed between the diamond layer 110 and the a-plane gallium nitride layer.
[0044] As an example, Figure 2 and Figure 3 schematically show the GaN(100)-C(310) heterojunction model and the total density of states and the partial density of states between the m-plane gallium nitride layer and the diamond layer 110.
[0045] As a possible implementation, the non-polar gallium nitride layer 120 is an N-type doped non-polar gallium nitride layer. By doping the non-polar gallium nitride layer 120 with N-type, the non-polar gallium nitride layer 120 has a higher concentration of carriers, increasing the conduction performance of the non-polar gallium nitride device.
[0046] As an example, the N-type doping of the non-polar gallium nitride layer 120 can be achieved by doping the non-polar gallium nitride layer 120 with silicon elements.
[0047] In the embodiments of the present application, the diamond layer 110 is used to achieve efficient heat dissipation of the non-polar gallium nitride layer 120, improve the heat dissipation performance of the non-polar gallium nitride device, and ultimately improve the performance of the non-polar gallium nitride device.
[0048] As a possible implementation, the diamond layer 110 is a polycrystalline diamond layer. The thickness of the diamond layer 110 is greater than or equal to 100 μm and less than or equal to 300 μm.
[0049] In the embodiments of the present application, the passivation layer 130 is disposed on the surface of the non-polar gallium nitride layer 120 to suppress surface leakage and trap effects, thereby improving the performance of the non-polar gallium nitride device.
[0050] As a possible implementation, the material of the passivation layer 130 is silicon nitride or aluminum oxide. The thickness of the passivation layer 130 is 3 - 100 nm.
[0051] In the embodiment of the present application, the first electrode 141 and the second electrode 142 penetrate through the passivation layer 130 to the non-polar gallium nitride layer 120, so that the first electrode 141 and the second electrode 142 are respectively in contact with the non-polar gallium nitride layer 120.
[0052] As a possible implementation, the direction in which the first electrode 141 and the second electrode 142 penetrate through the passivation layer 130 is the polar direction of the non-polar gallium nitride layer 120. The polar direction of the non-polar gallium nitride layer 120 is the c-axis direction, that is, the direction in which the first electrode 141 and the second electrode 142 penetrate through the passivation layer 130 is the c-axis direction.
[0053] As a possible implementation, the first electrode 141 is a Schottky contact electrode, the second electrode 142 is an ohmic contact electrode, the first electrode 141 is the anode, and the second electrode 142 is the cathode, that is, the Schottky contact electrode is the anode and the ohmic contact electrode is the cathode. The non-polar gallium nitride device provided by the present application is a gallium nitride-based Schottky diode.
[0054] As a possible implementation, the material of the first electrode 141 or the second electrode 142 can be one or more of titanium, aluminum, nickel, platinum, and gold.
[0055] The first electrode 141 can also be a stacked structure, and the stacked structure is a nickel-gold stack or a platinum-gold stack.
[0056] As an example, the height of the first electrode 141 and the second electrode 142 is at least greater than 100 nm.
[0057] It can be seen that the non-polar gallium nitride device provided by the embodiment of the present application can realize a diamond-gallium nitride heterointerface with low interface states, which not only reduces the radio frequency loss, but also improves the heat dissipation performance of the device, and is beneficial to the performance improvement of gallium nitride-based high-power semiconductor devices. By utilizing the polarity of the gallium nitride material, there is no need to use a self-supporting GaN vertical structure wafer, which reduces the difficulty of the manufacturing process and is beneficial to the industrialization of gallium nitride high-power devices.
[0058] Based on the non-polar gallium nitride device provided in the above embodiments, the embodiment of the present application also provides a manufacturing method of a non-polar gallium nitride device. The working principle will be described in detail below with reference to the drawings.
[0059] See Figure 4 , which is a schematic flowchart of a manufacturing method of a non-polar gallium nitride device provided by the embodiment of the present application.
[0060] The manufacturing method of the non-polar gallium nitride device provided in this embodiment includes the following steps:
[0061] S101, forming a non-polar gallium nitride layer on a substrate.
[0062] In the embodiment of the present application, a substrate can be obtained, and then a non-polar gallium nitride layer is formed on the substrate, as shown in Figure 5 shown.
[0063] As a possible implementation, the substrate 101 can be an r-plane or m-plane sapphire substrate, and then a non-polar gallium nitride layer 120 is formed on the r-plane or m-plane sapphire substrate. Using an r-plane with the
[1120] crystal orientation or an m-plane sapphire with the
[1120] crystal orientation as the substrate 101, because of its high lattice matching degree with the non-polar gallium nitride layer 120 (such as the a-plane or m-plane), a non-polar gallium nitride layer 120 with high crystal quality can be grown on the a-plane and m-plane.
[0064] Specifically, an N-type doped non-polar gallium nitride layer 120 can be formed on the substrate 101 by epitaxial growth process to form a crystal structure.
[0065] In the embodiment of the present application, before forming the non-polar gallium nitride layer 120 on the substrate 101, the substrate 101 can also be processed to better combine the substrate 101 and the non-polar gallium nitride layer 120. The substrate 101 can be heat-treated first, and then the heat-treated substrate 101 can be nitrided.
[0066] As a possible implementation, first, the surface of the substrate 101 is cleaned with chemical reagents such as acetone and methanol, and the substrate 101 is heat-treated at 800–1100 °C to remove surface impurities and optimize the lattice structure. Ammonia gas (NH3) is introduced for surface nitridation in the temperature range of 800–1100 °C to enhance the bonding ability between the surface of the substrate 101 and GaN.
[0067] S102, removing the substrate, and forming a diamond layer on the first surface of the non-polar gallium nitride layer, where the first surface is the surface of the non-polar gallium nitride layer after removing the substrate.
[0068] In the embodiment of the present application, after forming the non-polar gallium nitride layer 120 on the substrate 101, the substrate 101 can be removed. The non-polar gallium nitride layer 120 after removing the substrate 101 has a first surface and a second surface arranged oppositely. The first surface is the surface of the non-polar gallium nitride layer 120 after removing the substrate 101. A diamond layer 110 can be formed on the first surface of the non-polar gallium nitride layer 120, as shown in Figure 6 shown.
[0069] As a possible implementation, after forming the non-polar gallium nitride layer 120 on the substrate 101, the substrate 101 can be removed by one or more of laser lift-off, substrate 101 polishing, dry etching, or wet etching to expose the first surface of the non-polar gallium nitride layer 120.
[0070] As a possible implementation, a diamond layer 110 is formed on the first surface after the substrate 101 is removed by using a microwave plasma chemical vapor deposition (MPCVD) process. The diamond layer 110 is a polycrystalline diamond layer. The thickness of the diamond layer 110 is greater than or equal to 100 μm and less than or equal to 300 μm.
[0071] S103, form a passivation layer on the second surface of the non-polar gallium nitride layer, and the second surface is disposed opposite to the first surface.
[0072] In the embodiment of the present application, after forming the diamond layer 110, a passivation layer 130 is formed on the second surface of the non-polar gallium nitride layer 120, as shown in the reference Figure 7 shown.
[0073] As a possible implementation, the passivation layer 130 can be formed by chemical vapor deposition (CVD), atomic layer deposition (ALD), or DC sputtering process. The material of the passivation layer 130 is silicon nitride or aluminum oxide. The thickness of the passivation layer 130 is 3 - 100 nm.
[0074] S104, etch the passivation layer to the non-polar gallium nitride layer to form a first trench and a second trench, and form a first electrode and a second electrode in the first trench and the second trench respectively.
[0075] In the embodiment of the present application, after forming the passivation layer 130, the passivation layer 130 can be etched to the non-polar gallium nitride layer 120 to form a first trench and a second trench. The first trench and the second trench expose the non-polar gallium nitride layer 120, and a first electrode 141 and a second electrode 142 are formed in the first trench and the second trench respectively, as shown in the reference Figure 1 shown.
[0076] As a possible implementation, the extending directions of the first trench and the second trench are the polar directions of the non-polar gallium nitride layer 120, so that the extending directions of the formed first electrode 141 and the second electrode 142 are also the polar directions of the non-polar gallium nitride layer 120.
[0077] As a possible implementation, the first electrode 141 is a Schottky contact electrode, the second electrode 142 is an ohmic contact electrode, the first electrode 141 is an anode, and the second electrode 142 is a cathode, that is, the Schottky contact electrode is an anode and the ohmic contact electrode is a cathode. The non-polar gallium nitride device provided in the present application is a gallium nitride-based Schottky diode.
[0078] As a possible implementation, the material of the first electrode 141 or the second electrode 142 can be one or more of titanium, aluminum, nickel, platinum, and gold.
[0079] The first electrode 141 can also be a laminated structure, and the laminated structure is a nickel-gold laminate or a platinum-gold laminate.
[0080] As an example, the depths of the first trench and the second trench are 100 nm, and the heights of the first electrode 141 and the second electrode 142 are at least greater than 100 nm.
[0081] It can be seen that in the method for manufacturing a non-polar gallium nitride layer provided by the embodiments of the present application, an r-plane or m-plane sapphire substrate with a [11-20] crystal orientation is selected, and it is first subjected to heat treatment and ammonia nitridation treatment to improve the surface quality; the substrate is removed, and after an N-type doped non-polar GaN layer is epitaxially grown on the substrate, the substrate is removed; a high-thermal-conductivity diamond layer is grown on the substrate removal surface of the GaN layer by microwave plasma chemical vapor deposition to enhance the heat dissipation capacity; subsequently, a passivation layer is grown on the non-substrate removal surface of the non-polar GaN layer and openings are formed to form anode and cathode metal electrodes. By introducing a diamond-non-polar GaN heterointerface structure with a low interface state density, the present application reduces the radio frequency loss of the device and improves the heat dissipation performance, and is applicable to the preparation and application of high-power high-frequency gallium nitride devices.
[0082] Each embodiment in this specification is described in a progressive manner. The same or similar parts among the embodiments can be referred to each other, and the key point of each embodiment is to illustrate the differences from other embodiments. In particular, for the method embodiments, since they are basically similar to the structure embodiments, the description is relatively simple, and the relevant parts can refer to the partial description of the structure embodiments.
[0083] The above are only the preferred embodiments of the present application. Although the present application has been disclosed above with preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solution of the present application, or modify it into an equivalent embodiment with equivalent changes, without departing from the scope of the technical solution of the present application. Therefore, any simple modification, equivalent change, and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the protection of the technical solution of the present application.
Claims
1. A non-polar gallium nitride device, characterized in that, The non-polar gallium nitride device includes a diamond layer, a non-polar gallium nitride layer, a passivation layer, a first electrode, and a second electrode that are sequentially stacked; A heterointerface is formed between the diamond layer and the non-polar gallium nitride layer, and the interface state concentration of the heterointerface satisfies the low interface state concentration condition; The first electrode and the second electrode penetrate through the passivation layer to the non-polar gallium nitride layer.
2. The non-polar gallium nitride device according to claim 1, wherein The non-polar gallium nitride layer is an m-plane gallium nitride layer or an a-plane gallium nitride layer; A heterointerface is formed between the diamond layer and the m-plane gallium nitride layer, or a heterointerface is formed between the diamond layer and the a-plane gallium nitride layer.
3. The non-polar gallium nitride device according to claim 1, wherein The diamond layer is a polycrystalline diamond layer.
4. The non-polar gallium nitride device according to claim 1, wherein The non-polar gallium nitride layer is an N-type doped non-polar gallium nitride layer.
5. The non-polar gallium nitride device according to claim 1, wherein The direction in which the first electrode and the second electrode penetrate through the passivation layer is the polar direction of the non-polar gallium nitride layer.
6. The non-polar gallium nitride device according to claim 1, wherein The material of the passivation layer is silicon nitride or aluminum oxide.
7. The non-polar gallium nitride device according to claim 1, wherein The first electrode is a Schottky contact electrode, and the second electrode is an ohmic contact electrode.
8. The non-polar gallium nitride device according to claim 7, characterized in that The first electrode is a stacked structure, and the stacked structure is a nickel-gold stack or a platinum-gold stack.
9. A manufacturing method of a non-polar gallium nitride device, characterized in that, The method includes: Forming a non-polar gallium nitride layer on a substrate; Removing the substrate, and forming a diamond layer on a first surface of the non-polar gallium nitride layer, where the first surface is the surface of the non-polar gallium nitride layer after removing the substrate; Forming a passivation layer on a second surface of the non-polar gallium nitride layer, where the second surface and the first surface are oppositely arranged; Etching the passivation layer to the non-polar gallium nitride layer to form a first trench and a second trench, and forming a first electrode and a second electrode in the first trench and the second trench respectively.
10. The method according to claim 9, wherein Before forming the non-polar gallium nitride layer on the substrate, the method further includes: Performing a heat treatment on the substrate; Performing a nitridation treatment on the heat-treated substrate.