GaN diode and manufacturing method thereof
By adopting InAlN/GaN heterostructure and depletion block structure in GaN Schottky diodes, the problems of low reverse voltage withstand voltage and interface damage in the prior art are solved, and the effects of low forward turn-on voltage and high reverse voltage withstand voltage are achieved.
Patent Information
- Application Number
- CN202411767294.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-04
- Publication Date
- 2025-03-18
AI Technical Summary
During the groove etching process of existing GaN Schottky diodes, the interface barrier between the anode metal and the GaN channel layer is low, resulting in a lower reverse withstand voltage, and groove etching will damage the interface and increase leakage current.
InAlN/GaN heterostructure is adopted, and depletion blocks are provided on both sides of the groove. The anode metal covers the depletion block and forms ohmic contact with the GaN channel layer. The depletion and closure of the two-dimensional electron gas are controlled through the depletion block.
On the basis of the lower forward opening voltage, the reverse voltage withstand of the GaN diode is significantly improved, and the impact of interface damage on device performance during groove etching is weakened.
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Figure CN119653789A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a GaN diode and a manufacturing method thereof. Background Art
[0002] High-power gallium nitride Schottky diodes (GaN SBDs), as core devices for rectifier circuits and limiting circuits, have received extensive attention in recent years. In GaN SBD research, the mainstream uses AlGaN / GaN heterojunction epitaxial materials. High-power SBD applications require high current capabilities, so they require high density of the two-dimensional electron gas (2DEG). In contrast, InAlGaN / GaN heterostructures are more suitable for making high-power GaN SBDs.
[0003] At present, SBDs made of InAlN and GaN are mainly groove-type structures to reduce the forward turn-on voltage of the SBD and reduce the on-resistance of the device.
[0004] However, the potential barrier of the interface between the anode metal and the GaN channel layer formed after etching the groove is relatively low. At the same time, during the groove etching process, the interface between the anode metal and the GaN channel layer will be damaged, resulting in a large number of interface states. The electrons at the anode can easily enter the channel layer through the interface states, forming a leakage current. The above two points make the reverse withstand voltage of the device low. Summary of the invention
[0005] The object of the present invention is to provide a GaN diode and a method for manufacturing the same, so as to ensure that the reverse withstand voltage of the device is improved on the basis of a relatively small forward turn-on voltage.
[0006] To achieve the above object, the present invention provides the following solutions:
[0007] In a first aspect, the present invention provides a GaN diode, comprising:
[0008] A stacked substrate, a GaN buffer layer, a GaN channel layer and an InAlN barrier layer;
[0009] Wherein, a two-dimensional electron gas is formed on one side of the GaN buffer layer close to the InAlN barrier layer;
[0010] An anode region and cathode regions located on both sides of the anode region are arranged on the top of the InAlN barrier layer, and a portion of metal of the anode region is arranged in a groove penetrating the InAlN barrier layer and forms an ohmic contact with the GaN channel layer;
[0011] Depletion blocks are deposited on the top of the InAlN barrier layer on both sides of the groove, the depletion blocks are in contact with the metal of the anode region on the top of the InAlN barrier layer, and the depletion blocks are used to deplete the two-dimensional electron gas in the projection area on the channel layer.
[0012] Optionally, in the GaN diode provided by the present application, the anode metal covers the depletion block.
[0013] Optionally, in the GaN diode provided by the present application, at least two pairs of depletion blocks are arranged on the top of the InAlN barrier layer.
[0014] Optionally, in the GaN diode provided in the present application, the depletion block has a thickness of 30-70 nm and a width of 1-10 um.
[0015] Optionally, in the GaN diode provided by the present application, the depletion block is P-type InGaN.
[0016] Optionally, in the GaN diode provided in the present application, the P-type InGaN is doped with Mg, and the concentration of Mg is 4E17 / cm -3 -2E19 / cm -3 .
[0017] Optionally, in the GaN diode provided by the present application, the composition of In in the P-type InGaN is 0.05-0.1%.
[0018] Optionally, in the GaN diode provided in the present application, the composition of InAlN in the InAlN barrier layer is In0.17Al0.83N.
[0019] Optionally, in the GaN diode provided in the present application, the GaN buffer layer has a thickness of 3um-5um; the GaN channel layer has a thickness of 300-700nm; the InAlN barrier layer has a thickness of 10-20nm; and the depth of the groove on the GaN channel layer is 1-10nm.
[0020] In a second aspect, the present application provides a method for manufacturing a GaN diode, the method comprising:
[0021] Epitaxially growing a GaN buffer layer, a GaN channel layer and an InAlN barrier layer in sequence on a substrate, so that a two-dimensional electron gas is formed on a side of the GaN buffer layer close to the InAlN barrier layer;
[0022] Growing a SiO2 layer on top of the InAlN barrier layer and removing the SiO2 layer in a target area, wherein the target area is used for depositing a depletion block, and at least two target areas are arranged on top of the InAlN barrier layer;
[0023] Depositing a depletion block on the target area to deplete the two-dimensional electron gas in a projection area on the channel layer;
[0024] Etching a groove in the anode region on the top of the InAlN barrier layer, so that the groove penetrates the InAlN barrier layer and extends to the GaN channel layer, and the groove is located between the two target regions;
[0025] Depositing an anode metal in the groove so that the anode metal covers the depletion block and forms an ohmic contact with GaN of the GaN channel layer;
[0026] The cathode regions on both sides of the anode region on the top of the InAlN barrier layer are etched to form recesses, and cathode metal is deposited in the recesses.
[0027] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:
[0028] It can be understood that the GaN diode and its manufacturing method provided in the present application form an InAlN / GaN heterostructure by adopting an InAlN barrier layer and a GaN channel layer, and deposit an anode metal by adopting a groove structure, and form an ohmic contact with the GaN of the GaN channel layer in the groove, and then set a depletion block in contact with the anode metal on the InAlN barrier layer on both sides of the groove, so that the anode voltage can directly control the depletion and closure of the two-dimensional electron gas of the GaN channel layer, so that when a reverse voltage is applied to the GaN diode device, the depletion block can be controlled to deplete the two-dimensional electron gas, so that the two-dimensional electron gas is in a disconnected state and cannot form a current path, thereby improving the reverse withstand voltage of the GaN diode device; when a forward voltage is applied to the GaN diode device, the depletion effect of the depletion block on the 2DEG below is weakened, the two-dimensional electron gas begins to close, the electrons move from the cathode to the anode to form a current, and the diode is turned on in the forward direction. That is, due to the arrangement of the above-mentioned diode structure, the turn-on voltage of the diode depends on the degree of depletion of the 2DEG by the depletion block, that is, it depends on the hole concentration in the depletion block, and the reverse withstand voltage also depends on the degree of depletion of the 2DEG by the depletion block, and has nothing to do with the interface barrier between the anode metal and GaN, so that even if there are a large number of interface states in the etching process of the groove, the forward turn-on voltage and reverse withstand voltage of the device are not affected. Therefore, the GaN diode device provided by the present application effectively improves the reverse withstand voltage on the basis of ensuring a lower forward turn-on voltage, making the process window larger, and has potential application prospects. BRIEF DESCRIPTION OF THE DRAWINGS
[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0030] Figure 1 A schematic diagram of the structure of a GaN diode in the related art;
[0031] Figure 2 A schematic diagram of the structure of a GaN diode in some embodiments of the present application;
[0032] Figure 3 Schematic diagram of the structure of GaN diodes in some other embodiments of the present application;
[0033] Figure 4 Schematic diagram of the process of manufacturing a GaN diode according to some embodiments of the present application. DETAILED DESCRIPTION
[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.
[0036] It is understandable that for high-power gallium nitride Schottky diodes (GaN SBDs), AlGaN / GaN heterojunction epitaxial materials are usually used. High-power SBD applications require higher current capabilities, and therefore higher density of the two-dimensional electron gas (2DEG). AlGaN / GaN materials are usually made of Al 0.2 Ga 0.8 If the 2DEG density is to be increased, the Al component needs to be further increased. However, after the Al component is increased, the lattice mismatch between AlGaN and GaN is aggravated, which has a serious impact on the crystal quality and device reliability. In contrast, the InAlGaN / GaN heterostructure is more suitable for making high-power GaN SBD, especially In 0.17 Al 0.83 N material has a strong spontaneous polarization effect. 0.17 Al 0.83 The 2DEG density of N / GaN is Al0.2 Ga 0.8 N / GaN is more than twice, and In 0.17 Al 0.83 The lattice constant of N matches that of GaN, so the material quality and device reliability will be better.
[0037] like Figure 1 As shown in FIG. 1 , in the related art, the SBD made of InAlN and GaN is mainly a groove-type structure. The groove-type structure can reduce the forward turn-on voltage of the SBD and reduce the on-resistance of the device.
[0038] However, since the interface between the anode metal and the GaN channel layer formed after etching the groove has a relatively low potential barrier, the reverse withstand voltage is relatively small. At the same time, during the groove etching process, the interface between the anode metal and the GaN channel layer will be damaged, resulting in a large number of interface states. The electrons of the anode can easily enter the channel layer through the interface states, forming leakage current, which also reduces the reverse withstand voltage of the device.
[0039] In the embodiment of the present application, in order to improve the reverse withstand voltage of the device while ensuring a lower forward conduction voltage, a novel groove-type GaN diode is proposed, which adopts an InAlN / GaN heterostructure (In 0.17 Al 0.83 N / GaN), and grow depletion blocks (such as P-type InGaN layer) of a certain area on both sides of the groove as electron depletion regions to deplete the 2DEG below; at the same time, the anode metal is in contact with the depletion block, so that the anode voltage can directly control the two-dimensional electron gas of the channel layer, ultimately achieving an improvement in the reverse withstand voltage of the device.
[0040] Furthermore, due to the setting of the depletion block, even if a large number of interface states exist in the groove during the etching process, the forward turn-on voltage and reverse withstand voltage of the device are not affected, the process window is larger, and there is potential application prospect.
[0041] In order to better understand the GaN diode and its manufacturing method provided by the present application, it is described in detail below with reference to the accompanying drawings.
[0042] Figure 2 Shown is a schematic structural diagram of a GaN diode according to some embodiments of the present application.
[0043] like Figure 2 As shown, the structure specifically includes:
[0044] A stacked substrate, a GaN buffer layer, a GaN channel layer and an InAlN barrier layer;
[0045] Wherein, a two-dimensional electron gas is formed on a side of the GaN buffer layer close to the InAlN barrier layer;
[0046] An anode region and cathode regions located on both sides of the anode region are arranged on the top of the InAlN barrier layer, a portion of the metal of the anode region is arranged in a groove penetrating the InAlN barrier layer and forms an ohmic contact with GaN in the GaN channel layer, and a portion of the metal covers the InAlN barrier layer;
[0047] Depletion blocks are deposited on the top of the InAlN barrier layer on both sides of the groove. The depletion blocks are in contact with the anode metal on the InAlN barrier layer. The depletion blocks are used to deplete the two-dimensional electron gas in the projection area on the channel layer.
[0048] Specifically, in some embodiments of the present application, a GaN diode is provided, comprising a stacked substrate, a GaN buffer layer, a GaN channel layer, and a GaN barrier layer.
[0049] It can be understood that in this structure, due to the InAlN layer, that is, In 0.17 Al 0.83 N has a piezoelectric polarization effect with the GaN channel layer, and InAlN has a strong spontaneous polarization effect, so a high-density two-dimensional electron gas is generated on the side close to InAlN in the GaN channel layer.
[0050] The electron mobility in this two-dimensional electron gas is very high, which can form a large current.
[0051] Furthermore, an anode region and a cathode region are provided on the InAlN barrier layer. That is, a groove extending to the GaN channel layer is provided on the InAlN barrier layer, so that a portion of the metal of the anode is deposited in the groove to form an ohmic contact with the GaN of the GaN channel layer, and another portion of the metal is deposited on the InAlN barrier layer on both sides of the groove.
[0052] like Figure 2 As shown, a groove is set in the middle of the InAlN barrier layer, and the groove vertically penetrates the InAlN barrier layer downward and extends to the GaN channel layer. Then, a metal layer is deposited in the groove to make ohmic contact with the GaN channel layer below the InAlN barrier layer to form the anode of the device.
[0053] Finally, in an embodiment of the present application, in order to improve the reverse withstand voltage of the diode device, depletion blocks are arranged on both sides of the groove on the InAlN barrier layer, and the depletion blocks are made to contact the anode metal on the InAlN barrier layer, so that the depletion or closure of the two-dimensional electron gas below the depletion block can be controlled by applying a voltage on the anode, that is, the depletion block can be used to deplete the two-dimensional electron gas of the GaN channel layer below it.
[0054] Optionally, in some embodiments of the present application, the anode metal may completely cover the depletion block to achieve effective contact with the depletion block.
[0055] Optionally, in some embodiments, in order to effectively improve the reverse withstand voltage, the depletion region area may be increased, such as Figure 3 As shown, multiple pairs of depletion regions are arranged on both sides of the groove, so that when the device is reverse biased, the 2DEG is broken into several parts, thereby improving the reverse withstand voltage of the device.
[0056] That is, two or more depletion blocks may be arranged on both sides of the groove on the InAlN barrier layer.
[0057] Furthermore, in some embodiments, the depletion block may have a thickness of 30-70 nm and a width of 1-10 um.
[0058] For example, it may be 50 nm, which is not limited in this application.
[0059] It is understandable that the larger the width of the depletion block, the weaker the current capability of the device will be, and the smaller the width, the weaker its current blocking effect will be. That is, in the embodiment of the present application, there is no restriction on the specific size of the depletion block, and it can be flexibly set according to the application scenario of the device.
[0060] Optionally, in some embodiments of the present application, the depletion block is a P-type semiconductor layer, such as P-type InGaN.
[0061] For example, the In content in the P-type InGaN may be between 0.05% and 0.1%, for example, 0.08%, which is not limited in the present application.
[0062] For another example, in some embodiments, the depletion block can be formed by doping InGaN with Mg.
[0063] In some embodiments, the concentration of Mg in the P-type InGaN may be 4E17 / cm -3 -2E19 / cm -3 This application does not impose any restrictions on this.
[0064] Optionally, in other embodiments, the GaN diode and the substrate may be made of materials such as Si, sapphire, or SiC.
[0065] The thickness of the GaN buffer layer may be 3um to 5um, such as 4um;
[0066] The thickness of the GaN channel layer may be 300-700 nm, such as 500 nm;
[0067] The thickness of the InAlN barrier layer may be 10-20 nm, such as 15 nm; the depth of the groove on the GaN channel layer may be 1-10 nm, such as 5 nm.
[0068] It can be understood that the structural dimensions, component ratios, etc. in the above embodiments are merely exemplary and the present application does not impose any limitation thereto.
[0069] It can be understood that in the GaN diode device provided in the embodiment of the present application, when a positive voltage is applied to the anode electrode during operation, the anode metal is in contact with the depletion block (P-InGaN), so that the depletion block is at the same positive voltage. At this time, the depletion effect on the two-dimensional electron gas (2DEG) below is weakened, the 2DEG begins to close, electrons move from the cathode to the anode to form a current, and the diode is turned on in the forward direction.
[0070] Therefore, the turn-on voltage of the diode depends on the degree of depletion of 2DEG by InGaN, that is, on the hole concentration in InGaN.
[0071] It can be understood that in the related art, when electrons reach the groove area, because the anode metal is deposited in the groove area, there will be a potential barrier at the interface between the anode metal in the groove area and the GaN channel layer, which will prevent the electrons from continuing to flow to the anode metal. In the groove etching process, if the etched interface is rough, a large number of interface states will appear, causing the electron transition probability to increase, resulting in a decrease in the forward turn-on voltage, but an increase in reverse leakage and a decrease in reverse withstand voltage.
[0072] In the present application, since the anode metal in the groove area directly forms an ohmic contact with the GaN layer, the potential barrier of the ohmic contact can be ignored, that is, the turn-on voltage depends entirely on the depletion of the 2DEG below by InGaN, so that even if the groove etching interface has a high roughness, it does not affect the forward turn-on of the device.
[0073] Correspondingly, when reverse biased, that is, when a positive voltage is applied to the cathode, the electrons coming from the anode metal will pass through 2DEG and reach the cathode, forming a reverse leakage current.
[0074] In the present application, since the 2DEG below the P-InGaN is in a depleted state, the 2DEG is disconnected and does not form a current path, so the device can withstand a very high reverse withstand voltage. That is, the structure of the depletion block of the present application does not lead to a reduction in reverse withstand voltage.
[0075] That is, due to the novel groove device proposed in the present application, its reverse withstand voltage is determined by the depletion effect of P-InGaN and does not depend on the interface barrier between the anode metal and GaN.
[0076] It can be understood that in the related art, the common groove type SBD relies on the Schottky barrier formed at the interface between the anode metal and GaN to withstand the reverse withstand voltage. In contrast, the novel groove type SBD structure proposed in the present invention has significantly improved reverse withstand voltage.
[0077] That is, for the GaN diode of the embodiment of the present application, the hole concentration in InGaN affects the forward and reverse characteristics of the device. To achieve the best SBD characteristics (low forward turn-on voltage, high reverse withstand voltage), the more Mg is doped in InGaN, the higher the hole concentration, the higher the forward turn-on voltage, and the higher the reverse withstand voltage.
[0078] In some embodiments, in order to achieve both low forward turn-on voltage and high reverse withstand voltage, the amount of Mg doping can be controlled to a relatively small level (such as 3E18 / cm-3) when growing InGaN to form weak P-type InGaN, weakening the depletion effect of InGaN on 2DEG, thereby reducing the turn-on voltage. At the same time, the area of the depletion region can be increased, for example, more depletion regions are provided, so that when the device is reverse biased, the 2DEG is broken into several parts, thereby improving the reverse withstand voltage of the device.
[0079] On the other hand, in some embodiments of the present application, a method for manufacturing a GaN diode is provided.
[0080] Figure 4 The figure is a flow chart of a method for manufacturing a GaN diode. As shown in the figure, the manufacturing method may specifically include the following steps:
[0081] S11, epitaxially growing a GaN buffer layer, a GaN channel layer and an InAlN barrier layer in sequence on a substrate, so that a two-dimensional electron gas is formed on a side of the GaN buffer layer close to the InAlN barrier layer.
[0082] Specifically, the substrate is placed in a MOCVD device, and a GaN buffer layer (thickness is 3-5um, specifically 4um), a GaN channel layer (thickness is 300-700nm, specifically 500nm), and an In0.17Al0.83N layer (thickness is 10-20nm, specifically 15nm) are epitaxially grown in sequence.
[0083] The substrate can be made of Si, sapphire, SiC and other materials.
[0084] It can be understood that due to the piezoelectric polarization effect between the In0.17Al0.83N layer and the GaN channel layer, and the strong spontaneous polarization effect of In0.17Al0.83N, a high-density two-dimensional electron gas will be generated on the side close to InAlN in the GaN channel layer. The electron mobility in the two-dimensional electron gas is very high, that is, a large current can be formed.
[0085] This structure can be suitable for making high-power GaN SBD devices.
[0086] S12, growing a SiO2 layer on the top of the InAlN barrier layer, and removing the SiO2 layer in a target area, where the target area is used to deposit a depletion block, and at least two target areas are arranged on the top of the InAlN barrier layer.
[0087] Specifically, a layer of SiO2 with a thickness of 100 nm can be grown on the surface of InAlN using PECVD equipment, and then SiO2 in the target area can be removed by photolithography and etching, while SiO2 is retained in other areas.
[0088] S13, depositing a depletion block on the target area to deplete the two-dimensional electron gas in the projection area on the channel layer.
[0089] Specifically, Figure 4 As shown, after the wafer is cleaned, it is put back into the MOCVD equipment to epitaxially grow a layer of P-InGaN.
[0090] It can be understood that the P-InGaN is formed by doping Mg in the process of growing InGaN to form a P-type semiconductor, which depletes the 2DEG below it. After the 2DEG below it is depleted, it is equivalent to the two-dimensional electron gas being disconnected, and no current path is formed.
[0091] The thickness of InGaN may be 50 nm, and the composition of In may be between 0.05% and 0.1%, and may be specifically 0.08%.
[0092] It can be understood that the amount of Mg doped in InGaN directly determines the degree of depletion of the two-dimensional electron gas in the depletion region. The specific doping concentration of the present application is not limited and can be flexibly adjusted according to actual conditions.
[0093] It can also be understood that the InGaN has a good lattice match with the underlying InAlN, and the interface formed by InGaN / InAlN has good quality and fewer interface states.
[0094] Furthermore, after the P-InGaN growth is completed, the wafer is placed in an HF acid solution to remove the SiO2, and the InGaN above it will also be removed, leaving only the InGaN in a specific area, as shown in Figure 5 below.
[0095] Finally, the wafer can be annealed in a N2 environment at 800°C for 10 min to activate the Mg in InGaN and increase the hole concentration in the P-type InGaN.
[0096] S14, etching a groove in the anode region on the top of the InAlN barrier layer, so that the groove penetrates the InAlN barrier layer and extends to the GaN channel layer, and the groove is located between the two target regions.
[0097] Specifically, Figure 4 As shown, a groove is etched in the anode region, and an ICP device is used to etch away the InAlN barrier layer, and then the etching is continued downward by 1-10 nm, and specifically, the etching depth can be continued downward by 5 nm.
[0098] S15, depositing an anode metal in the groove, so that the anode metal covers the depletion block and forms an ohmic contact with the GaN of the GaN channel layer.
[0099] Specifically, an anode metal (ie, an anode electrode) is deposited in the anode region, and the metal may be a Ti / Al structure. The anode metal fills the groove and needs to cover the InAlGaN surface.
[0100] Furthermore, after N2 annealing at 550° C. for 5 min, an ohmic contact is formed between the anode metal and GaN.
[0101] S16, etching the cathode regions on both sides of the anode region on the top of the InAlN barrier layer to form a recess, and depositing cathode metal in the recess.
[0102] Specifically, Figure 4 As shown, an ICP device is used to etch the cathode region, and then a cathode metal (i.e., cathode electrode) is deposited. The cathode metal can also be a TiN / Al combination. The new groove-type GaN Schottky diode is thus manufactured.
[0103] It can be understood that the GaN diode and its manufacturing method provided in the present application form an InAlN / GaN heterostructure by adopting an InAlN barrier layer and a GaN channel layer, and deposit an anode metal by adopting a groove structure, and form an ohmic contact with GaN in the groove, and then set depletion blocks in contact with the anode metal on both sides of the groove on the InAlN barrier layer, so that the anode voltage can directly control the depletion and closure of the two-dimensional electron gas of the GaN channel layer, so that when a reverse voltage is applied to the GaN diode device, the depletion block can be controlled to deplete the two-dimensional electron gas, so that the two-dimensional electron gas is in a disconnected state and cannot form a current path, thereby improving the reverse withstand voltage of the GaN diode device; when a forward voltage is applied to the GaN diode device, the depletion effect of the depletion block on the 2DEG below is weakened, the two-dimensional electron gas begins to close, the electrons move from the cathode to the anode to form a current, and the diode is turned on in the forward direction. That is, due to the arrangement of the above-mentioned diode structure, the turn-on voltage of the diode depends on the degree of depletion of the 2DEG by the depletion block, that is, it depends on the hole concentration in the depletion block, and the reverse withstand voltage also depends on the degree of depletion of the 2DEG by the depletion block, and has nothing to do with the interface barrier between the anode metal and GaN, so that even if there are a large number of interface states in the etching process of the groove, the forward turn-on voltage and reverse withstand voltage of the device are not affected. Therefore, the GaN diode device provided by the present application effectively improves the reverse withstand voltage on the basis of ensuring a lower forward turn-on voltage, making the process window larger, and has potential application prospects.
[0104] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0105] The principles and implementation methods of the present invention are described in this article using specific examples. The description of the above embodiments is only used to help understand the method and core idea of the present invention. At the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.
Claims
1. A GaN diode, characterized in that: The GaN comprises: A stacked substrate, a GaN buffer layer, a GaN channel layer and an InAlN barrier layer; Wherein, a two-dimensional electron gas is formed on one side of the GaN buffer layer close to the InAlN barrier layer; An anode region and cathode regions located on both sides of the anode region are arranged on the top of the InAlN barrier layer, and a portion of metal of the anode region is arranged in a groove penetrating the InAlN barrier layer and forms an ohmic contact with the GaN channel layer; Depletion blocks are deposited on the top of the InAlN barrier layer on both sides of the groove, the depletion blocks are in contact with the metal of the anode region on the InAlN barrier layer, and the depletion blocks are used to deplete the two-dimensional electron gas in the projection area on the channel layer.
2. The GaN diode according to claim 1, characterized in that: The anode metal on top of the InAlN barrier layer covers the depletion block.
3. The GaN diode according to claim 1, characterized in that: Two or more pairs of depletion blocks are arranged on the top of the InAlN barrier layer.
4. The GaN diode according to claim 1, characterized in that: The depletion block has a thickness of 30-70 nm and a width of 1-10 um.
5. The GaN diode according to claim 1, characterized in that: The depletion block is P-type InGaN.
6. The GaN diode according to claim 5, characterized in that: P-type InGaN is doped with Mg, and the concentration of Mg is 4E17 / cm -3 -2E19 / cm -3 .
7. The GaN diode according to claim 5, characterized in that: The composition of In in the P-type InGaN is 0.05-0.1%.
8. The GaN diode according to any one of claims 1 to 7, characterized in that: The composition of InAlN in the InAlN barrier layer is In 0.17 Al 0.83 N.
9. The GaN diode according to any one of claims 1 to 7, characterized in that: The thickness of the GaN buffer layer is 3um-5um; the thickness of the GaN channel layer is 300-700nm; the thickness of the InAlN barrier layer is 10-20nm; and the depth of the groove on the GaN channel layer is 1-10nm.
10. A method for manufacturing a GaN diode, characterized in that: The method comprises: Epitaxially growing a GaN buffer layer, a GaN channel layer and an InAlN barrier layer in sequence on a substrate, so that a two-dimensional electron gas is formed on a side of the GaN buffer layer close to the InAlN barrier layer; Growing a SiO2 layer on top of the InAlN barrier layer and removing the SiO2 layer in a target area, wherein the target area is used for depositing a depletion block, and at least two target areas are arranged on top of the InAlN barrier layer; Depositing a depletion block on the target area to deplete the two-dimensional electron gas in a projection area on the channel layer; Etching a groove in the anode region on the top of the InAlN barrier layer, so that the groove penetrates the InAlN barrier layer and extends to the GaN channel layer, and the groove is located between the two target regions; Depositing an anode metal in the groove so that the anode metal covers the depletion block and forms an ohmic contact with GaN of the GaN channel layer; The cathode regions on both sides of the anode region on the top of the InAlN barrier layer are etched to form recesses, and cathode metal is deposited in the recesses.