Schottky Barrier Diode and Its Preparation Method and Application

Abstract

The present application relates to a Schottky barrier diode, a preparation method thereof and an application. The Schottky barrier diode includes: a substrate, an AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer and an AlGaN barrier layer which are sequentially stacked on the substrate; the content of In in the InGaN back barrier layer gradually increases in the direction away from the substrate. In the above-mentioned Schottky barrier diode, the InGaN back barrier layer with the content of In gradually increasing in the direction away from the substrate can effectively suppress the short-channel effect of the GaN buffer layer, and the InGaN back barrier layer can form a relatively high back barrier for the GaN channel layer, which is beneficial to improving the localization of the two-dimensional electron gas, can inhibit the overflow of the two-dimensional electrons in the channel to the buffer layer, and enables the electrical performance of the Schottky barrier diode to have better stability.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor devices, and particularly to a Schottky barrier diode, a preparation method thereof, and an application thereof. Background Art

[0002] A Schottky barrier diode, also known as a hot carrier diode, is made using the metal-semiconductor contact characteristic. Due to its advantages such as a low turn-on voltage, a specific on-resistance, a low reverse leakage current, and a high breakdown voltage, the Schottky barrier diode is widely used in various electronic products. Among them, since gallium nitride (GaN) has a large bandgap width and a high electron mobility, the GaN-based Schottky barrier diode has both good performance and low cost, making it more widely concerned compared with Schottky barrier diodes of other systems. However, the traditional GaN-based Schottky barrier diode has the defect of poor stability. Summary of the Invention

[0003] Based on this, it is necessary to provide a Schottky barrier diode, a preparation method thereof, and an application thereof, which have good stability.

[0004] In a first aspect, the present application provides a Schottky barrier diode, including:

[0005] A substrate, an AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer, and an AlGaN barrier layer sequentially stacked on the substrate; the content of In in the InGaN back barrier layer gradually increases in the direction away from the substrate.

[0006] In some embodiments, the thickness of the AlN nucleation layer is 0.5 nm to 1.5 nm.

[0007] In some embodiments, the thickness of the GaN buffer layer is 200 nm to 400 nm.

[0008] In some embodiments, the thickness of the InGaN back barrier layer is 10 nm to 30 nm.

[0009] In some embodiments, the thickness of the GaN channel layer is 100 nm to 300 nm.

[0010] In some embodiments, the thickness of the AlGaN barrier layer is 10 nm to 30 nm.

[0011] In some embodiments, in the InGaN back barrier layer, calculated by the percentage of the amount of substance of In in the total amount of In and Ga, the amount of substance of In is 1% to 22%.

[0012] In some embodiments, a passivation layer is further included, and the passivation layer is located on the surface of the AlGaN barrier layer away from the substrate.

[0013] In some embodiments, a cathode metal electrode, an anode metal electrode, an upper anode metal field plate, and a side anode metal field plate are further included;

[0014] The cathode metal electrode is located on the surface of the AlGaN barrier layer away from the substrate;

[0015] The upper anode metal field plate is located on the surface of the passivation layer away from the substrate and is spaced apart from the cathode metal electrode;

[0016] The side anode metal field plate is located at the edge of the upper anode metal field plate and penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the side anode metal field plate is in contact with the GaN channel layer;

[0017] The anode metal electrode penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the anode metal electrode is in contact with the GaN channel layer.

[0018] In some embodiments, the thickness of the passivation layer is 40 nm to 80 nm.

[0019] In some embodiments, the width of the cathode metal electrode is 3 μm to 7 μm.

[0020] In some embodiments, the width of the anode metal electrode is 3 μm to 7 μm.

[0021] In some embodiments, the distance between the cathode metal electrode and the anode metal electrode is 15 μm to 25 μm.

[0022] In some embodiments, the thickness of the upper anode metal field plate is 30 nm to 50 nm.

[0023] In some embodiments, the thickness of the side anode metal field plate is 200 nm to 400 nm.

[0024] In some embodiments, the width of the side anode metal field plate is 50 nm to 150 nm.

[0025] In some embodiments, the material of the passivation layer includes Si3N4.

[0026] In some embodiments, the material of the cathode metal electrode includes Ti, Al, Ni, and Au.

[0027] In some embodiments, the material of the anode metal electrode includes Ni and Au.

[0028] In some embodiments, the material of the upper anode metal field plate includes Ni and Au.

[0029] In some embodiments, the material of the side anode metal field plate includes Ni and Au.

[0030] In a second aspect, the present application provides a method for manufacturing a Schottky barrier diode, including:

[0031] Providing a substrate;

[0032] Successively preparing, on the substrate, a stacked AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer, and an AlGaN barrier layer; wherein the content of In in the InGaN back barrier layer gradually increases in a direction away from the substrate.

[0033] In some embodiments, it further includes: respectively preparing a passivation layer and a cathode metal electrode on the surface of the AlGaN barrier layer.

[0034] Respectively preparing an anode metal electrode, an upper anode metal field plate, and a side anode metal field plate on the surface of the passivation layer; the upper anode metal field plate is located on the surface of the passivation layer away from the substrate and is spaced apart from the cathode metal electrode; the side anode metal field plate is located at the edge of the upper anode metal field plate and penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the side anode metal field plate is in contact with the GaN channel layer; the anode metal electrode penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the anode metal electrode is in contact with the GaN channel layer.

[0035] In a third aspect, the present application provides an electronic product, including the Schottky barrier diode of any one of the above or the Schottky barrier diode manufactured by the manufacturing method of the Schottky barrier diode of any one of the above.

[0036] The above Schottky barrier diode includes a substrate, and an AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer, and an AlGaN barrier layer that are successively stacked on the substrate. Among them, the content of In in the InGaN back barrier layer gradually increases in a direction away from the substrate. The InGaN back barrier layer in which the content of In gradually increases in a direction away from the substrate can effectively suppress the short-channel effect of the GaN buffer layer, and this InGaN back barrier layer can form a relatively high back barrier for the GaN channel layer, which is beneficial to improving the locality of the two-dimensional electron gas, can inhibit the overflow of two-dimensional electrons in the channel to the buffer layer, and enables the electrical performance of the Schottky barrier diode to have better stability. Description of the Drawings

[0037] Figure 1 Schematic diagram of the structure of the Schottky barrier diode provided in Embodiment 1 of the present application.

[0038] Description of the reference numerals

[0039] 10. Substrate; 20. AlN nucleation layer; 30. GaN buffer layer; 40. InGaN back barrier layer; 50. GaN channel layer; 60. AlGaN barrier layer; 70. Passivation layer; 80. Side anode metal field plate; 90. Anode metal electrode; 100. Upper anode metal field plate; 110. Cathode metal electrode. Detailed implementation manners

[0040] To make the above objects, features, and advantages of the present application more apparent and understandable, the following detailed description of the specific implementation manners of the present application will be given with reference to the accompanying drawings. Many specific details are set forth in the following description to fully understand the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application. Therefore, the present application is not limited by the specific embodiments disclosed below.

[0041] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0042] Referring to Figure 1 , an embodiment of the present application provides a Schottky barrier diode, including:

[0043] Substrate 10, an AlN nucleation layer 20, a GaN buffer layer 30, an InGaN back barrier layer 40, a GaN channel layer 50, and an AlGaN barrier layer 60 sequentially stacked on the substrate 10; the content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10. The above Schottky barrier diode includes a substrate 10, an AlN nucleation layer 20, a GaN buffer layer 30, an InGaN back barrier layer 40, a GaN channel layer 50, and an AlGaN barrier layer 60 sequentially stacked on the substrate 10, wherein the content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10. The InGaN back barrier layer 40 with the content of In gradually increasing in the direction away from the substrate 10 can effectively suppress the short-channel effect of the GaN buffer layer 30, and the InGaN back barrier layer 40 can form a relatively high back barrier for the GaN channel layer 50, which is beneficial to improving the localization of the two-dimensional electron gas, can inhibit the overflow of two-dimensional electrons in the channel to the buffer layer, and enables the electrical performance of the Schottky barrier diode to have better stability. Further, the InGaN layer with the content of In gradually increasing from bottom to top can, in addition to serving as a back barrier layer, also eliminate the need for compensation dopants such as Fe or C in the Schottky barrier diode.

[0044] Refer again to Figure 1 , in the figure, the x direction is defined as the thickness direction, the z direction is defined as the width direction, and the direction perpendicular to both the x direction and the z direction is the y direction, and the y direction is defined as the length direction.

[0045] In some embodiments, the thickness of the AlN nucleation layer 20 is 0.5 nm to 1.5 nm. Optionally, the thickness of the AlN nucleation layer 20 is 0.5 nm, 0.6 nm, 0.7 nm, 0.8 nm, 0.9 nm, 1.0 nm, 1.1 nm, 1.2 nm, 1.3 nm, 1.4 nm, or 1.5 nm.

[0046] In some embodiments, the thickness of the GaN buffer layer 30 is 200 nm to 400 nm. Optionally, the thickness of the GaN buffer layer 30 is 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, or 400 nm.

[0047] In some embodiments, the thickness of the InGaN back barrier layer 40 is 10 nm to 30 nm. Optionally, the thickness of the InGaN back barrier layer 40 is 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, or 30 nm.

[0048] In some embodiments, the thickness of the GaN channel layer 50 is 100 nm to 300 nm. Optionally, the thickness of the GaN channel layer 50 is 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, 150 nm, 160 nm, 170 nm, 180 nm, 190 nm, 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, or 300 nm.

[0049] In some embodiments, the thickness of the AlGaN barrier layer 60 is 10 nm to 30 nm. Optionally, the thickness of the AlGaN barrier layer 60 is 10 nm, 11 nm, 12 nm, 13 nm, 14 nm, 15 nm, 16 nm, 17 nm, 18 nm, 19 nm, 20 nm, 21 nm, 22 nm, 23 nm, 24 nm, 25 nm, 26 nm, 27 nm, 28 nm, 29 nm, or 30 nm.

[0050] In some embodiments, in the InGaN back barrier layer 40, the molar amount of In is 1% to 22% in terms of the percentage of the total molar amount of In and Ga. Optionally, in the InGaN back barrier layer 40, the molar amount of In is 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, or 22% in terms of the percentage of the total molar amount of In and Ga.

[0051] In some embodiments, a passivation layer 70 is further included, and the passivation layer 70 is located on the surface of the AlGaN barrier layer 60 away from the substrate 10.

[0052] Refer again to Figure 1 , in some embodiments, a cathode metal electrode 110, an anode metal electrode 90, an upper anode metal field plate 100, and a side anode metal field plate 80 are further included;

[0053] The cathode metal electrode 110 is located on the surface of the AlGaN barrier layer 60 away from the substrate 10;

[0054] The upper anode metal field plate 100 is located on the surface of the passivation layer 70 away from the substrate 10 and is spaced apart from the cathode metal electrode 110;

[0055] The side anode metal field plate 80 is located at the edge of the upper anode metal field plate 100 and penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60. The side anode metal field plate 80 is in contact with the GaN channel layer 50;

[0056] The anode metal electrode 90 penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60. The anode metal electrode 90 is in contact with the GaN channel layer 50.

[0057] In some embodiments, the cathode metal electrode 110 is located on the surface of the AlGaN barrier layer 60 away from the substrate 10 and is in contact with the passivation layer 70.

[0058] In some embodiments, the surfaces of the anode metal electrode 90, the upper anode metal field plate 100, and the side anode metal field plate 80 away from the substrate 10 are flush.

[0059] In some embodiments, the surface of the cathode metal electrode 110 away from the substrate 10 is higher than the surface of the anode metal electrode 90 away from the substrate 10.

[0060] In some embodiments, the side anode metal field plate 80 penetrates through a part of the GaN channel layer 50.

[0061] In some embodiments, the anode metal electrode 90 penetrates through a part of the GaN channel layer 50.

[0062] In some embodiments, the thickness of the passivation layer 70 is 40 nm to 80 nm. Optionally, the thickness of the passivation layer 70 is 40 nm, 42 nm, 44 nm, 46 nm, 48 nm, 50 nm, 52 nm, 54 nm, 56 nm, 57 nm, 58 nm, 60 nm, 62 nm, 67 nm, 66 nm, 68 nm, 70 nm, 72 nm, 74 nm, 76 nm, 78 nm, or 80 nm.

[0063] In some embodiments, the width of the cathode metal electrode 110 is 3 μm to 7 μm. Optionally, the width of the cathode metal electrode 110 is 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, or 7 μm.

[0064] In some embodiments, the width of the anode metal electrode 90 is 3 μm to 7 μm. Optionally, the width of the anode metal electrode 90 is 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm, 6 μm, 6.5 μm, or 7 μm.

[0065] In some embodiments, the distance between the cathode metal electrode 110 and the anode metal electrode 90 is 15 μm to 25 μm. Optionally, the distance between the cathode metal electrode 110 and the anode metal electrode 90 is 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, or 25 μm.

[0066] In some embodiments, the thickness of the upper anode metal field plate 100 is 30 nm to 50 nm. Optionally, the thickness of the upper anode metal field plate 100 is 30 nm, 31 nm, 32 nm, 33 nm, 34 nm, 35 nm, 36 nm, 37 nm, 38 nm, 39 nm, 40 nm, 41 nm, 42 nm, 43 nm, 44 nm, 45 nm, 46 nm, 47 nm, 48 nm, 49 nm, or 50 nm.

[0067] In some embodiments, the thickness of the side anode metal field plate 80 is 200 nm to 400 nm. Optionally, the thickness of the side anode metal field plate 80 is 200 nm, 210 nm, 220 nm, 230 nm, 240 nm, 250 nm, 260 nm, 270 nm, 280 nm, 290 nm, 300 nm, 310 nm, 320 nm, 330 nm, 340 nm, 350 nm, 360 nm, 370 nm, 380 nm, 390 nm, or 400 nm.

[0068] In some embodiments, the width of the side anode metal field plate 80 is 50 nm to 150 nm. Optionally, the width of the side anode metal field plate 80 is 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, 110 nm, 120 nm, 130 nm, 140 nm, or 150 nm.

[0069] In some embodiments, the material of the passivation layer 70 includes Si3N4.

[0070] In one of the embodiments, the passivation layer 70 is a Si3N4 passivation layer 70.

[0071] In some embodiments, the material of the cathode metal electrode 110 includes Ti, Al, Ni, and Au.

[0072] In one of the embodiments, the cathode metal electrode 110 is a Ti-Al-Ni-Au alloy electrode.

[0073] In some embodiments, the material of the anode metal electrode 90 includes Ni and Au.

[0074] In one of the embodiments, the anode metal electrode 90 is a Ni-Au alloy electrode.

[0075] In some embodiments, the material of the upper anode metal field plate 100 includes Ni and Au.

[0076] In one of the embodiments, the upper anode metal field plate 100 is a Ni-Au alloy field plate.

[0077] In some embodiments, the material of the side anode metal field plate 80 includes Ni and Au.

[0078] In one of the embodiments, the side anode metal field plate 80 is a Ni-Au alloy field plate.

[0079] In some embodiments, the substrate 10 includes at least one of Si, SiC, and sapphire.

[0080] Another embodiment of the present application provides a method for manufacturing a Schottky barrier diode, including:

[0081] Providing a substrate 10;

[0082] Successively preparing a stacked AlN nucleation layer 20, a GaN buffer layer 30, an InGaN back barrier layer 40, a GaN channel layer 50, and an AlGaN barrier layer 60 on the substrate 10; wherein, the content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10.

[0083] In some embodiments, it further includes: respectively preparing a passivation layer 70 and a cathode metal electrode 110 on the surface of the AlGaN barrier layer 60, and the passivation layer 70 and the cathode metal electrode 110 are in contact;

[0084] Respectively preparing an anode metal electrode 90, an upper anode metal field plate 100, and a side anode metal field plate 80 on the surface of the passivation layer 70; the upper anode metal field plate 100 is located on the surface of the passivation layer 70 away from the substrate 10 and is spaced apart from the cathode metal electrode 110; the side anode metal field plate 80 is located at the edge of the upper anode metal field plate 100 and penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60, and the side anode metal field plate 80 is in contact with the GaN channel layer 50; the anode metal electrode 90 penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60, and the anode metal electrode 90 is in contact with the GaN channel layer 50.

[0085] In some embodiments, the AlN nucleation layer 20, the GaN buffer layer 30, the InGaN back barrier layer 40, the GaN channel layer 50, and the AlGaN barrier layer 60 are prepared by metal organic chemical vapor deposition (MOCVD).

[0086] In some embodiments, the cathode metal electrode 110 is prepared by Ti-Al-Ni-Au alloy evaporation.

[0087] In some embodiments, the passivation layer 70 is prepared by low-pressure chemical vapor deposition (LPCVD).

[0088] In some embodiments, the anode metal electrode 90 is prepared by Ni-Au alloy evaporation coating.

[0089] In some embodiments, the upper anode metal field plate 100 is prepared by Ni-Au alloy evaporation coating.

[0090] In some embodiments, the side anode metal field plate 80 is prepared by Ni-Au alloy evaporation coating.

[0091] In some embodiments, the preparation method of the Schottky barrier diode comprises the following steps:

[0092] S100: Provide a substrate 10;

[0093] S200: Epitaxially grow stacked AlN nucleation layer 20, GaN buffer layer 30, InGaN back barrier layer 40, GaN channel layer 50 and AlGaN barrier layer 60 on the substrate 10 in sequence by metalorganic chemical vapor deposition (MOCVD); wherein, the content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10;

[0094] S300: Perform photolithography on the surface of the AlGaN barrier layer 60 to define the preparation region of the cathode metal electrode 110, then perform Ti-Al-Ni-Au alloy evaporation coating, and then perform photoresist stripping and annealing to form the cathode metal electrode 110;

[0095] S400: Perform photolithography on the surface of the AlGaN barrier layer 60 to define the preparation region of the passivation layer 70, and then deposit the Si3N4 passivation layer 70 by low-pressure chemical vapor deposition;

[0096] S500: Perform photolithography and etching on the surface of the passivation layer 70 to obtain the anode electrode preparation region and the side anode metal field plate 80 preparation region respectively, then perform Ni-Au alloy evaporation coating, and then perform photoresist stripping to obtain the anode metal electrode 90 and the side anode metal field plate 80. The side anode metal field plate 80 is located at the edge of the passivation layer 70 and penetrates through the passivation layer 70 and the AlGaN barrier layer 60, and the side anode metal field plate 80 contacts the GaN channel layer 50; the anode metal electrode 90 penetrates through the passivation layer 70 and the AlGaN barrier layer 60, and the anode metal electrode 90 contacts the GaN channel layer 50;

[0097] S600: Perform photolithography on the surface of the passivation layer 70 to obtain the upper anode field plate preparation area, then perform Ni-Au alloy evaporation, and then perform photoresist stripping to obtain the upper anode metal field plate 100. The upper anode metal field plate 100 is in contact with the side anode metal field plate 80 and the anode metal electrode 90.

[0098] In some embodiments, the manufacturing method of the Schottky barrier diode comprises the following steps:

[0099] S100: Provide a substrate 10;

[0100] S200: Epitaxially grow, in sequence on the substrate 10, a stacked AlN nucleation layer 20, a GaN buffer layer 30, an InGaN back barrier layer 40, a GaN channel layer 50, and an AlGaN barrier layer 60 by metal-organic chemical vapor deposition (MOCVD); wherein, the content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10;

[0101] S300: Perform photolithography on the surface of the AlGaN barrier layer 60 to define the cathode metal electrode 110 preparation area, then perform Ti-Al-Ni-Au alloy evaporation, and then perform photoresist stripping and annealing to form the cathode metal electrode 110;

[0102] S400: Perform photolithography on the surface of the AlGaN barrier layer 60 to define the passivation layer 70 preparation area, and then deposit the Si3N4 passivation layer 70 by low-pressure chemical vapor deposition;

[0103] S500: Perform photolithography and etching on the surface of the passivation layer 70 to obtain the anode electrode preparation area and the side anode metal field plate 80 preparation area respectively, then perform Ni-Au alloy evaporation, and then perform photoresist stripping to obtain the anode metal electrode 90 and the side anode metal field plate 80. The side anode metal field plate 80 is located at the edge of the passivation layer 70 and penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The side anode metal field plate 80 is in contact with the GaN channel layer 50; the anode metal electrode 90 penetrates through the passivation layer 70 and the AlGaN barrier layer 60, and the anode metal electrode 90 is in contact with the GaN channel layer 50;

[0104] S600: Perform photolithography on the surface of the passivation layer 70 to obtain the upper anode field plate preparation area, then perform Ni-Au alloy evaporation, and then perform photoresist stripping to obtain the upper anode metal field plate 100. The upper anode metal field plate 100 is in contact with the side anode metal field plate 80 and the anode metal electrode 90.

[0105] Another embodiment of the present application provides an electronic product, including the Schottky barrier diode in any of the above or the Schottky barrier diode prepared by the manufacturing method of the Schottky barrier diode in any of the above.

[0106] The following are specific embodiments

[0107] Example 1

[0108] Refer to Figure 1 In Example 1, the structure of the Schottky barrier diode is as follows: an Si substrate 10, an AlN nucleation layer 20, a GaN buffer layer 30, an InGaN back barrier layer 40, a GaN channel layer 50, and an AlGaN barrier layer 60 are stacked in sequence from bottom to top; the content of In in the InGaN back barrier layer 40 gradually increases from bottom to top; it also includes an Si3N4 passivation layer 70, and the Si3N4 passivation layer 70 is located on the surface of the AlGaN barrier layer 60 away from the substrate 10; it also includes a cathode metal electrode 110, an anode metal electrode 90, an upper anode metal field plate 100, and a side anode metal field plate 80; the cathode metal electrode 110 is located on the surface of the AlGaN barrier layer 60 away from the substrate 10 and is in contact with the passivation layer 70; the upper anode metal field plate 100 is located on the surface of the passivation layer 70 away from the substrate 10 and is spaced apart from the cathode metal electrode 110; the side anode metal field plate 80 is located at the edge of the upper anode metal field plate 100 and penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60, and the side anode metal field plate 80 partially penetrates the GaN channel layer 50; the anode metal electrode 90 penetrates through the upper anode metal field plate 100, the passivation layer 70, and the AlGaN barrier layer 60, and the anode metal electrode 90 partially penetrates the GaN channel layer 50.

[0109] Preparation method of the Schottky barrier diode:

[0110] (1) Provide an Si substrate 10;

[0111] (2) On the Si substrate 10, an AlN nucleation layer 20 with a thickness of 1 nm, a GaN buffer layer 30 with a thickness of 300 nm, an InGaN back barrier layer 40 with a thickness of 20 nm, a GaN channel layer 50 with a thickness of 200 nm, and an AlGaN barrier layer 60 with a thickness of 20 nm are sequentially epitaxially grown by metal organic chemical vapor deposition (MOCVD). The content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10. The specific change in the components of the InGaN back barrier layer 40 is In 0.01 Ga 0.99 N~In 0.08 Ga 0.92 N, and the component of the AlGaN barrier layer 60 is Al 0.2 Ga 0.8 N;

[0112] (3) Lithographically define the preparation area of the cathode metal electrode 110 on the surface of the AlGaN barrier layer 60, and then deposit a Ti-Al-Ni-Au alloy by electron beam evaporation with an electron beam energy of 3 kV and a vacuum degree P ≤ 10 -3 Pa. Then, strip the photoresist with acetone and anneal it in an N2 atmosphere to form the cathode metal electrode 110, and the width of the cathode metal electrode 110 is 5 μm;

[0113] (4) Lithographically define the preparation area of the passivation layer 70 on the surface of the AlGaN barrier layer 60, and then deposit a 60-nm-thick Si3N4 passivation layer 70 by low-pressure chemical vapor deposition. The passivation layer 70 is in contact with the cathode metal electrode 110;

[0114] (5) Perform lithography and CF4 etching on the surface of the passivation layer 70 to obtain the preparation areas of the anode metal electrode 90 and the side anode metal field plate 80 respectively. Then, deposit a Ni-Au alloy by electron beam evaporation with an electron beam energy of 3 kV and a vacuum degree P ≤ 10 -3 Pa. Then, strip the photoresist with acetone to obtain the anode metal electrode 90 and the side anode metal field plate 80. The side anode metal field plate 80 is located at the edge of the passivation layer 70 and penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The side anode metal field plate 80 partially penetrates the GaN channel layer 50. The anode metal electrode 90 penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The anode metal electrode 90 partially penetrates the GaN channel layer 50. The width of the anode metal electrode 90 is 5 μm. The distance between the anode metal electrode 90 and the cathode metal electrode 110 is 20 μm. The thickness of the side anode metal field plate 80 is 300 nm, and the width of the side anode metal field plate 80 is 100 nm;

[0115] (6) Perform lithography on the surface of the passivation layer 70 to obtain the preparation area of the upper anode metal field plate 100. Then, deposit a Ni-Au alloy by electron beam evaporation with an electron beam energy of 3 kV and a vacuum degree P ≤ 10 -3 Pa. Then, strip the photoresist with acetone to obtain the upper anode metal field plate 100. The upper anode metal field plate 100 is in contact with the side anode metal field plate 80 and the anode metal electrode 90, and the thickness of the upper anode metal field plate 100 is 40 nm.

[0116] Example 2

[0117] The structure of the Schottky barrier diode obtained in Example 2 is the same as that in Example 1.

[0118] Preparation method of the Schottky barrier diode:

[0119] (1) Provide a Si substrate 10;

[0120] (2) On the Si substrate 10, a stacked AlN nucleation layer 20 with a thickness of 1 nm, a GaN buffer layer 30 with a thickness of 300 nm, an InGaN back barrier layer 40 with a thickness of 20 nm, a GaN channel layer 50 with a thickness of 200 nm, and an AlGaN barrier layer 60 with a thickness of 20 nm are successively epitaxially grown by metalorganic chemical vapor deposition (MOCVD). The content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10. The specific change in the composition of the InGaN back barrier layer 40 is In 0.08 Ga 0.92 N~In 0.15 Ga 0.85 N, and the composition of the AlGaN barrier layer 60 is Al 0.2 Ga 0.8 N;

[0121] (3) On the surface of the AlGaN barrier layer 60, the preparation area of the cathode metal electrode 110 is defined by photolithography, and then Ti - Al - Ni - Au alloy evaporation is carried out. The evaporation is carried out by electron beam evaporation, the electron beam energy is 3 kV, and the vacuum degree P≤10 -3 Pa. Then, photoresist stripping is carried out with acetone and annealing is carried out in an N2 atmosphere to form the cathode metal electrode 110. The width of the cathode metal electrode 110 is 5 μm;

[0122] (4) On the surface of the AlGaN barrier layer 60, the preparation area of the passivation layer 70 is defined by photolithography, and then a Si3N4 passivation layer 70 with a thickness of 60 nm is deposited by low - pressure chemical vapor deposition. The passivation layer 70 is in contact with the cathode metal electrode 110;

[0123] (5) On the surface of the passivation layer 70, photolithography and CF4 etching source etching are carried out to obtain the preparation areas of the anode metal electrode 90 and the side anode metal field plate 80 respectively. Then, Ni - Au alloy evaporation is carried out. The evaporation is carried out by electron beam evaporation, the electron beam energy is 3 kV, and the vacuum degree P≤10 -3 Pa. Then, photoresist stripping is carried out with acetone to obtain the anode metal electrode 90 and the side anode metal field plate 80. The side anode metal field plate 80 is located at the edge of the passivation layer 70 and penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The side anode metal field plate 80 partially penetrates the GaN channel layer 50. The anode metal electrode 90 penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The anode metal electrode 90 partially penetrates the GaN channel layer 50. The width of the anode metal electrode 90 is 5 μm. The distance between the anode metal electrode 90 and the cathode metal electrode 110 is 20 μm. The thickness of the side anode metal field plate 80 is 300 nm, and the width of the side anode metal field plate 80 is 100 nm;

[0124] (6) Lithography is performed on the surface of the passivation layer 70 to obtain the preparation area of the upper anode metal field plate 100, and then Ni-Au alloy evaporation is carried out. The evaporation is performed by electron beam evaporation with an electron beam energy of 3 kV and a vacuum degree P ≤ 10 -3 Pa. Then, acetone is used for photoresist stripping to obtain the upper anode metal field plate 100. The upper anode metal field plate 100 is in contact with the side anode metal field plate 80 and the anode metal electrode 90, and the thickness of the upper anode metal field plate 100 is 40 nm.

[0125] Example 3

[0126] The structure of the Schottky barrier diode obtained in Example 3 is the same as that in Example 1.

[0127] Preparation method of Schottky barrier diode:

[0128] (1) Provide a Si substrate 10;

[0129] (2) On the Si substrate 10, a stacked AlN nucleation layer 20 with a thickness of 1 nm, a GaN buffer layer 30 with a thickness of 300 nm, an InGaN back barrier layer 40 with a thickness of 20 nm, a GaN channel layer 50 with a thickness of 200 nm, and an AlGaN barrier layer 60 with a thickness of 20 nm are sequentially epitaxially grown by metalorganic chemical vapor deposition (MOCVD). The content of In in the InGaN back barrier layer 40 gradually increases in the direction away from the substrate 10. The specific change in the composition of the InGaN back barrier layer 40 is In 0.15 Ga 0.85 N ~ In 0.22 Ga 0.78 N, and the composition of the AlGaN barrier layer 60 is Al 0.2 Ga 0.8 N;

[0130] (3) On the surface of the AlGaN barrier layer 60, the preparation area of the cathode metal electrode 110 is defined by lithography, and then Ti-Al-Ni-Au alloy evaporation is carried out. The evaporation is performed by electron beam evaporation with an electron beam energy of 3 kV and a vacuum degree P ≤ 10 -3 Pa. Then, photoresist stripping is carried out using acetone and annealing is carried out in an N2 atmosphere to form the cathode metal electrode 110, and the width of the cathode metal electrode 110 is 5 μm;

[0131] (4) On the surface of the AlGaN barrier layer 60, the preparation area of the passivation layer 70 is defined by lithography, and then a 60-nm-thick Si3N4 passivation layer 70 is deposited by low-pressure chemical vapor deposition. The passivation layer 70 is in contact with the cathode metal electrode 110;

[0132] (5) Lithography and CF4 etch source etching are performed on the surface of the passivation layer 70 to obtain the preparation areas for the anode metal electrode 90 and the side anode metal field plate 80 respectively. Then, Ni-Au alloy evaporation is carried out. The electron beam evaporation is used, the electron beam energy is 3 kV, and the vacuum degree P ≤ 10 -3 Pa. Then, acetone is used for photoresist stripping to obtain the anode metal electrode 90 and the side anode metal field plate 80. The side anode metal field plate 80 is located at the edge of the passivation layer 70 and penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The side anode metal field plate 80 partially penetrates the GaN channel layer 50. The anode metal electrode 90 penetrates through the passivation layer 70 and the AlGaN barrier layer 60. The anode metal electrode 90 partially penetrates the GaN channel layer 50. The width of the anode metal electrode 90 is 5 μm, the distance between the anode metal electrode 90 and the cathode metal electrode 110 is 20 μm, the thickness of the side anode metal field plate 80 is 300 nm, and the width of the side anode metal field plate 80 is 100 nm;

[0133] (6) Lithography is performed on the surface of the passivation layer 70 to obtain the preparation area for the upper anode metal field plate 100. Then, Ni-Au alloy evaporation is carried out. The electron beam evaporation is used, the electron beam energy is 3 kV, and the vacuum degree P ≤ 10 -3 Pa. Then, acetone is used for photoresist stripping to obtain the upper anode metal field plate 100. The upper anode metal field plate 100 is in contact with the side anode metal field plate 80 and the anode metal electrode 90. The thickness of the upper anode metal field plate 100 is 40 nm.

[0134] The Schottky barrier diodes prepared in Examples 1 to 3 all have good stability.

[0135] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope described in this specification.

[0136] The above-described embodiments only represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims, and the specification and the drawings can be used to explain the content of the claims.

Claims

1. A Schottky barrier diode, characterized in that, Comprising: A substrate, an AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer, and an AlGaN barrier layer sequentially stacked on the substrate; the content of In in the InGaN back barrier layer gradually increases in the direction away from the substrate; A passivation layer located on the surface of the AlGaN barrier layer away from the substrate; A cathode metal electrode, an anode metal electrode, an upper anode metal field plate, and a side anode metal field plate; The cathode metal electrode is located on the surface of the AlGaN barrier layer away from the substrate; The upper anode metal field plate is located on the surface of the passivation layer away from the substrate and is spaced apart from the cathode metal electrode; The side anode metal field plate is located at the edge of the upper anode metal field plate and penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the side anode metal field plate is in contact with the GaN channel layer; The anode metal electrode penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the anode metal electrode is in contact with the GaN channel layer.

2. The Schottky barrier diode according to claim 1, characterized in that, The thickness of the AlN nucleation layer is 0.5 nm to 1.5 nm; And / or, the thickness of the GaN buffer layer is 200 nm to 400 nm; And / or, the thickness of the InGaN back barrier layer is 10 nm to 30 nm; And / or, the thickness of the GaN channel layer is 100 nm to 300 nm; And / or, the thickness of the AlGaN barrier layer is 10 nm to 30 nm.

3. The Schottky barrier diode according to claim 1, characterized in that, In the InGaN back barrier layer, calculated by the percentage of the amount of substance of In in the total amount of In and Ga, the amount of substance of In is 1% to 22%.

4. The Schottky barrier diode according to claim 1, characterized in that, The thickness of the passivation layer is 40 nm to 80 nm.

5. The Schottky barrier diode according to claim 1, characterized in that, The width of the cathode metal electrode is 3 μm to 7 μm; And / or, the width of the anode metal electrode is 3 μm to 7 μm; And / or, the distance between the cathode metal electrode and the anode metal electrode is 15 μm to 25 μm.

6. The Schottky barrier diode according to claim 1, characterized in that, The thickness of the upper anode metal field plate is 30 nm to 50 nm; And / or, the thickness of the side anode metal field plate is 200 nm to 400 nm; And / or, the width of the side anode metal field plate is 50 nm to 150 nm.

7. The Schottky barrier diode according to claim 1, characterized in that, The material of the passivation layer includes Si3N 4。 8. The Schottky barrier diode according to claim 1, characterized in that, The material of the cathode metal electrode includes Ti, Al, Ni, and Au; And / or, the material of the anode metal electrode includes Ni and Au; And / or, the material of the upper anode metal field plate includes Ni and Au; And / or, the material of the side anode metal field plate includes Ni and Au.

9. A method for manufacturing a Schottky barrier diode, characterized in that, Comprising: Providing a substrate; Sequentially preparing and stacking an AlN nucleation layer, a GaN buffer layer, an InGaN back barrier layer, a GaN channel layer, and an AlGaN barrier layer on the substrate; wherein, the content of In in the InGaN back barrier layer gradually increases in the direction away from the substrate; Preparing a passivation layer and a cathode metal electrode on the surface of the AlGaN barrier layer respectively; An anode metal electrode, an upper anode metal field plate, and a side anode metal field plate are respectively prepared on the surface of the passivation layer; the upper anode metal field plate is located on the surface of the passivation layer away from the substrate and is spaced apart from the cathode metal electrode; the side anode metal field plate is located at the edge of the upper anode metal field plate and penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the side anode metal field plate is in contact with the GaN channel layer; the anode metal electrode penetrates through the upper anode metal field plate, the passivation layer, and the AlGaN barrier layer, and the anode metal electrode is in contact with the GaN channel layer.

10. An electronic product, characterized in that, A Schottky barrier diode comprising the Schottky barrier diode according to any one of claims 1 to 8 or the Schottky barrier diode prepared by the method for preparing the Schottky barrier diode according to claim 9.

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