CN112768512A - AlGaN-based double-channel Schottky diode based on groove anode structure and preparation method - Google Patents
AlGaN-based double-channel Schottky diode based on groove anode structure and preparation method Download PDFInfo
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- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
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- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
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- H01L29/00—Semiconductor devices adapted for rectifying, amplifying, oscillating or switching, or capacitors or resistors with at least one potential-jump barrier or surface barrier, e.g. PN junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
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- H01L29/6609—Diodes
- H01L29/66143—Schottky diodes
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- H01L29/861—Diodes
- H01L29/872—Schottky diodes
Abstract
The invention relates to an AlGaN-based double-channel Schottky diode based on a groove anode structure and a preparation method thereof, wherein the diode comprises: the substrate, the buffer layer, the channel layer, the first barrier layer, the superlattice layer, the second barrier layer and the GaN cap layer are sequentially stacked from bottom to top, wherein a first conductive channel is formed between the channel layer and the first barrier layer, and a second conductive channel is formed between the superlattice layer and the second barrier layer; the anode is arranged on the GaN cap layer, the bottom of the anode sequentially penetrates through the GaN cap layer and the second barrier layer and is positioned in the superlattice layer, and the anode and the superlattice layer form Schottky contact; and the cathode is arranged on the GaN cap layer and surrounds the periphery of the anode, a space exists between the cathode and the anode, and the cathode and the GaN cap layer form ohmic contact. According to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the conductive channel is added, the electron concentration is further improved, and the on-resistance is reduced.
Description
Technical Field
The invention belongs to the technical field of semiconductor devices, and particularly relates to an AlGaN-based double-channel Schottky diode based on a groove anode structure and a preparation method thereof.
Background
A GaN Schottky Barrier Diode (SBD) is an important GaN power device. Because GaN is a multi-sub device, the minority carrier charge storage effect is very weak, when the device is switched off, only the displacement current caused by the junction capacitance is generated, and compared with the reverse recovery storage charge generated by a p-n junction diode, the charge transmitted by the displacement current can be almost ignored, so that the switching loss of the SBD device can be reduced.
Since GaN SBD devices have so many advantages, much research has been conducted on them. In order to realize the GaN SBD device, there are several manufacturing methods, and a more common method is to deposit a cathode of ohmic contact and an anode of schottky contact on the top layer of GaN, respectively, and control the switching of the SBD by controlling the conduction of the two-dimensional electron gas through the anode voltage, as shown in fig. 1. At present, much effort is made to develop GaN schottky diode devices based on the structure, and most of the research is staying at a simple structure using a single channel, namely, two-dimensional electron gas conduction generated by using only an AlGaN/GaN heterojunction.
The GaN Schottky diode with the structure has a plurality of problems in the using process. For example: in the high-temperature working process of the AlGaN/GaN heterojunction, two-dimensional electron gas is easy to overflow towards the substrate, so that the forward current density is greatly reduced, and the reverse leakage is increased. The GaN channel layer has a finite breakdown field strength and a breakdown voltage inferior to that of a device using the AlGaN layer as its conductive channel. The SBD device directly adopting the AlGaN alloy channel greatly reduces the mobility of the AlGaN/GaN heterostructure due to the influence of alloy disordered scattering, and greatly limits the application of the GaN Schottky diode in the field of power electronics.
Disclosure of Invention
In order to solve the problems in the prior art, the invention provides an AlGaN-based double-channel Schottky diode based on a groove anode structure and a preparation method thereof. The technical problem to be solved by the invention is realized by the following technical scheme:
the invention provides an AlGaN-based double-channel Schottky diode based on a groove anode structure, which comprises:
the substrate, the buffer layer, the channel layer, the first barrier layer, the superlattice layer, the second barrier layer and the GaN cap layer are sequentially stacked from bottom to top, wherein a first conductive channel is formed between the channel layer and the first barrier layer, and a second conductive channel is formed between the superlattice layer and the second barrier layer;
the anode is arranged on the GaN cap layer, the bottom of the anode sequentially penetrates through the GaN cap layer and the second barrier layer and is positioned in the superlattice layer, and the anode and the superlattice layer form Schottky contact;
the cathode is arranged on the GaN cap layer and surrounds the periphery of the anode, a space exists between the cathode and the anode, and the cathode and the GaN cap layer form ohmic contact.
In one embodiment of the present invention, a passivation layer is further included, disposed on the uncovered region of the GaN cap layer, and covering a portion of the upper surface of the anode and a portion of the cathode.
In one embodiment of the invention, the device further comprises an interconnection metal arranged in the passivation layer, and the bottom of the interconnection metal is respectively contacted with the upper surfaces of the anode and the cathode.
In one embodiment of the present invention, the substrate is a P-type doped silicon substrate with a thickness of 600-1000 μm.
In one embodiment of the invention, the buffer layer comprises an AlN nucleating layer and Al which are sequentially stacked from bottom to top0.75Ga0.25N layer and Al0.5Ga0.5An N layer, wherein the AlN nucleating layer has a thickness of 150-250nm and the Al layer0.75Ga0.25The thickness of the N layer is 450-550nm, and the Al layer0.5Ga0.5The thickness of the N layer is 450-550 nm.
In one embodiment of the present invention, the channel layer is Al0.1Ga0.9And the N channel layer is 2-3 mu m thick.
In one embodiment of the invention, the first barrier layer is an AlN barrier layer with a thickness of 2-5nm, and the second barrier layer is Al0.4Ga0.6And the N barrier layer is 25-30nm thick.
In one embodiment of the invention, the superlattice layer comprises a GaN layer and an AlN layer which are periodically arranged from bottom to top, wherein the arrangement period is 18-22, the GaN layer is positioned on the first barrier layer, the thickness of the GaN layer is 5nm, and the thickness of the AlN layer is 1 nm.
In one embodiment of the invention, the length of the anode covering the GaN cap layer is 0.5-2 μm, and the distance between the cathode and the anode is 5-30 μm.
The invention provides a preparation method of an AlGaN-based double-channel Schottky diode based on a groove anode structure, which is suitable for the AlGaN-based double-channel Schottky diode based on the groove anode structure in any embodiment and comprises the following steps:
s1: sequentially epitaxially growing an AlGaN buffer layer, an AlGaN channel layer, an AlN barrier layer, a superlattice layer, an AlGaN barrier layer and a GaN cap layer on a P-type doped Si substrate to obtain a Si-based GaN epitaxial material, wherein the superlattice layer comprises a GaN layer and an AlN layer which are periodically arranged from bottom to top;
s2: etching the Si-based GaN epitaxial material to form mutually isolated MESA active regions;
s3: sequentially depositing Ti metal, Al metal, Ni metal and Au metal on the GaN cap layer to form a cathode, and performing annealing treatment to enable the cathode to form ohmic contact with the GaN cap layer;
s4: sequentially etching the GaN cap layer, the AlGaN barrier layer, and the GaN layer and the AlN layer in at least one period to obtain an anode groove;
s5: sequentially depositing Ni metal and Au metal in the anode groove to form an anode, and performing annealing treatment to enable the anode to form Schottky contact with the superlattice layer;
s6: depositing Al on the substrate in sequence2O3Layer and SiO2A layer as a passivation layer;
s7: and etching the passivation layer to form an interconnection through hole, and depositing Ni metal and Au metal in the interconnection through hole in sequence to form interconnection metal.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the first conductive channel is formed between the channel layer and the first barrier layer, the second conductive channel is formed between the superlattice layer and the second barrier layer, so that the conductive channels are increased, the electron concentration is further improved, and the on-resistance is reduced;
2. according to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the anode is in direct contact with the two-dimensional electron gas at the second conductive channel, so that the starting voltage can be reduced, and the forward conduction current can be improved;
3. according to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the superlattice layer is adopted to replace the traditional AlGaN alloy channel layer, so that alloy disordered scattering is effectively reduced, the mobility of two-dimensional electron gas at the position of a conductive channel is improved, the on-resistance is reduced, and the high-voltage resistance characteristic of the AlGaN channel is kept;
4. according to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the first barrier layer is used as a back barrier of the upper heterojunction, so that the problem of two-dimensional electron gas overflow of a device in a high-temperature environment is solved, the high-temperature characteristic of the device is improved, and the on-resistance is reduced.
The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic structural diagram of a conventional GaN schottky diode;
fig. 2 is a schematic structural diagram of an AlGaN based double channel schottky diode based on a recessed anode structure according to an embodiment of the present invention;
fig. 3 is a flowchart of a method for manufacturing an AlGaN based double channel schottky diode based on a recessed anode structure according to an embodiment of the present invention;
fig. 4a to fig. 4h are flow charts of processes for manufacturing an AlGaN based dual channel schottky diode based on a recessed anode structure according to an embodiment of the present invention.
Icon: 1-a substrate; 2-a buffer layer; 3-a channel layer; 4-a first barrier layer; 5-a superlattice layer; 6-a second barrier layer; a 7-GaN cap layer; 8-an anode; 9-a cathode; 10-a passivation layer; 11-interconnect metal.
Detailed Description
To further illustrate the technical means and effects of the present invention adopted to achieve the predetermined objects, the following detailed description is provided with reference to the accompanying drawings and the detailed description to provide an AlGaN-based dual channel schottky diode based on a recessed anode structure and a method for manufacturing the same.
The foregoing and other technical matters, features and effects of the present invention will be apparent from the following detailed description of the embodiments, which is to be read in connection with the accompanying drawings. The technical means and effects of the present invention adopted to achieve the predetermined purpose can be more deeply and specifically understood through the description of the specific embodiments, however, the attached drawings are provided for reference and description only and are not used for limiting the technical scheme of the present invention.
Example one
Referring to fig. 2, fig. 2 is a schematic structural diagram of an AlGaN based double channel schottky diode based on a recessed anode structure according to an embodiment of the present invention. As shown in the figure, the AlGaN based double channel schottky diode based on the recessed anode structure of the present embodiment includes: the substrate 1, the buffer layer 2, the channel layer 3, the first barrier layer 4, the superlattice layer 5, the second barrier layer 6, the GaN cap layer 7, the anode 8 and the cathode 9. The substrate 1, the buffer layer 2, the channel layer 3, the first barrier layer 4, the superlattice layer 5, the second barrier layer 6 and the GaN cap layer 7 are sequentially stacked from bottom to top. The anode 8 is arranged on the GaN cap layer 7, and the bottom of the anode sequentially penetrates through the GaN cap layer 7 and the second barrier layer 6 and is positioned in the superlattice layer 5. The cathode 9 is arranged on the GaN cap layer 7 and surrounds the periphery of the anode 8, and a distance is reserved between the cathode 9 and the anode 8.
In this embodiment, the first barrier layer 4 serves as a back barrier layer of the superlattice layer 5, a first conduction channel is formed between the first barrier layer 4 and the channel layer 3, and a second conduction channel is formed between the superlattice layer 5 and the second barrier layer 6. The anode 8 forms a schottky contact with the superlattice layer 5; the cathode 9 forms an ohmic contact with the GaN cap layer 7.
The AlGaN-based double-channel Schottky diode based on the groove anode structure is provided with two conducting channels, so that the conducting channels are increased, the electron concentration is further improved, and the on-resistance is reduced; in addition, the anode is in direct contact with the two-dimensional electron gas at the second conductive channel, so that the starting voltage can be reduced, and the forward conduction current can be improved.
Further, the AlGaN based double channel schottky diode based on the groove anode structure further includes a passivation layer 10 and an interconnection metal 11, wherein the passivation layer 10 is disposed on the GaN cap layer 7 at an uncovered region and covers a portion of the upper surface of the anode 8 and a portion of the cathode 9. An interconnect metal 11 is disposed within the passivation layer 10 with its bottom in contact with the upper surfaces of the anode 8 and cathode 9, respectively.
Optionally, the substrate 1 is a P-type doped silicon substrate with a thickness of 600-.
In this embodiment, the buffer layer 2 includes an AlN nucleation layer and Al stacked in this order from bottom to top0.75Ga0.25N layer and Al0.5Ga0.5And N layers. Optionally, the AlN nucleation layer has a thickness of 150-250nm and Al0.75Ga0.25The thickness of the N layer is 450-550nm, Al0.5Ga0.5The thickness of the N layer is 450-550 nm.
In the present embodiment, the channel layer 3 is Al0.1Ga0.9And the N channel layer is 2-3 mu m thick.
Optionally, the first barrier layer 4 is an AlN barrier layer with a thickness of 2-5nm, and the second barrier layer 6 is Al0.4Ga0.6And the N barrier layer is 25-30nm thick.
In this embodiment, the AlN barrier layer serves as a back barrier layer of the superlattice layer 5 and is in contact with the lower layer Al0.1Ga0.9The N channel layer forms a heterojunction, the problem of two-dimensional electron gas overflow of the device in a high-temperature environment is avoided, the high-temperature characteristic of the device is improved, and the on-resistance is reduced.
Further, the superlattice layer 5 includes a GaN layer and an AlN layer periodically arranged from bottom to top, wherein the arrangement period is 18 to 22, the GaN layer is located on the first barrier layer 4, the thickness of the GaN layer is 5nm, and the thickness of the AlN layer is 1 nm. Preferably, the anode 8 is located within the superlattice layer 5 to a depth of 5-10 nm.
Optionally, the GaN cap layer 7 has a thickness of 2-4nm
Alternatively, the length of the anode 8 covering the GaN cap layer 7 is 0.5-2 μm, and the distance between the cathode 9 and the anode 8 is 5-30 μm.
In the present embodiment, the anode 8 includes Ni and Au metals stacked from bottom to top, and the thicknesses of the metal layers are 45nm and 200nm, respectively; the cathode 9 comprises Ti, Al, Ni and Au metals which are stacked from bottom to top, and the thicknesses of the metal layers are respectively 20nm, 140nm, 45nm and 55 nm.
In this embodiment, the passivation layer includes Al stacked from bottom to top2O3Layer and SiO2Layer, optionally, Al2O3The thickness of the layer was 3nm, SiO2The thickness of the layer was 800 nm.
Further, the interconnection metal 11 includes Ni and Au metals stacked from bottom to top, and the thicknesses of the respective metal layers are 40nm and 500nm, respectively.
According to the AlGaN-based double-channel Schottky diode based on the groove anode structure, the superlattice layer is adopted to replace a traditional AlGaN alloy channel layer, alloy disordered scattering is effectively reduced, the mobility of two-dimensional electron gas at the position of a conducting channel is improved, the on-resistance is reduced, and meanwhile the high-voltage resistance characteristic of the AlGaN channel is kept.
Example two
The embodiment provides a method for preparing an AlGaN based double channel schottky diode based on a groove anode structure, and is suitable for the AlGaN based double channel schottky diode based on the groove anode structure in the embodiment. Referring to fig. 3, fig. 3 is a flowchart of a method for manufacturing an AlGaN based dual channel schottky diode based on a recessed anode structure according to an embodiment of the present invention. As shown in the figure, the method of the present embodiment includes:
s1: sequentially epitaxially growing an AlGaN buffer layer, an AlGaN channel layer, an AlN barrier layer, a superlattice layer, an AlGaN barrier layer and a GaN cap layer on a P-type doped Si substrate to obtain a Si-based GaN epitaxial material, wherein the superlattice layer comprises a GaN layer and an AlN layer which are periodically arranged from bottom to top;
s2: etching the Si-based GaN epitaxial material to form mutually isolated MESA active regions;
s3: sequentially depositing Ti metal, Al metal, Ni metal and Au metal on the GaN cap layer to form a cathode, and performing annealing treatment to enable the cathode to form ohmic contact with the GaN cap layer;
s4: sequentially etching the GaN cap layer, the AlGaN barrier layer, and the GaN layer and the AlN layer in at least one period to obtain an anode groove;
s5: sequentially depositing Ni metal and Au metal in the anode groove to form an anode, and carrying out annealing treatment to enable the anode to form Schottky contact with the superlattice layer;
s6: depositing Al on the substrate in sequence2O3Layer and SiO2A layer as a passivation layer;
s7: and etching the passivation layer to form an interconnection through hole, and sequentially depositing Ni metal and Au metal in the interconnection through hole to form interconnection metal.
Further, please refer to fig. 4a to fig. 4h in combination to specifically describe the manufacturing method of the present embodiment, and fig. 4a to fig. 4h are flow charts of a manufacturing process of an AlGaN-based double channel schottky diode based on a recessed anode structure according to an embodiment of the present invention. Specifically, the method of the embodiment includes:
By adopting a metal organic chemical vapor deposition process, an AlGaN buffer layer 402, an AlGaN channel layer 403, an AlN barrier layer 404, a superlattice layer 405, an AlGaN barrier layer 406, and a GaN cap layer 407 are sequentially extended on a P-type doped Si substrate 401, so as to obtain a Si-based GaN epitaxial material, as shown in fig. 4 a.
In this embodiment, the AlGaN buffer layer 402 includes an AlN nucleation layer and Al stacked from bottom to top0.75Ga0.25N layer and Al0.5Ga0.5And N layers. The AlGaN channel layer 403 is Al0.1Ga0.9And N layers. The superlattice layer 405 includes GaN layers and AlN layers periodically arranged from bottom to top, wherein the arrangement period is 20, the GaN layers are located on the AlN barrier layer 404, the thickness of the GaN layers is 5nm, and the thickness of the AlN layers is 1 nm. AlGaN barrier layer 406 is Al0.4Ga0.6And N layers.
And 2, forming mutually isolated MESA active regions on the Si-based GaN epitaxial material.
By adopting photoetching and inductively coupled plasma etching processes, mutually isolated MESA active regions are formed on the Si-based GaN epitaxial material, and the MESA steps are etched until the AlGaN buffer layer 402 stops, so that all two-dimensional electron gas is blocked, as shown in FIG. 4 b.
And 3, adopting organic cleaning, sequentially and respectively ultrasonically cleaning the sample in the step 2 in acetone, isopropanol and deionized water for 3min, and then cleaning in a TMAH (tetra methyl ammonium hydroxide) water bath at 85 ℃ for 10 min.
Depositing Ti metal with the thickness of 20nm, Al metal with the thickness of 140nm, Ni metal with the thickness of 45nm and Au metal with the thickness of 55nm on the GaN cap layer 7 of the MESA active region in sequence to form a cathode electrode 408 by adopting photoetching and electron beam evaporation processes; followed by an anneal for 45s at 865 c in a nitrogen ambient to form the cathode electrode 408 in ohmic contact with the GaN cap layer 407, as shown in figure 4 c.
And etching the GaN cap layer 407, the AlGaN barrier layer 406 and the GaN layer and the AlN layer on the top of the superlattice layer 405 for one period in sequence by adopting a two-step inductively coupled plasma etching process to obtain an anode groove 409 as shown in FIG. 4 d.
The specific etching process parameters are as follows: the first etching step uses Cl2/BCl3As etching gas, inductively coupled plasma etching is used, in which Cl is present2/BCl3The gas flow rates of (a) and (b) are 10sccm and 25sccm, respectively, and the RF and ICP powers are 50W and 100W, respectively. The second etching step uses BCl with a gas flow of 25sccm3As an etching gas, inductively coupled plasma etching was employed, in which RF and ICP powers were 0W and 55W, respectively.
Adopting photoetching and electron beam evaporation processes to sequentially deposit Ni metal with the thickness of 45nm and Au metal with the thickness of 200nm in the anode groove 409 to form an anode electrode 410; followed by an anneal in a nitrogen ambient at 400 c for 5min to form a schottky contact between the anode electrode 410 and the superlattice layer 405 as shown in fig. 4 e.
Depositing Al with a thickness of 3nm on the whole substrate by ALD process2O3A layer; then adopting PECVD process on Al2O3Growing SiO with thickness of 800nm on the layer2Layer of Al2O3Layer and SiO2The layer serves as a passivation layer 411 as shown in fig. 4 f.
And 8, manufacturing the interconnection through hole.
An ion beam etching process is used to etch the interconnect via on the passivation layer 411 to reach the cathode and the anode, as shown in fig. 4 g.
Step 9, an interconnect metal 412 is fabricated.
An interconnection metal 412 consisting of a Ni metal with a thickness of 40nm and an Au metal with a thickness of 500nm is sequentially deposited in the interconnection via holes by using photolithography and electron beam evaporation processes, as shown in FIG. 4 h.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that an article or device that comprises a list of elements does not include only those elements but may include other elements not expressly listed. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of additional like elements in the article or device comprising the element. The terms "connected" or "coupled" and the like are not restricted to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The directional or positional relationships indicated by "upper", "lower", "left", "right", etc., are based on the directional or positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (10)
1. The utility model provides an AlGaN base double channel schottky diode based on recess anode structure which characterized in that includes:
the substrate, the buffer layer, the channel layer, the first barrier layer, the superlattice layer, the second barrier layer and the GaN cap layer are sequentially stacked from bottom to top, wherein a first conductive channel is formed between the channel layer and the first barrier layer, and a second conductive channel is formed between the superlattice layer and the second barrier layer;
the anode is arranged on the GaN cap layer, the bottom of the anode sequentially penetrates through the GaN cap layer and the second barrier layer and is positioned in the superlattice layer, and the anode and the superlattice layer form Schottky contact;
the cathode is arranged on the GaN cap layer and surrounds the periphery of the anode, a space exists between the cathode and the anode, and the cathode and the GaN cap layer form ohmic contact.
2. The AlGaN-based dual channel schottky diode according to claim 1, further comprising a passivation layer disposed on the GaN cap layer at the uncovered region and an upper surface covering a portion of the anode and a portion of the cathode.
3. The AlGaN-based double channel schottky diode according to claim 2, further comprising an interconnection metal disposed in the passivation layer, the bottom portions of which are in contact with the upper surfaces of the anode and the cathode, respectively.
4. The AlGaN-based double-channel Schottky diode as recited in claim 1, wherein the substrate is a P-type doped silicon substrate with a thickness of 600-1000 μm.
5. The AlGaN-based double-channel Schottky diode based on the groove anode structure as claimed in claim 1, wherein the buffer layer comprises an AlN nucleation layer and Al which are sequentially stacked from bottom to top0.75Ga0.25N layer and Al0.5Ga0.5An N layer, wherein the AlN nucleating layer has a thickness of 150-250nm, and the Al layer0.75Ga0.25The thickness of the N layer is 450-550nm, and the Al layer0.5Ga0.5The thickness of the N layer is 450-550 nm.
6. According to claim1 the AlGaN-based double-channel Schottky diode based on the groove anode structure is characterized in that the channel layer is Al0.1Ga0.9And the N channel layer is 2-3 mu m thick.
7. The AlGaN-based double channel Schottky diode of claim 1 wherein said first barrier layer is an AlN barrier layer having a thickness of 2-5nm and said second barrier layer is Al0.4Ga0.6And the N barrier layer is 25-30nm thick.
8. The AlGaN-based dual channel schottky diode according to claim 1, wherein the superlattice layer includes a GaN layer and an AlN layer periodically disposed from bottom to top, wherein a period is 18 to 22, the GaN layer is disposed on the first barrier layer, a thickness of the GaN layer is 5nm, and a thickness of the AlN layer is 1 nm.
9. The AlGaN based double channel schottky diode according to claim 1, wherein the anode covers the GaN cap layer with a length of 0.5-2 μm, and the cathode is spaced apart from the anode by 5-30 μm.
10. A method for manufacturing an AlGaN based double channel schottky diode based on a recessed anode structure, which is suitable for the AlGaN based double channel schottky diode based on a recessed anode structure according to any one of claims 1 to 9, and includes:
s1: sequentially epitaxially growing an AlGaN buffer layer, an AlGaN channel layer, an AlN barrier layer, a superlattice layer, an AlGaN barrier layer and a GaN cap layer on a P-type doped Si substrate to obtain a Si-based GaN epitaxial material, wherein the superlattice layer comprises a GaN layer and an AlN layer which are periodically arranged from bottom to top;
s2: etching the Si-based GaN epitaxial material to form mutually isolated MESA active regions;
s3: sequentially depositing Ti metal, Al metal, Ni metal and Au metal on the GaN cap layer to form a cathode, and performing annealing treatment to enable the cathode to form ohmic contact with the GaN cap layer;
s4: sequentially etching the GaN cap layer, the AlGaN barrier layer, and the GaN layer and the AlN layer in at least one period to obtain an anode groove;
s5: sequentially depositing Ni metal and Au metal in the anode groove to form an anode, and performing annealing treatment to enable the anode to form Schottky contact with the superlattice layer;
s6: depositing Al on the substrate in sequence2O3Layer and SiO2A layer as a passivation layer;
s7: and etching the passivation layer to form an interconnection through hole, and depositing Ni metal and Au metal in the interconnection through hole in sequence to form interconnection metal.
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