Gallium nitride element, method for manufacturing a gallium nitride element, and electronic device

Abstract

The embodiments of the present application disclose a gallium nitride device, a method for manufacturing the gallium nitride device, and an electronic device. The gallium nitride device may include a gallium nitride layer, a barrier layer on a surface of the gallium nitride layer, and a gate on the side of the barrier layer away from the gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. The elements of the constituent material of the barrier layer include aluminum (Al), gallium (Ga), and nitrogen (N). The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region, and the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases in the direction of the gate region away from the gallium nitride layer, and based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, so that the electrons at the AlGaN / GaN interface in the gate region can be naturally depleted, and the two-dimensional electron gas channel in the non-gated region is not depleted. In addition, when a normally closed gallium nitride device is formed, no defect state is formed in the barrier layer in the non-gated region due to Mg doping. Therefore, the risk of degradation of the dynamic resistance of the device and the resistance degradation after HTOL is reduced, and a gallium nitride device with excellent performance is obtained.

Description

[Technical Field]

[0001] This application relates to the field of semiconductor manufacturing technology, and in particular to gallium nitride devices, gallium nitride device and electronic devices. [Background technology]

[0002] With the development of power supply products towards higher efficiency and smaller size, gallium nitride devices such as power switches, which are fabricated based on the wide bandgap semiconductor material gallium nitride (GaN), are gaining increasing interest.

[0003] Currently, gallium nitride devices primarily include devices with aluminum gallium nitride (AlGaN) / GaN heterostructures, such as high electron mobility transistors (HEMTs). AlGaN / GaN heterostructures naturally form a high-mobility two-dimensional electron gas (2-DEG) channel at the AlGaN / GaN interface. Therefore, devices fabricated based on the heterostructure are normally open switch-type devices. However, in the application field of switching power supplies, normally closed gallium nitride devices have advantages such as a compatible Si device drive system and simple drive mode, making them more commercially viable.

[0004] In the fabrication process of normally closed gallium nitride devices, a p-type GaN (p-GaN) layer is grown on the surface of an AlGaN / GaN heterostructure in the gate region. The p-GaN layer is doped with magnesium (Mg) during the epitaxial growth process to deplete the two-dimensional electron gas channel, preventing the formation of p-GaN in the non-gated region outside the gate region. In this way, the gate region does not have a channel, while the non-gated region does. However, current p-GaN-based normally closed gallium nitride devices have reliability issues, such as severe degradation of dynamic resistance and resistance degradation after high-temperature operating lifetime (HTOL) testing. Summary of the Invention

[0005] In consideration of this, embodiments of the present application provide a gallium nitride element, a method for fabricating a gallium nitride element, and an electronic device to implement channel depletion by forming a new structure in the gate region, thereby reducing the risk of degradation in dynamic resistance and degradation in resistance after HTOL. [Means for solving the problem]

[0006] According to a first aspect of an embodiment of the present application, there is provided a gallium nitride device including a gallium nitride layer, a barrier layer on a surface of the gallium nitride layer side, and a gate on the side of the barrier layer away from the gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. The barrier layer is made of aluminum (Al), gallium (Ga), and nitrogen (N). The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region, and the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases toward the gate region away from the gallium nitride layer. Based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, which allows electrons at the AlGaN / GaN interface in the gate region to be naturally depleted, while the two-dimensional electron gas channel in the non-gated region is not depleted. In addition, when a normally closed gallium nitride device is formed, the Mg doping prevents the formation of defect states in the barrier layer in the non-gated region. This reduces the risk of degradation of the device's dynamic resistance and resistance degradation after HTOL, resulting in a gallium nitride device with superior performance.

[0007] In some possible implementations, the barrier layer includes a first portion facing the gallium nitride layer and a second portion facing the gate, the first portion having a higher aluminum concentration than the second portion, the first portion being located in the gate region and the non-gated region, and a protrusion of the second portion above the surface of the gallium nitride layer being located in the gate region.

[0008] In this embodiment of the present application, the barrier layer may include a first portion and a second portion. The aluminum concentration of the first portion is higher than the aluminum concentration of the second portion, and the second portion is located on the first portion of the gate region. The first portion and the second portion of the gate region may naturally correspond to p-type doping without Mg doping. This facilitates channel depletion in the gate region.

[0009] In some possible implementations, the first portion is a first film layer and the second portion includes multiple stacked sub-film layers, and the aluminum concentration of the sub-film layer facing the gate is lower than the aluminum concentration of the sub-film layer facing the first portion.

[0010] In this embodiment of the present application, the barrier layer can have a multi-layer structure, where the first part is a first film layer and the second part includes multiple stacked sub-film layers so that the concentration of the barrier layer decreases sequentially, which enhances the polarization effect of the barrier layer in the gate region and facilitates aluminum concentration control and channel depletion in the gate region.

[0011] In some possible embodiments, the aluminum concentration of the second portion exhibits a decreasing trend from the side facing the first portion to the side facing away from the first portion.

[0012] In this embodiment of the present application, the second portion may be a monolithic structure. The monolithic structure does not have a clear boundary, and the aluminum concentration therein tends to decrease from the side facing the first portion to the side away from the first portion so that the aluminum concentration is gradually arranged. This enhances the polarization effect of the barrier layer in the gate region and facilitates aluminum concentration control and channel depletion in the gate region.

[0013] In some possible embodiments, the size of the barrier layer located in the non-gated region in the direction perpendicular to the surface of the gallium nitride layer is 30 nm or less.

[0014] In the embodiment of the present application, the thickness of the barrier layer in the non-gated region is small, which allows two-dimensional electron gas to be generated, and the thickness of the barrier layer in the gated region is also small, which facilitates channel depletion in the gated region.

[0015] In some possible embodiments, the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is 3 / 7 or greater.

[0016] In this embodiment of the present application, the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is equal to or greater than a predetermined value so that the barrier layer in the non-gated region has a high aluminum concentration, which helps to generate sufficient two-dimensional electron gas between the barrier layer and the aluminum gallium nitride layer and form a channel in the non-gated region.

[0017] In some possible embodiments, the gallium nitride device comprises: a source and a drain located on a side of the barrier layer in the non-gated region away from the gallium nitride layer; Further includes:

[0018] In this embodiment of the present application, the gallium nitride device further includes a source and a drain located on either side of the gate, respectively, and configured to apply a source signal and a drain signal.

[0019] In some possible implementations, the material of at least one of the source, drain, and gate is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

[0020] In this embodiment of the present application, the source, drain and gate materials are relatively conductive materials, which helps to improve the performance of the device.

[0021] In some possible embodiments, the gallium nitride device comprises: a passivation layer, the passivation layer covering the barrier layer located in the non-gated region; Further includes:

[0022] In this embodiment of the present application, the gallium nitride device further includes a passivation layer configured to provide stress to the barrier layer and promote the regeneration of a two-dimensional electron gas channel in the ungated region, which helps to obtain a channel with a high charge transfer rate.

[0023] In some possible implementations, the passivation layer further covers the barrier layer located in the gate region, and the gate includes an electrically connected first gate structure and a second gate structure, the first gate structure penetrating the passivation layer, and the second gate structure formed on the side of the first gate structure away from the gallium nitride layer and covering a portion of the surface of the passivation layer.

[0024] In an embodiment of the present application, the gate may include two portions to form a "T" shaped structure to facilitate withdrawal from the gate.

[0025] In some possible implementations, the material of the passivation layer is at least one of silicon nitride and aluminum carbide.

[0026] In this embodiment of the present application, the passivation layer is a material that can provide stress to the barrier layer, facilitating channel regeneration in the ungated region.

[0027] In some possible embodiments, the gallium nitride device comprises: a gate dielectric layer located between the barrier layer and the gate; Further includes:

[0028] In this embodiment of the present application, there may be a gate dielectric layer between the barrier layer and the gate, which reduces interface defects and improves the threshold stability of the device compared to direct contact between the gate and the barrier layer.

[0029] In some possible embodiments, the gallium nitride device comprises: a substrate on the side of the gallium nitride layer away from the barrier layer; Further includes:

[0030] In this embodiment of the present application, the gallium nitride layer may be disposed on a substrate, and the substrate is used to provide support for the gallium nitride layer.

[0031] In some possible embodiments, the gallium nitride device comprises: a buffer layer positioned between the substrate and the gallium nitride layer; Further includes:

[0032] In this embodiment of the present application, a buffer layer is formed between the gallium nitride layer and the substrate, which facilitates forming a gallium nitride layer with good quality.

[0033] A second aspect of an embodiment of the present application is a method for manufacturing a gallium nitride device, comprising: obtaining a gallium nitride layer, the gallium nitride layer having a gate region and a non-gated region outside the gate region; forming a barrier layer on the surface on the gallium nitride layer side and a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer, wherein the elements of the constituent material of the barrier layer include aluminum, gallium, and nitrogen, the barrier layer is located in the gate region and the non-gated region, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region in a direction perpendicular to the surface of the gallium nitride layer, and the aluminum concentration of the barrier layer located in the gate region on the side facing the gallium nitride layer is higher than the aluminum concentration of the barrier layer located in the gate region on the side facing the gate; The present invention provides a method comprising:

[0034] In some possible implementations, the barrier layer includes a first portion facing the gallium nitride layer and a second portion facing the gate, the first portion having a higher aluminum concentration than the second portion, the first portion being located in the gate region and the non-gated region, and a protrusion of the second portion above the surface of the gallium nitride layer being located in the gate region.

[0035] In some possible implementations, the first portion is a first film layer and the second portion includes multiple stacked sub-film layers, and the aluminum concentration of the sub-film layer facing the gate is lower than the aluminum concentration of the sub-film layer facing the first portion.

[0036] In some possible embodiments, the aluminum concentration of the second portion exhibits a decreasing trend from the side facing the first portion to the side facing away from the first portion.

[0037] In some possible embodiments, the size of the barrier layer located in the non-gated region in the direction perpendicular to the surface of the gallium nitride layer is 30 nm or less.

[0038] In some possible embodiments, the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is 3 / 7 or greater.

[0039] In some possible embodiments, the method comprises: forming a source and a drain on the side of the barrier layer in the non-gated region away from the gallium nitride layer; Further includes:

[0040] In some possible implementations, the material of at least one of the source, drain, and gate is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

[0041] In some possible implementations, the step of forming a barrier layer on the surface on the side of the gallium nitride layer and a gate located on the side of the barrier layer in the gate region away from the gallium nitride layer comprises: forming an aluminum gallium nitride material layer on the surface of the gallium nitride layer side, the aluminum gallium nitride material layer being composed of elements including aluminum, gallium, and nitrogen, and the aluminum concentration of the aluminum gallium nitride material layer on the side facing the gallium nitride layer being higher than the aluminum concentration of the aluminum gallium nitride material layer on the side away from the gallium nitride layer; thinning the layer of aluminum gallium nitride material located in the non-gated area to obtain a barrier layer; forming a gate on a side of the barrier layer located in the gate region away from the gallium nitride layer; Includes:

[0042] In some possible implementations, the step of forming a gate on a side of the barrier layer located in the gate region away from the gallium nitride layer comprises: forming a passivation layer overlying the barrier layer; etching the passivation layer covering the barrier layer in the gate region to form a gate hole through the passivation layer, and forming a gate in the gate hole; Includes:

[0043] In some possible implementations, the gate includes a first gate structure and a second gate structure electrically connected together, the first gate structure being located in the gate hole, and the second gate structure being formed on a side of the first gate structure away from the gallium nitride layer and covering a portion of the surface of the passivation layer.

[0044] In some possible implementations, prior to the step of forming the gate, the method further comprises: forming a gate dielectric layer between the barrier layer and the gate; Further includes:

[0045] In some possible implementations, the step of forming a barrier layer on the surface on the side of the gallium nitride layer and a gate located on the side of the barrier layer in the gate region away from the gallium nitride layer comprises: forming an aluminum gallium nitride material layer on the surface of the gallium nitride layer side and a gate material layer located on a side of the aluminum gallium nitride material layer remote from the gallium nitride layer, wherein the constituent elements of the aluminum gallium nitride material layer include aluminum, gallium, and nitrogen, and the aluminum concentration of the side of the aluminum gallium nitride material layer facing the gallium nitride layer is higher than the aluminum concentration of the side of the aluminum gallium nitride material layer remote from the gallium nitride layer; etching the gate material layer located on a side of the aluminum gallium nitride material layer away from the gallium nitride layer in the non-gated regions to thin the aluminum gallium nitride material layer in the non-gated regions to obtain a barrier layer and a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer; Includes:

[0046] In some possible implementations, the method includes forming a gate intermediate material layer between the aluminum gallium nitride material layer and the gate material layer; a gate intermediate material layer located on a side of the aluminum gallium nitride material layer in the non-gated region away from the gallium nitride layer is further etched to obtain a gate dielectric layer located between the barrier layer and the gate when the gate material layer located on a side of the aluminum gallium nitride material layer in the non-gated region away from the gallium nitride layer is etched and the aluminum gallium nitride material layer in the non-gated region is thinned; Further includes:

[0047] In some possible embodiments, after the step of forming the barrier layer, the method further comprises: forming a passivation layer overlying the barrier layer; Further includes:

[0048] In some possible implementations, the material of the passivation layer is at least one of silicon nitride and aluminum carbide.

[0049] In some possible implementations, the substrate is positioned on the side of the gallium nitride layer away from the barrier layer.

[0050] In some possible implementations, a buffer layer is disposed between the gallium nitride layer and the substrate.

[0051] According to a third aspect of an embodiment of the present application, there is provided an electronic device including a circuit board and a gallium nitride device provided in the first aspect of the present application connected to the circuit board.

[0052] According to the above technical solutions, it can be seen that the embodiments of the present application have the following advantages:

[0053] Embodiments of the present application provide a gallium nitride device, a method for manufacturing the gallium nitride device, and an electronic device. The gallium nitride device may include a gallium nitride layer, a barrier layer on a surface of the gallium nitride layer side, and a gate on the side of the barrier layer away from the gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. The constituent elements of the barrier layer include aluminum (Al), gallium (Ga), and nitrogen (N). The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region, and the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases toward the gate region away from the gallium nitride layer. Based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, which allows electrons at the AlGaN / GaN interface in the gate region to be naturally depleted, while the two-dimensional electron gas channel in the non-gated region is not depleted. In addition, when a normally closed gallium nitride device is formed, the Mg doping prevents the formation of defect states in the barrier layer in the non-gated region. This reduces the risk of degradation of the device's dynamic resistance and resistance degradation after HTOL, resulting in a gallium nitride device with superior performance.

[0054] To clearly understand the specific embodiments of the present application, the following briefly describes the accompanying drawings used to illustrate the specific embodiments of the present application. Obviously, the accompanying drawings only illustrate some embodiments of the present application. [Brief explanation of the drawings]

[0055] [Figure 1] FIG. 1 is a schematic diagram of the epitaxial growth of a p-GaN layer according to an embodiment of the present application. [Figure 2] FIG. 2 is a schematic diagram of forming a p-GaN layer in the gate region according to an embodiment of the present application. [Figure 3] FIG. 1 is a schematic diagram of the correlation between dynamic resistance and Mg doping concentration of a device according to an embodiment of the present application. [Figure 4] 1 is a schematic diagram of a structure of a gallium nitride device according to an embodiment of the present application. [Figure 5] FIG. 2 is a schematic diagram of the structure of the second portion according to an embodiment of the present application. [Figure 6] FIG. 2 is a schematic diagram of concentration distributions of a first portion and a second portion according to an embodiment of the present application; [Figure 7] FIG. 2 is a schematic diagram of the barrier height of the gallium nitride layer and the barrier layer in the gate region according to an embodiment of the present application. [Figure 8] 2 is a schematic diagram of another gallium nitride device structure according to an embodiment of the present application. [Figure 9] 1 is a schematic diagram of yet another gallium nitride device structure according to an embodiment of the present application. [Figure 10] 2 is a schematic diagram of yet another gallium nitride device structure according to an embodiment of the present application. [Figure 11] 1 is a flowchart of a method for manufacturing a gallium nitride device according to an embodiment of the present application. [Figure 12] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 13] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 14] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 15] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 16] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 17] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 18]1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 19] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 20] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. [Figure 21] 1A-1C are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0056] Embodiments of the present application provide a gallium nitride element, a method for fabricating a gallium nitride element, and an electronic device to implement channel depletion by forming a new structure in the gate region, thereby reducing the risk of dynamic resistance degradation and post-HTOL resistance degradation.

[0057] In the specification, claims, and accompanying drawings of this application, terms such as "first," "second," "third," and "fourth," when present, are intended to distinguish between similar objects, but do not necessarily denote a particular order or sequence. References in this manner should be understood to be interchangeable, where appropriate, such that the embodiments described herein can be performed in other orders other than those illustrated or described herein. Additionally, the terms "comprise" and "have," as well as any other variations thereof, are intended to refer to a non-exclusive inclusion. For example, a process, method, system, product, or device that includes a list of steps or units is not necessarily limited to those explicitly listed steps or units and may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or device.

[0058] The present application will be described in detail with reference to schematic drawings. For ease of explanation, when the embodiments of the present application are described in detail, the cross-sectional views of the device structures are partially enlarged and not to a general scale, and the schematic drawings are merely examples and do not limit the scope of protection of the present application. In addition, the length, width, and depth of the three-dimensional space are included in the actual production.

[0059] Currently, devices fabricated based on AlGaN / GaN heterostructures are typically normally-open switch-type devices. However, normally-open GaN devices require a stable conduction current to maintain their conduction, and a reverse voltage must be applied to the gate to turn them off. This characteristic is not conducive to the design of the drive circuit and results in high device power consumption. In fact, in the application field of switching power supplies, normally-closed GaN devices have advantages such as a compatible Si device drive method and simple drive mode, making them more marketable.

[0060] In the fabrication process of normally closed gallium nitride devices, a p-GaN layer can be formed on the surface of the AlGaN / GaN heterostructure in the gate region. The p-GaN layer is doped with Mg during the epitaxial growth process to deplete the two-dimensional electron gas channel, while the non-gated region does not form p-GaN. In this way, the gated region does not have a channel, while the non-gated region does.

[0061] In a practical process, an AlGaN / GaN heterostructure is formed in both the gated and non-gated regions. In other words, both the gated and non-gated regions have two-dimensional electron gas channels. To form a p-GaN layer on the surface of the AlGaN / GaN heterostructure in the gated region, a p-GaN material layer can first be epitaxially grown on the surface of the AlGaN / GaN heterostructure in the gated and non-gated regions. FIG. 1 is a schematic diagram of the epitaxial growth of a p-GaN layer according to one embodiment of the present application. An aluminum gallium nitride layer 120 is formed on a gallium nitride layer 110, and a two-dimensional electron gas (not shown) is formed between the gallium nitride layer 110 and the aluminum gallium nitride layer 120. A p-GaN material layer 130 is epitaxially grown on the aluminum gallium nitride layer 120, and Mg is doped into the p-GaN material layer 130. Next, the p-GaN material layer in the non-gated region is etched to restore the two-dimensional electron gas channel in the non-gated region, forming a p-GaN layer 131 located in the gated region. 2 is a schematic diagram of forming a p-GaN layer in the gate region according to one embodiment of the present application. Next, a gate 141 can be formed on the p-GaN layer 131, and a source 142 and a drain 143 can be formed in the non-gated region. Meanwhile, during the epitaxial growth process, Mg atoms used to form the p-GaN also diffuse (out-diffuse) into the AlGaN barrier layer (i.e., the aluminum gallium nitride layer 120), introducing defect energy levels into the aluminum gallium nitride layer 120. This causes electrons to be trapped by these defect energy levels during the high-voltage switching process of the device, as shown in FIGS. 1 and 2. As a result, reliability issues such as degradation of the device's dynamic resistance and post-HTOL resistance can occur.

[0062] The degradation of the dynamic resistance of the device is strongly related to the Mg doping concentration. A higher Mg doping concentration in p-GaN indicates a more severe degradation of the dynamic resistance of the device. Figure 3 is a schematic diagram of the correlation between the dynamic resistance of the device and the Mg doping concentration according to one embodiment of the present application. The horizontal coordinate is the Mg doping concentration, and the vertical coordinate is the dynamic resistance of the device. From the diagram, it can be seen that a higher Mg doping concentration indicates a more severe degradation of the dynamic resistance of the device. Although the degradation of the dynamic resistance can be reduced by reducing the Mg concentration, the threshold voltage of the device also decreases accordingly, which is unfavorable for switch application scenarios. Therefore, how to implement depletion of the two-dimensional electron gas channel in the gate region without affecting the dynamic resistance of the device is an urgent problem to be solved in this field.

[0063] To solve the aforementioned technical problems, embodiments of the present application provide a gallium nitride device, a method for manufacturing the gallium nitride device, and an electronic device. The gallium nitride device may include a gallium nitride layer, a barrier layer on a surface of the gallium nitride layer side, and a gate on the side of the barrier layer away from the gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. The barrier layer is made of aluminum, gallium, and nitrogen. The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region, and the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases toward the gate region away from the gallium nitride layer. Based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, which allows electrons at the AlGaN / GaN interface in the gate region to be naturally depleted, while the two-dimensional electron gas channel in the non-gated region is not depleted. In addition, when a normally closed gallium nitride device is formed, the Mg doping prevents the formation of defect states in the barrier layer in the non-gated region. This reduces the risk of degradation of the device's dynamic resistance and resistance degradation after HTOL, resulting in a gallium nitride device with superior performance.

[0064] To make the objects, features, and advantages of the present application more clear and understandable, the following describes in detail certain embodiments of the present application with reference to the accompanying drawings.

[0065] 4 is a schematic diagram of the structure of a gallium nitride device according to one embodiment of the present application. The gallium nitride device includes a gallium nitride layer 220, barrier layers 231 & 232, and a gate 251. The barrier layers 231 & 232 are located on the surface of the gallium nitride layer 220, and the constituent materials of the barrier layers 231 & 232 include aluminum, gallium, and nitrogen. The constituent materials of the barrier layers 231 & 232 are aluminum gallium nitride (Al x Ga 1-x The gallium nitride layer 220 and the barrier layers 231 & 232, whose material is aluminum gallium nitride, form an AlGaN / GaN heterostructure, generating two-dimensional electron gas. Based on this, a gallium nitride device can operate using the two-dimensional electron gas generated by the heterostructure. The gallium nitride device can be, for example, a gallium nitride-based high electron mobility transistor (HEMT) device.

[0066] In a possible embodiment, the thickness of the gallium nitride layer 220 may be greater. In this case, the gallium nitride layer 220 may be a substrate, the material of which is gallium nitride. The substrate provides a support function for the membrane layers on the substrate and is also used as an element of the AlGaN / GaN heterostructure.

[0067] In another possible embodiment, the gallium nitride layer 220 may be thin. In this case, the gallium nitride layer 220 may be formed on a substrate 200. The substrate 200 is disposed on the side of the gallium nitride layer away from the barrier layers 231 and 232. The substrate 200 provides a support function for the film layers on the substrate 200. The gallium nitride layer 220 is used as an element of an AlGaN / GaN heterostructure, and the material of the substrate 200 may be one or more of aluminum nitride (AlN), silicon (Si), silicon carbide (SiC), and sapphire. Optionally, a buffer layer 210 may be further disposed between the substrate 200 and the gallium nitride layer 220. The material of the buffer layer 210 may be aluminum nitride or low-temperature grown gallium nitride. When the buffer layer 210 is low-temperature grown gallium nitride, the gallium nitride layer 220 may be high-temperature grown gallium nitride. In this manner, the low temperature gallium nitride layer is used as a buffer layer 210 between the high temperature gallium nitride layer and the substrate 200 to improve the epitaxial quality of the high temperature gallium nitride layer.

[0068] The gallium nitride layer 220 may have a gate region 1001 and a non-gated region 1002 outside the gate region 1001. The gate region 1001 and the non-gated region 1002 are regions on the surface of the gallium nitride layer 220 and include a space defined by the surface of the gallium nitride layer 220 and a number of straight lines perpendicular to the gallium nitride layer 220. For ease of explanation, the direction parallel to the surface of the gallium nitride layer 220 is used as the horizontal direction, and the direction perpendicular to the surface of the gallium nitride layer 220 is used as the vertical direction. The gate region 1001 is used to form the gate 251 and may be the central region between the regions in which the source 252 and the drain 253 are located. The gate region 1001 may be larger than the region in which the gate 251 is located or may be equal to the region in which the gate 251 is located. In Figure 4, the dashed box in the middle represents the gate region 1001, and the dashed boxes on either side of the gate region 1001 represent the non-gated regions 1002. The same representation will be used in subsequent schematic diagrams of the structure. Because Figure 4 is a cross-sectional view, in practice the non-gated regions 1002 may be located on either side of the gate region 1001, or may be located in annular regions surrounding the gate region 1001, such as an annular region or a polygonal region.

[0069] In this embodiment of the present application, the barrier layers 231 & 232 are located in the gate region 1001 and the non-gated region 1002. In a direction perpendicular to the surface of the gallium nitride layer 220 (i.e., the vertical direction), the size of the barrier layer located in the gate region 1001 is larger than the size of the barrier layer located in the non-gated region 1002. In addition, the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gate 251.

[0070] The aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gate 251. Correspondingly, the gallium concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the gallium concentration of the barrier layer in the gate region 1001 on the side facing the gate 251. Because this setting is located in the gate region 1001, the aluminum content in the gate region 1001 is reduced from the side facing the gallium nitride layer 220 to the side facing the gate 251. The portion with a lower aluminum content has a lower barrier height. Therefore, a low barrier exists between the portion with a lower aluminum content and the gallium nitride layer 220. In this structure, the aluminum content is reduced from the side facing the gallium nitride layer 220 to the side facing the gate 251. Because the polarization effect generates holes in the barrier layers 231 & 232, the barrier layers 231 & 232 of the gate region 1001 can naturally correspond to p-type doping without Mg doping, the number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 of the gate region 1001, and the electrons in the two-dimensional electron gas channel 222 can be naturally depleted.

[0071] Additionally, in the p-GaN solution, the hole concentration is strongly related to Mg activation, and therefore parameters such as the p-GaN activation temperature and doping concentration must be precisely controlled. Compared to the p-GaN solution, in this embodiment of the present application, holes are generated by the polarization effect, and the number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 of the gate region 1001. This eliminates the need for precise control of hole activation in the Mg doping technique. Additionally, the absence of a p-GaN layer eliminates the problem of defect states caused by Mg diffusion. Furthermore, the threshold voltage of the device is determined by the structure of the gate region 1001, resulting in a large process window. Therefore, the threshold voltage is not easily affected by the Mg doping concentration and p-GaN activation conditions.

[0072] Specifically, the barrier layers 231 and 232 may include a first portion 231 facing the gallium nitride layer 220 and a second portion 232 facing the gate 251. The first portion 231 is formed in the gate region 1001 and the non-gated region 1002, and the protrusion of the second portion 232 above the surface of the gallium nitride layer 220 is located in the gate region. In other words, the second portion 232 can be considered to be formed in the first portion 231 of the gate region 1001, and the second portion 232 in the gate region 1001. For ease of explanation, a subinterface is disposed between the first portion 231 and the second portion 232, and the subinterface is a plane on which the top surface of the first portion 231 is located. In the cross-sectional view of FIG. 4, the subinterface is represented as a dividing line, which is a straight line on which the top surface of the first portion 231 is located and is represented by a horizontal dashed line. In other words, the first portion 231 and the second portion 232 are separated using a horizontal dashed line. The same notation will be used in subsequent schematic diagrams of the structure. In other words, the barrier layer can be divided vertically into a first portion 231 and a second portion 232, with the second portion 232 covering the first portion 231 located in the gate region 1001. The first portion 231 and the second portion 232 are defined for ease of explanation and do not necessarily have a clear boundary. Subsequently, the first portion 231 and the second portion 232 are used to represent different portions of the barrier layer, the surface of the first portion 231 and the surface of the second portion 232 are used to represent the surface of the barrier layer, and the second portion 232 covers the surface of the first portion 231 in the gate region 1001.

[0073] The aluminum concentration in the first portion 231 is higher than the aluminum concentration in the second portion 232, and correspondingly, the gallium concentration in the first portion 231 is higher than the gallium concentration in the second portion 232. Because the second portion 232 is formed in the gate region 1001, the aluminum content in the gate region 1001 is reduced from the first portion 231 to the second portion 232. The portion with a lower aluminum content has a lower barrier height, thus resulting in a lower barrier between the portion with a lower aluminum content and the gallium nitride layer 220. In this structure, the aluminum content is reduced from the first portion 231 to the second portion 232. Because the polarization effect generates holes in the first portion 231 and the second portion 232, the barrier layers 231 & 232 of the gate region 1001 can naturally correspond to p-type doping without Mg doping, the number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 of the gate region 1001, and the electrons in the two-dimensional electron gas channel 222 can be naturally depleted.

[0074] In this embodiment of the present application, the aluminum concentration of the first portion 231 being higher than the aluminum concentration of the second portion 232 may be considered as the average aluminum concentration of the first portion 231 being higher than the average aluminum concentration of the second portion 232, and the aluminum concentration of the second portion 232 may be uniform or non-uniform.

[0075] Specifically, the second portion 232 may include multiple stacked sub-layers, where the multiple sub-layers are stacked vertically. The aluminum concentrations of the multiple sub-layers may not be identical. The aluminum concentration of the sub-layer facing the gate 251 may be lower than the aluminum concentration of the sub-layer facing the first portion. In other words, the aluminum concentration of the upper sub-layer may be lower than the aluminum concentration of the lower sub-layer. In this manner, the aluminum concentration decreases sequentially from the side facing the first portion 231 to the side away from the first portion 231. The aluminum concentration of each sub-layer exhibits a decreasing trend, thereby gradually decreasing the aluminum concentration and enhancing the polarization effect in the barrier layers 231 and 232 in the gate region 1001. For example, FIG. 5 is a schematic diagram of the structure of the second portion according to one embodiment of the present application. The second portion 232 may include n-1 stacked sub-layers. In addition, the first portion 231 may be a first layer (not shown in FIG. 5). Specifically, the barrier layers 231 and 232 of the gate region 1001 include a total of n film layers, where n≧2. The components of the first portion 231 are Al x1 Ga 1-x1 N. From the side facing the first portion 231 to the side away from the first portion 231, the composition of the sub-film layer is Al x2 Ga 1-x2 N, Al x3 Ga 1-x3 N, Al x4 Ga 1-x4 N, …, Al xn Ga 1-xn N, where 1≧x1>x2≧x3 ...≧xn≧0. When x1=1, the material of the corresponding first portion 231 is AlN. When xn=0, the material of the corresponding sub-layer is GaN.

[0076] 6 is a schematic diagram of the concentration distribution of the first and second portions according to one embodiment of the present application. The horizontal coordinate represents the height of the film layer. The interface between the first portion 231 and the gallium nitride layer 220 is used as the height zero, and the height of the film layer gradually increases from the side facing the first portion 231 to the side away from the first portion 231. The vertical coordinate represents the content of the Al component. 6A inAs shown in Figure 1, the aluminum content at different film layer heights within each sub-film layer is the same. From the side facing the first portion 231 to the side away from the first portion 231, the aluminum content gradually decreases, which is represented by the gradual decrease of x1, x2, x3, x4, ..., and xn. Of course, from the side facing the first portion 231 to the side away from the first portion 231, the aluminum concentration in the multiple sub-film layers does not have to decrease strictly sequentially. Instead, the aluminum concentration in a few sub-film layers may be slightly increased. In other words, the aluminum concentration in some upper sub-film layers may be higher than the aluminum concentration in the lower sub-film layers.

[0077] Since a portion with a lower aluminum content has a lower barrier height, the barrier height of the second portion 232 gradually decreases from the side facing the first portion 231 to the side away from the first portion 231. When the second portion 232 includes multiple sub-layers stacked vertically, and the aluminum concentration of the multiple sub-layers gradually decreases, the barrier height of the second portion 232 also gradually decreases. FIG. 7 is a schematic diagram of the barrier heights of the gallium nitride layer and barrier layer in the gate region according to an embodiment of the present application. An example where n is 6 is used for illustration, and x6=0. The gallium nitride layer (GaN) 220, the first portion (Al x1 Ga 1-x1 N)231, and a second portion (Al x2 Ga 1-x2 N, Al x3 Ga 1-x3 N, Al x4 Ga 1-x4 N, Al x5 Ga 1-x5 N, GaN)232 are arranged sequentially from right to left, and Al x1 Ga 1-x1 N, Al x2 Ga 1-x2 N, Al x3 Ga 1-x3 N, Al x4 Ga 1-x4 N, and Al x5 Ga 1-x5The barrier height of the second portion 232 decreases from right to left. Thus, the number of holes generated on the side of the first portion 231 away from the gallium nitride layer 220 is σ p1 The number of holes generated in the second portion 232 is expressed as σ p2 , σ p3 , σ p4 , σ p5 , and σ p6 and σ p1 , σ p2 , σ p3 , σ p4 , σ p5 , and σ p6 The number of holes generated in the barrier layers 231 and 232 of the gate region 1001, σ n is σ p1 , σ p2 , σ p3 , σ p4 , σ p5 , and σ p6 The first part (Al x1 Ga 1-x1 The number of electrons generated between the gate region 1001 and the gallium nitride (GaN) layer 220 is essentially the same as the number of electrons located in the two-dimensional electron gas channel 222 of the gate region 1001.

[0078] Specifically, second portion 232 may instead be a monolithic structure without a clear boundary, i.e., there may not be a clear, abrupt change in the aluminum content of second portion 232, but rather the aluminum concentration of second portion 232 may exhibit a downward trend from the side facing first portion 231 to the side away from first portion 231. The downward trend may be a continuous and uniform decrease, or may be an uneven decrease. 6B inAs shown in FIG. 1, the aluminum concentration at different film layer heights within the first portion 231 is the same, and the aluminum concentration of the second portion 232 decreases at a uniform rate from the side facing the first portion 231 to the side away from the first portion 231. Of course, the aluminum concentration of the second portion 232 may also increase slightly at a few positions between the side facing the first portion 231 and the side away from the first portion 231. In addition, the first portion 231 and the second portion 232 may instead be an integral structure without a clear boundary, and the aluminum in the first portion 231 is uniformly distributed.

[0079] In this embodiment of the present application, the molar ratio of aluminum to gallium in the barrier layer located in the non-gate region is 3 / 7 or more. In other words, the molar ratio of aluminum to gallium in the first portion 231 is 3 / 7 or more, i.e., x1≧30%. Therefore, the first portion 231 has a high barrier height and can effectively generate two-dimensional electron gas.

[0080] In this embodiment of the present application, the two-dimensional electron gas channel 222 generated between the aluminum gallium nitride layer and the gallium nitride layer 220, which has a low thickness, is easily depleted. Therefore, the first portion 231 may be set to have a small thickness. Specifically, the size (i.e., vertical size) of the first portion 231 in a direction perpendicular to the surface of the gallium nitride layer 220 (i.e., the barrier layer in the non-gated region 1002) may be 30 nm or less, for example, 5 nm. When the vertical size of the first portion 231 is small, the passivation layer 240 may be formed on the surface of the first portion 231 (i.e., the barrier layer in the non-gated region 1002) to generate stress. 10024, a passivation layer 240 may be further formed on the barrier layer of the gate region 1001 (i.e., the surface of the barrier layer of the gate region 1001), thereby regenerating the two-dimensional electron gas channel 222 in the first portion 231, as shown in FIG. 4, which helps to implement a channel with a high charge transfer rate. The passivation layer 240 may cover the barrier layer of the non-gated region 1002 (i.e., the first portion 231) and further cover the barrier layer of the gate region 1001 (i.e., the second portion 232). For example, the second portion 232 covers the first portion 231 of the gate region 1001 and covers the sidewalls of the second portion 232. The passivation layer 240 may further cover a portion of the top surface of the second portion 232. The material of the passivation layer 240 may be at least one of silicon nitride and aluminum carbide.

[0081] In this embodiment of the present application, the gate 251 is formed on the side of the barrier layers 231 & 232 of the gate region 1001 away from the gallium nitride layer 220 , ie, on the second portion 232 .

[0082] In some possible implementations, as shown in FIG. 4 , a portion of the top surface of second portion 232 may be covered with passivation layer 240, and gate 251 may penetrate passivation layer 240 covering second portion 232. In some possible implementations, gate 251 may include an electrically connected first gate structure and a second gate structure, where the first gate structure penetrates passivation layer 240 and the second gate structure is formed on the side of the first gate structure away from substrate 200 and covers a portion of the surface of passivation layer 240. In other words, gate 251 may form a “T”-shaped structure. As shown in FIG. 4 , gate 251 may cover a portion of the top surface of second portion 232 and a portion of the top surface of passivation layer 240 so that gate 251 can be easily pulled out.

[0083] In some other possible implementations, gate 251 may instead cover the entire top surface of second portion 232 to form a surface-like structure, and the sidewalls of gate 251 and second portion 232 may be flush. Figure 8 is a schematic diagram of another gallium nitride device structure according to an embodiment of the present application. A passivation layer may cover the sidewalls of gate 251.

[0084] In this embodiment of the present application, the gate 251 may be in direct contact with the second portion 232 to form a Schottky gate element structure. As shown in Figures 4 and 8, compared to the solution in which the gate 251 is in contact with the first portion 231, the solution in which the gate 251 is in contact with the second portion 232 reduces the forward leakage current of the device.

[0085] In this embodiment of the present application, a gate dielectric layer 260 may also be formed between the gate 251 and the second portion 232 of the barrier layer to form an insulated gate element structure. Compared to a solution in which the gate 251 contacts the first portion 231 having a higher aluminum concentration and the gate dielectric layer 260 directly contacts the first portion 231 having a higher aluminum concentration, the solution in which the gate 251 contacts the gate dielectric layer 260 and the gate dielectric layer 260 contacts the second portion 232 reduces interface defects and improves the threshold stability of the device.

[0086] In some possible implementations, FIG. 9 is a schematic diagram of yet another gallium nitride device structure according to an embodiment of the present application. FIG. 9 is a schematic diagram of a gallium nitride structure obtained after a gate dielectric layer 260 is added based on the gallium nitride structure of FIG. 4. The gate 251 includes an electrically connected first gate structure and a second gate structure, and the gate dielectric layer 260 is formed between the gate 251 and the second portion 232 to cover a portion of the top surface of the second portion 232. The gate dielectric layer 260 may further be formed between the gate 251 and the passivation layer 240 to cover a sidewall of the passivation layer 240 facing the gate 251. Of course, the gate dielectric layer 260 may also cover a sidewall of the passivation layer 240 away from the gate 251 and cover a portion of the surface of the first portion 231.

[0087] In some other possible implementations, Figure 10 is a schematic diagram of yet another gallium nitride device structure according to an embodiment of the present application. Figure 10 is a schematic diagram of the resulting gallium nitride structure after a gate dielectric layer 260 is added based on the gallium nitride structure of Figure 8. The gate dielectric layer 260 covers the entire top surface of the second portion 232, and the gate 251 covers the entire top surface of the gate dielectric layer 260. The passivation layer 240 may cover the sidewalls of the gate dielectric layer 260 and may also cover the sidewalls of the gate 251.

[0088] In this embodiment of the present application, the gallium nitride device may further include a source 252 and a drain 253. The source 252 and the drain 253 are located on the side of the barrier layer of the non-gated region 1002 away from the gallium nitride layer 220, i.e., on the first portion 231. The source 252 and the drain 253 are located on both sides of the gate 251, respectively. The source 252, the drain 253, and the gate 251 are all made of materials having good electrical conductivity, and the material of at least one of the source 252, the drain 253, and the gate 251 is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

[0089] An embodiment of the present application provides a gallium nitride device. The gallium nitride device may include a gallium nitride layer, a barrier layer on the surface of the gallium nitride layer, and a gate on the side of the barrier layer away from the gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. The barrier layer is made of aluminum, gallium, and nitrogen. The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region, and the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases toward the gate region away from the gallium nitride layer, and based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, thereby naturally depleting electrons at the AlGaN / GaN interface in the gate region and not depleting the two-dimensional electron gas channel in the non-gated region. In addition, when forming normally closed gallium nitride devices, the Mg doping prevents the formation of defect states in the barrier layer in the non-gated region, thereby reducing the risk of degradation in the dynamic resistance of the device and the resistance degradation after HTOL, resulting in gallium nitride devices with superior performance.

[0090] Based on the gallium nitride device provided in the embodiments of the present application, an embodiment of the present application further provides a method for manufacturing a gallium nitride device. Figure 11 is a flowchart of a method for manufacturing a gallium nitride device according to an embodiment of the present application. Figures 12 to 21 are schematic diagrams of the structure of a gallium nitride device in a manufacturing process according to an embodiment of the present application. The manufacturing method may include the following steps:

[0091] S101: As shown in FIG. 12, obtain a gallium nitride layer 220.

[0092] In a possible embodiment, the thickness of the gallium nitride layer 220 may be greater. In this case, the gallium nitride layer 220 may be a substrate, the material of which is gallium nitride. The substrate provides a support function for the membrane layers on the substrate and is also used as an element of the AlGaN / GaN heterostructure.

[0093] In another possible embodiment, the gallium nitride layer 220 may be thin. As shown in FIG. 12 , the gallium nitride layer 220 may be formed on a substrate 200. The substrate 200 provides a support function for the film layers on the substrate 200. The gallium nitride layer 220 is used as an element of an AlGaN / GaN heterostructure, and the material of the substrate 200 may be one or more of aluminum nitride (AlN), silicon (Si), silicon carbide (SiC), and sapphire. Optionally, a buffer layer 210 may be further disposed between the substrate 200 and the gallium nitride layer 220, and the material of the buffer layer 210 may be aluminum nitride or low-temperature grown gallium nitride.

[0094] In a particular implementation, a buffer layer 210 may first be formed on the surface of the substrate 200, and then a gallium nitride layer 220 may be formed on the buffer layer 210. The gallium nitride layer 220 may be formed by a metalorganic chemical vapor deposition (MOCVD) method.

[0095] The gallium nitride layer 220 may have a gate region 1001 and a non-gated region 1002 outside the gate region 1001, and the gate region 1001 and the non-gated region 1002 are regions on the surface of the gallium nitride layer 220. The gate region 1001 is used to form the gate 251 and may be the central region between the regions where the source 252 and the drain 253 are located. The gate region 1001 may be equal to or larger than the region where the gate 251 is located. As shown in FIG. 12 , the dashed frame in the center represents the gate region 1001, and the dashed frame on either side of the gate region 1001 represents the non-gated regions 1002.

[0096] S102: As shown in Figures 13 to 21, barrier layers 231 & 232 are formed on the surface on the side of the gallium nitride layer 220, and a gate 251 is formed on the side of the barrier layers 231 & 232 located in the gate region 1001 away from the gallium nitride layer 220.

[0097] In this embodiment of the present application, the barrier layers 231 & 232 may be formed on the surface of the gallium nitride layer 220. The barrier layers 231 & 232 are located on the surface of the gallium nitride layer 220, and the constituent elements of the barrier layers 231 & 232 include aluminum, gallium, and nitrogen, and the constituent material of the barrier layers 231 & 232 is aluminum gallium nitride (Al x Ga 1-x The gallium nitride layer 220 and the barrier layers 231 & 232, whose material is aluminum gallium nitride, form an AlGaN / GaN heterostructure, generating two-dimensional electron gas. Based on this, a gallium nitride device can be formed that uses the two-dimensional electron gas generated by the heterostructure. When the gallium nitride layer 220 is disposed on the substrate 200, the barrier layers 231 & 232 are disposed on the side of the gallium nitride layer 220 that is away from the substrate 200.

[0098] In this embodiment of the present application, the barrier layers 231 & 232 are located in the gate region 1001 and the non-gated region 1002. In a direction perpendicular to the surface of the gallium nitride layer 220 (i.e., the vertical direction), the size of the barrier layer located in the gate region 1001 is larger than the size of the barrier layer located in the non-gated region 1002. In addition, the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gate 251.

[0099] The aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the aluminum concentration of the barrier layer in the gate region 1001 on the side facing the gate 251. Correspondingly, the gallium concentration of the barrier layer in the gate region 1001 on the side facing the gallium nitride layer 220 is higher than the gallium concentration of the barrier layer in the gate region 1001 on the side facing the gate 251. Because this setting is located in the gate region 1001, the aluminum content in the gate region 1001 is reduced from the side facing the gallium nitride layer 220 to the side facing the gate 251. The portion with a lower aluminum content has a lower barrier height. Therefore, a low barrier exists between the portion with a lower aluminum content and the gallium nitride layer 220. In this structure, the aluminum content is reduced from the side facing the gallium nitride layer 220 to the side facing the gate 251. Because the polarization effect generates holes in the barrier layers 231 & 232, the barrier layers 231 & 232 of the gate region 1001 can naturally correspond to p-type doping without Mg doping, the number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 of the gate region 1001, and the electrons in the two-dimensional electron gas channel 222 can be naturally depleted.

[0100] Additionally, in the p-GaN solution, the hole concentration is strongly related to Mg activation, and therefore parameters such as the p-GaN activation temperature and doping concentration must be precisely controlled. Compared to the p-GaN solution, in this embodiment of the present application, holes are generated by the polarization effect, and the number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 of the gate region 1001. This eliminates the need for precise control of hole activation in the Mg doping technique. Additionally, the absence of a p-GaN layer eliminates the problem of defect states caused by Mg diffusion. Furthermore, the threshold voltage of the device is determined by the structure of the gate region 1001, resulting in a large process window. Therefore, the threshold voltage is not easily affected by the Mg doping concentration and p-GaN activation conditions.

[0101] Specifically, the barrier layers 231 & 232 may include a first portion 231 facing the gallium nitride layer 220 and a second portion 232 facing the gate 251. The first portion 231 is formed in the gate region 1001 and the non-gated region 1002, and the protrusion of the second portion 232 above the surface of the gallium nitride layer 220 is located in the gate region. In other words, the second portion 232 can be considered to be formed in the first portion 231 of the gate region 1001, and the second portion 232 in the gate region 1001. The aluminum concentration in the first portion 231 is higher than the aluminum concentration in the second portion 232, and correspondingly, the gallium concentration in the first portion 231 is higher than the gallium concentration in the second portion 232. Because the second portion 232 is formed in the gate region 1001, the aluminum content in the gate region 1001 is reduced from the first portion 231 to the second portion 232. The portion with a lower aluminum content has a lower barrier height, thus creating a lower barrier between the portion with a lower aluminum content and the gallium nitride layer 220. In this structure, the aluminum content decreases from the first portion 231 to the second portion 232. Because the polarization effect generates holes in the first portion 231 and the second portion 232, the barrier layers 231 and 232 in the gate region 1001 can naturally correspond to p-type doping without Mg doping. The number of holes is essentially equal to the number of electrons in the two-dimensional electron gas channel 222 in the gate region 1001, and the electrons in the two-dimensional electron gas channel 222 can naturally be depleted.

[0102] In this embodiment of the present application, the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is 3 / 7 or greater. In other words, the molar ratio of aluminum to gallium in the first portion 231 is 3 / 7 or greater, i.e., x1≧30%. Therefore, the first portion 231 has a high barrier height and can effectively generate two-dimensional electron gas. The size (i.e., vertical size) of the first portion 231 (i.e., the barrier layer in the non-gated region 1002) in a direction perpendicular to the surface of the gallium nitride layer 220 may be 30 nm or less, for example, 5 nm. When the aluminum gallium nitride layer is within this size range, the two-dimensional electron gas channel in the gated region 1001 is easily depleted.

[0103] In an embodiment for forming the barrier layers 231 & 232 and the gate, as shown in FIG. 13, an aluminum gallium nitride material layer 230 may first be formed on the surface on the side of the gallium nitride layer 220, and then the aluminum gallium nitride material layer 230 located in the non-gated region 1002 may be etched to reduce its thickness and obtain the barrier layer. As shown in FIG. 14, the barrier layer may include a first portion 231 and a second portion 232, where the first portion 231 is located in the gated region 1001 and the non-gated region 1002, and the second portion 232 is located in the gated region 1001. Next, as shown in FIGS. 15-17, 4, and 9, a gate 251 is formed on the side of the barrier layer located in the gated region 1001 away from the gallium nitride layer 220. The constituent elements of the aluminum gallium nitride material layer 230 include aluminum, gallium, and nitrogen. The aluminum concentration on the side of aluminum gallium nitride material layer 230 facing gallium nitride layer 220 is higher than the aluminum concentration on the side of aluminum gallium nitride material layer 230 away from gallium nitride layer 220 .

[0104] Specifically, the aluminum concentration of the aluminum gallium nitride material layer 230 is higher on the side facing the gallium nitride layer 220, and lower on the side away from the gallium nitride layer 220. The entire aluminum gallium nitride material layer 230 may be a monolithic structure without clear boundaries, or may include multiple sub-layers. Specifically, when the aluminum gallium nitride material layer 230 has a monolithic structure, the aluminum gallium nitride material layer 230 can be obtained using the same deposition process. In the deposition process, the aluminum concentrations at different thicknesses can be adjusted by separately adjusting the deposition rates of aluminum and gallium. Therefore, etching the aluminum gallium nitride material layer 230 in the non-gated region 1002 corresponds to thinning a portion of the aluminum gallium nitride material layer 230. After thinning, the portion that still covers the gated region 1001 and the non-gated region 1002 is used as the first portion 231, and the portion located in the gated region 1001 is used as the second portion 232. For ease of explanation, a subinterface is defined between first portion 231 and second portion 232. The subinterface is the plane on which the top surface of first portion 231 lies and is represented as a horizontal dashed line in Figure 14. The same representation is used in subsequent schematic diagrams of the structure.

[0105] The formed barrier layers 231 & 232 have a greater thickness in the gate region 1001 and a smaller thickness in the non-gated region 1002. As shown in FIG. 14 , the thickness of the barrier layers 231 & 232 in the non-gated region 1002 is equal to the thickness of the first portion 231, and the thickness of the barrier layers 231 & 232 in the gate region 1001 is equal to the sum of the thickness of the first portion 231 and the thickness of the second portion 232. The aluminum gallium nitride material layer 230 may be formed by an MOCVD method. The aluminum gallium nitride material layer 230 may be etched using a photoetching process. The etching method may be anisotropic dry etching. The etching thickness may be controlled using an etching rate and an etching duration.

[0106] In some possible implementations, after the barrier layers 231 and 232 are formed, a passivation layer 240 may be further formed on the surface of the barrier layer in the non-gated region 1002 to generate stress, thereby regenerating the two-dimensional electron gas channel 222 in the first portion 231, which helps to implement a channel with a high charge transfer rate. The material of the passivation layer 240 may be at least one of silicon nitride and aluminum carbide. In this case, forming a gate 251 on the side of the barrier layer located in the gate region 1001 and away from the gallium nitride layer 220 may specifically involve forming a passivation layer 240 covering the barrier layer, etching the passivation layer 240 covering the barrier layer in the gate region 1001 to form a gate hole 270 penetrating the passivation layer 240 as shown in FIG. 15, and forming a gate 251 in the gate hole 270 as shown in FIG. 16. As shown in FIG. 4, the formed passivation layer 240 covers the first portion 231 and the second portion 232, and may, for example, cover the sidewalls of the second portion 232 or cover a portion of the top surface of the second portion 232.

[0107] The gate 251 may include an electrically connected first gate structure and a second gate structure. The first gate structure is located in the gate hole and penetrates the passivation layer 240. The second gate structure is formed on the side of the first gate structure away from the substrate 200 and covers a portion of the surface of the passivation layer 240. In other words, the gate 251 may form a "T"-shaped structure to improve the pull-out reliability of the gate 251. The first gate structure and the second gate structure may be formed by deposition and etching. Specifically, a conductive material may be deposited so that it fills the gate hole 270 and covers the upper part of the gate hole 270. The conductive material may be at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper. Next, the conductive material outside the gate region 1001 may be removed to form a gate located in the gate region 1001. Of course, the gate 251 may alternatively include only a first gate structure that penetrates the passivation layer 240 .

[0108] The gate 251 may be in direct contact with the second portion 232 to form a Schottky gate element structure. As shown in FIG. 4, the solution in which the gate 251 contacts the second portion 232 reduces the forward leakage current of the device compared to the solution in which the gate 251 contacts the first portion 231. A gate dielectric layer 260 may also be formed between the gate 251 and the second portion 232 of the barrier layer to form an insulated gate element structure. As shown in FIG. 9, the gate dielectric layer 260 contacts the second portion 232. The gate dielectric layer 260 may be in contact with the first portion 231 having a higher aluminum concentration. touch Compared to the solution where the gate 251 contacts the gate dielectric layer 260 and the gate dielectric layer 260 contacts the second portion 232, the solution where the gate 251 contacts the gate dielectric layer 260 and the gate dielectric layer 260 contacts the second portion 232 reduces interface defects and improves the threshold stability of the device.

[0109] In a manufacturing process of the insulated gate element, before the gate 251 is formed, a gate dielectric layer 260 may be formed between the second portion 232 and the gate 251. Specifically, a gate intermediate material layer 262 may be formed on the aluminum gallium nitride material layer 230. When the aluminum gallium nitride material layer 230 located in the non-gated region 1002 is etched, the gate intermediate material layer 262 located on the aluminum gallium nitride material layer 230 in the non-gated region 1002 is also etched to form the gate dielectric layer 260 located in the gate region 1001. The gate dielectric layer 260 is located between the gate 251 and the barrier layer, and the passivation layer 240 is formed on the gate dielectric layer 260. The gate dielectric layer 260 is exposed in a gate hole 270 obtained by etching the passivation layer 240. Specifically, after the gate hole 270 is formed, the gate dielectric layer 260 may be formed by deposition. A gate dielectric layer 260 covers the passivation layer 240 and covers the sidewalls and bottom of the gate hole 270. As shown in Figure 17, a gate 251 is formed in the gate hole 270, as shown in Figure 9.

[0110] 18, an aluminum gallium nitride material layer 230 may be formed on the surface of the gallium nitride layer 220, and a gate material layer 253 may be formed on the side of the aluminum gallium nitride material layer 230 away from the gallium nitride layer 220. To reduce the thickness, the gate material layer 253 on the side of the aluminum gallium nitride material layer 230 away from the gallium nitride layer in the non-gated region 1002 is etched, and the aluminum gallium nitride material layer 230 in the non-gated region is etched. In other words, the gate material layer 253 and the aluminum gallium nitride material layer 230 are etched in the non-gated region 1002 to obtain the barrier layers 231&232 and the gate 251 on the side of the barrier layer in the gate region 1001 away from the gallium nitride layer 220. 19 to 21, 8, and 10, the barrier layer includes a second portion 232 located in the gate region 1001 and a first portion 231 located in the gate region 1001 and the non-gated region 1002. The constituent material of the aluminum gallium nitride material layer 230 includes aluminum, gallium, and nitrogen. The aluminum concentration on the side of the aluminum gallium nitride material layer 230 facing the gallium nitride layer 220 is higher than the aluminum concentration on the side of the aluminum gallium nitride material layer 230 away from the gallium nitride layer 220. The material of the gate material layer 253 may be at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

[0111] Specifically, the aluminum concentration is high in the portion of the aluminum gallium nitride material layer 230 facing the gallium nitride layer 220, and low in the portion of the aluminum gallium nitride material layer 230 away from the gallium nitride layer 220. The entire aluminum gallium nitride material layer 230 may be a monolithic structure or may include multiple film layers. Specifically, when the aluminum gallium nitride material layer 230 has a monolithic structure, the aluminum gallium nitride material layer 230 can be obtained using the same deposition process. In the deposition process, the aluminum concentrations at different thicknesses can be adjusted by separately adjusting the deposition rates of aluminum and gallium. Therefore, etching the aluminum gallium nitride material layer 230 in the non-gated region 1002 corresponds to thinning a portion of the aluminum gallium nitride material layer 230. After thinning, the portion that still covers the gated region 1001 and the non-gated region 1002 is used as the first portion 231, and the portion located in the gated region 1001 is used as the second portion 232. For ease of explanation, a subinterface is defined between the first portion 231 and the second portion 232. The subinterface is a plane on which the top surface of the first portion 231 is located, and is represented as a horizontal dashed line in FIG. 19. The formed barrier layers 231 & 232 have a greater thickness in the gate region 1001 and a lesser thickness in the non-gated region 1002. As shown in FIG. 19, the thickness of the barrier layers 231 & 232 in the non-gated region 1002 is equal to the thickness of the first portion 231, and the thickness of the barrier layers 231 & 232 in the gate region 1001 is equal to the sum of the thickness of the first portion 231 and the thickness of the second portion 232.

[0112] The gate 251 may be in direct contact with the second portion 232 to form a Schottky gate element structure. As shown in FIG. 8 , compared to a solution in which the gate 251 contacts the first portion 231, the solution in which the gate 251 contacts the second portion 232 reduces the forward leakage current of the device. A gate dielectric layer 260 may also be formed between the gate 251 and the second portion 232 to form an insulated gate element structure. As shown in FIG. 10 , compared to a solution in which the gate dielectric layer 260 contacts the first portion 231 having a higher aluminum concentration and the gate dielectric layer 260 directly contacts the first portion 231 having a higher aluminum concentration, the solution in which the gate 251 contacts the gate dielectric layer 260 and the gate dielectric layer 260 contacts the second portion 232 reduces interface defects and improves the threshold stability of the device.

[0113] In the manufacturing process of the insulated gate element, a gate intermediate material layer 262 may be further formed between the aluminum gallium nitride material layer 230 and the gate material layer 253. As shown in FIG. 20 , when the gate material layer 253 on the side of the aluminum gallium nitride material layer located in the non-gated region 1002 away from the gallium nitride layer is etched and the aluminum gallium nitride material layer 230 located in the non-gated region is thinned, the gate intermediate material layer 262 on the side of the aluminum gallium nitride material layer located in the non-gated region 1002 away from the gallium nitride layer may be simultaneously etched to obtain a gate dielectric layer 260 located in the gate region 1001. The gate dielectric layer 260 is located between the barrier layers 231&232 and the gate 251, as shown in FIG. 21 .

[0114] In some possible implementations, after the barrier layers 231 and 232 are formed, a passivation layer 240 may be further formed on the surface of the barrier layer in the non-gated region 1002 (i.e., on the surface of the first portion 231) to generate stress, which regenerates the two-dimensional electron gas channel 222 in the first portion 231, which helps to implement a channel with a high charge transfer rate. The material of the passivation layer 240 may be at least one of silicon nitride and aluminum carbide. In this case, after the gate 251 is formed, the passivation layer 240 may be formed to cover the barrier layers 231 and 232. As shown in FIGS. 8 and 10 , the passivation layer 240 covers the sidewalls of the second portion 232 and the top surface of the first portion 231.

[0115] In this embodiment of the present application, the aluminum concentration of the first portion 231 being higher than the aluminum concentration of the second portion 232 may be considered as the average aluminum concentration of the first portion 231 being higher than the average aluminum concentration of the second portion 232, and the aluminum concentration of the second portion 232 may be uniform or non-uniform. Specifically, the second portion 232 may include multiple stacked sub-film layers, where the multiple sub-film layers are stacked vertically. The aluminum concentrations of the multiple sub-film layers may not be exactly the same. The aluminum concentration of the sub-film layer facing the gate 251 is lower than the aluminum concentration of the sub-film layer facing the first portion 231. In other words, the aluminum concentration of the upper sub-film layer may be lower than the aluminum concentration of the lower sub-film layer. In this manner, the aluminum concentration gradually decreases from the side facing the first portion 231 to the side away from the first portion 231. The aluminum concentration of each sub-layer exhibits a decreasing trend, resulting in a stepwise decrease in aluminum concentration, enhancing the polarization effect in the barrier layers 231 and 232 of the gate region 1001. Specifically, the second portion 232 may instead be a monolithic structure without a clear boundary, i.e., the aluminum content of the second portion 232 may not have a clear, abrupt change, and the aluminum concentration of the second portion 232 exhibits a decreasing trend from the side facing the first portion 231 to the side away from the first portion 231. The decreasing trend may be continuous and uniform, or may be uneven. 6B in As shown in Fig. 1, the aluminum concentration at different film layer heights within the first portion 231 is the same, and the aluminum concentration in the second portion 232 decreases at a uniform rate from the side facing the first portion 231 to the side away from the first portion 231.

[0116] In this embodiment of the present application, a source 252 and a drain 253 may be further formed on the barrier layer in the non-gated region 1002. Specifically, the source 252 and the drain 253 are formed on the first portion 231 and are located on both sides of the gate 251, respectively. The source 252 and the drain 253 may be formed on the surface of the first portion 231, or may be formed in a through-hole obtained by etching the first portion 231. The material of the source 252 and / or the drain 253 is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

[0117] One embodiment of the present application provides a method for manufacturing a gallium nitride device to obtain a gallium nitride layer. The gallium nitride layer has a gate region and a non-gated region outside the gate region. A barrier layer is formed on the surface of the gallium nitride layer, and a gate is located on the side of the barrier layer in the gate region away from the gallium nitride layer. The constituent elements of the barrier layer include aluminum, gallium, and nitrogen. The barrier layer is located in the gate region and the non-gated region. In a direction perpendicular to the surface of the gallium nitride layer, the size of the barrier layer in the gate region is larger than the size of the barrier layer in the non-gated region, and the aluminum concentration of the side of the barrier layer in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer in the gate region facing the gate. In this way, the aluminum concentration in the barrier layer decreases in the direction toward the gate region away from the gallium nitride layer. Based on the polarization effect, the barrier layer can naturally correspond to p-type doping without Mg doping, thereby naturally depleting electrons at the AlGaN / GaN interface in the gate region and not depleting the two-dimensional electron gas channel in the non-gated region. In addition, when forming normally closed gallium nitride devices, the Mg doping prevents the formation of defect states in the barrier layer in the non-gated region, thereby reducing the risk of degradation in the dynamic resistance of the device and the resistance degradation after HTOL, resulting in gallium nitride devices with superior performance.

[0118] Based on the gallium nitride element provided in the embodiment of the present application, an embodiment of the present application further provides an electronic device. The electronic device includes a circuit board and a gallium nitride element connected to the circuit board. The gallium nitride element can be any of the gallium nitride elements provided above. The circuit board can be a printed circuit board (PCB). Of course, the circuit board can alternatively be a flexible circuit board (FPC) or the like. In this embodiment, the circuit board is not limited. Optionally, the electronic device can be various types of electronic devices, such as a computer, a mobile phone, a tablet computer, a wearable device, and an in-vehicle device. Machine The electronic device may alternatively be a network device such as a base station.

[0119] Optionally, the electronic device further includes a package substrate, the package substrate being fixed onto a printed circuit board PCB using solder balls, and the gallium nitride element being fixed onto the package substrate using solder balls.

[0120] In another aspect of the present application, there is further provided a non-transitory computer-readable storage medium for use with a computer, the computer having software for creating a gallium nitride device, the computer-readable storage medium storing one or more computer-readable data structures, the one or more computer-readable data structures having optical mask data for fabricating the gallium nitride device provided in any one of the preceding figures.

[0121] All embodiments herein are described step by step, and for the same or similar parts of the embodiments, reference may be made to these embodiments, with each embodiment focusing on the differences from other embodiments.

[0122] The foregoing provides specific embodiments of the present application. It should be understood that the foregoing embodiments are only intended to illustrate the technical solutions of the present application, and are not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that, without departing from the scope of the technical solutions of the embodiments of the present application, they may further modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some technical features thereof. [Explanation of symbols]

[0123] 110 Gallium nitride layer 120 Aluminum gallium nitride layer 130 p-GaN material layer 131 p-GaN layer Gate 141 142 Source 143 Drain 200 boards 210 Buffer Layer 220 Gallium nitride layer 221 Two-dimensional electron gas channel 222 Two-dimensional electron gas channel 230 Aluminum gallium nitride material layer 231 First portion of the barrier layer 232 Second portion of the barrier layer 240 Passivation Layer Gate 251 252 Source 253 Drain 253 Gate material layer 260 gate dielectric layer 262 Gate intermediate material layer 270 Gate Hall 1001 gate area 1002 Non-gated region

Claims

1. A gallium nitride device, comprising: a gallium nitride layer having a gate region and a non-gated region outside the gate region; a barrier layer located on a surface of the gallium nitride layer, the barrier layer being made of aluminum, gallium, and nitrogen; a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer; Equipped with a gallium nitride device, wherein the barrier layer is located in the gate region and the non-gated region, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region in a direction perpendicular to the surface of the gallium nitride layer, the aluminum concentration of the barrier layer located in the gate region on a side facing the gallium nitride layer is higher than the aluminum concentration of the barrier layer located in the gate region on a side facing the gate, and the gallium concentration of the barrier layer located in the gate region on a side facing the gallium nitride layer is higher than the gallium concentration of the barrier layer located in the gate region on a side facing the gate.

2. 2. The gallium nitride device of claim 1, wherein the barrier layer comprises a first portion facing the gallium nitride layer and a second portion facing the gate, the first portion having a higher aluminum concentration than the second portion, the first portion being located in the gate region and the non-gated region, and the second portion on the surface of the gallium nitride layer being located in the gate region.

3. 3. The gallium nitride device of claim 2, wherein the first portion is a first film layer and the second portion comprises a plurality of stacked sub-film layers, and the aluminum concentration of the sub-film layer facing the gate is lower than the aluminum concentration of the sub-film layer facing the first portion.

4. 3. The gallium nitride device according to claim 2, wherein the aluminum concentration in the second portion exhibits a decreasing trend from the side facing the first portion to the side away from the first portion.

5. 5. The gallium nitride device according to claim 1, wherein the size of the barrier layer located in the non-gated region in the direction perpendicular to the surface of the gallium nitride layer is 30 nm or less.

6. 6. The gallium nitride device according to claim 2, wherein the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is 3 / 7 or more.

7. a source and a drain, the source and the drain being located on a side of the barrier layer in the non-gated region away from the gallium nitride layer; 7. The gallium nitride device according to claim 1, comprising:

8. 8. The gallium nitride device of claim 7, wherein a material of at least one of the source, the drain, and the gate is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

9. a passivation layer covering the barrier layer located in the non-gated region; 9. The gallium nitride device according to claim 1, comprising:

10. 10. The gallium nitride device of claim 9, wherein the passivation layer covers the barrier layer located in the gate region, the gate comprising an electrically connected first gate structure and a second gate structure, the first gate structure penetrating the passivation layer, and the second gate structure formed on a side of the first gate structure away from the gallium nitride layer and covering a portion of a surface of the passivation layer.

11. 11. The gallium nitride device according to claim 9, wherein the material of the passivation layer is at least one of silicon nitride and aluminum carbide.

12. a gate dielectric layer located between the barrier layer and the gate; 12. The gallium nitride device according to claim 1, comprising:

13. a substrate located on a side of the gallium nitride layer away from the barrier layer; 13. The gallium nitride device according to claim 1, comprising:

14. a buffer layer positioned between the substrate and the gallium nitride layer; 14. The gallium nitride device of claim 13, comprising:

15. 1. A method for manufacturing a gallium nitride device, comprising: obtaining a gallium nitride layer, the gallium nitride layer having a gate region and a non-gated region outside the gate region; forming a barrier layer on a surface on the gallium nitride layer side and a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer, wherein elements of a constituent material of the barrier layer include aluminum, gallium, and nitrogen, the barrier layer is located in the gate region and the non-gated region, the size of the barrier layer located in the gate region is larger than the size of the barrier layer located in the non-gated region in a direction perpendicular to the surface of the gallium nitride layer, the aluminum concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the aluminum concentration of the side of the barrier layer located in the gate region facing the gate, and the gallium concentration of the side of the barrier layer located in the gate region facing the gallium nitride layer is higher than the gallium concentration of the side of the barrier layer located in the gate region facing the gate; A method comprising:

16. 16. The method of claim 15, wherein the barrier layer comprises a first portion facing the gallium nitride layer and a second portion facing the gate, the first portion having a higher aluminum concentration than the second portion, the first portion being located in the gate region and the non-gated region, and the second portion on the surface of the gallium nitride layer being located in the gate region.

17. 17. The method of claim 16, wherein the first portion is a first film layer and the second portion comprises a plurality of stacked sub-film layers, and the aluminum concentration of the sub-film layer facing the gate is lower than the aluminum concentration of the sub-film layer facing the first portion.

18. 17. The method of claim 16, wherein the aluminum concentration of the second portion exhibits a decreasing trend from a side facing the first portion to a side away from the first portion.

19. 19. The method according to claim 15, wherein the size of the barrier layer located in the non-gated region in the direction perpendicular to the surface of the gallium nitride layer is 30 nm or less.

20. 20. The method of claim 15, wherein the molar ratio of aluminum to gallium in the barrier layer located in the non-gated region is 3 / 7 or greater.

21. forming a source and a drain on a side of the barrier layer in the non-gated region away from the gallium nitride layer; 21. The method of any one of claims 15 to 20, comprising:

22. 22. The method of claim 21, wherein a material of at least one of the source, the drain, and the gate is at least one of nickel, titanium, aluminum, palladium, platinum, gold, titanium nitride, tantalum nitride, and copper.

23. The step of forming a barrier layer on a surface of the gallium nitride layer side and a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer comprises: forming an aluminum gallium nitride material layer on the surface of the side of the gallium nitride layer, wherein the constituent elements of the aluminum gallium nitride material layer include aluminum, gallium, and nitrogen, and the aluminum concentration of the side of the aluminum gallium nitride material layer facing the gallium nitride layer is higher than the aluminum concentration of the side of the aluminum gallium nitride material layer away from the gallium nitride layer; thinning the layer of aluminum gallium nitride material located in the non-gated area to obtain the barrier layer; forming the gate on the side of the barrier layer located in the gate region away from the gallium nitride layer; 23. The method of any one of claims 15 to 22, comprising:

24. forming the gate on the side of the barrier layer located in the gate region away from the gallium nitride layer, forming a passivation layer overlying the barrier layer; etching the passivation layer covering the barrier layer in the gate region to form a gate hole through the passivation layer, and forming the gate in the gate hole; 24. The method of claim 23, comprising:

25. 25. The method of claim 24, wherein the gate comprises an electrically connected first gate structure and a second gate structure, the first gate structure being located in the gate hole, and the second gate structure being formed on a side of the first gate structure away from the gallium nitride layer and covering a portion of a surface of the passivation layer.

26. Prior to the step of forming the gate, the method further comprises: forming a gate dielectric layer between the barrier layer and the gate; 26. The method of any one of claims 23 to 25, comprising:

27. The step of forming a barrier layer on a surface of the gallium nitride layer side and a gate located on a side of the barrier layer in the gate region away from the gallium nitride layer comprises: forming an aluminum gallium nitride material layer on the surface of the side of the gallium nitride layer and a gate material layer located on a side of the aluminum gallium nitride material layer remote from the gallium nitride layer, wherein the constituent elements of the aluminum gallium nitride material layer include aluminum, gallium, and nitrogen, and the aluminum concentration of the side of the aluminum gallium nitride material layer facing the gallium nitride layer is higher than the aluminum concentration of the side of the aluminum gallium nitride material layer remote from the gallium nitride layer; etching the gate material layer located on a side of the aluminum gallium nitride material layer remote from the gallium nitride layer in the non-gated region to obtain the barrier layer and the gate located on the side of the barrier layer remote from the gallium nitride layer in the gate region, and thinning the aluminum gallium nitride material layer located in the non-gated region; 23. The method of any one of claims 15 to 22, comprising:

28. The method of claim 27, further comprising forming a gate intermediate material layer on the aluminum gallium nitride material layer before the gate material layer is formed; etching the gate intermediate material layer located on a side of the aluminum gallium nitride material layer in the non-gated region away from the gallium nitride layer to obtain a gate dielectric layer located between the barrier layer and the gate when the gate material layer located on a side of the aluminum gallium nitride material layer in the non-gated region away from the gallium nitride layer is etched and the aluminum gallium nitride material layer located in the non-gated region is thinned; 28. The method of claim 27, comprising:

29. After the step of forming the barrier layer, the method further comprises: forming a passivation layer overlying the barrier layer; 29. The method of claim 27 or 28, comprising:

30. 30. The method of claim 24, 25, or 29, wherein the material of the passivation layer is at least one of silicon nitride and aluminum carbide.

31. The method of claim 15, wherein the gallium nitride layer is formed on a substrate.

32. 32. The method of claim 31 , wherein a buffer layer is formed on the substrate and the gallium nitride layer is formed on the buffer layer.

33. 15. An electronic device comprising: a circuit board; and the gallium nitride element according to claim 1 connected to the circuit board.

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