CN114335169B - Gallium nitride Schottky barrier diode and manufacturing method thereof - Google Patents
Gallium nitride Schottky barrier diode and manufacturing method thereof Download PDFInfo
- Publication number
- CN114335169B CN114335169B CN202111413596.4A CN202111413596A CN114335169B CN 114335169 B CN114335169 B CN 114335169B CN 202111413596 A CN202111413596 A CN 202111413596A CN 114335169 B CN114335169 B CN 114335169B
- Authority
- CN
- China
- Prior art keywords
- layer
- schottky barrier
- gan epitaxial
- epitaxial layer
- nickel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 229910002601 GaN Inorganic materials 0.000 title claims abstract description 112
- 230000004888 barrier function Effects 0.000 title claims abstract description 81
- JMASRVWKEDWRBT-UHFFFAOYSA-N Gallium nitride Chemical compound [Ga]#N JMASRVWKEDWRBT-UHFFFAOYSA-N 0.000 title claims abstract description 38
- 238000004519 manufacturing process Methods 0.000 title claims description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 85
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 60
- -1 nickel nitride Chemical class 0.000 claims abstract description 53
- 239000010931 gold Substances 0.000 claims abstract description 29
- 239000000758 substrate Substances 0.000 claims abstract description 26
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052737 gold Inorganic materials 0.000 claims abstract description 24
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 20
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Substances N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 20
- 238000002347 injection Methods 0.000 claims abstract description 13
- 239000007924 injection Substances 0.000 claims abstract description 13
- 238000001704 evaporation Methods 0.000 claims abstract description 10
- 238000000034 method Methods 0.000 claims description 39
- 238000005566 electron beam evaporation Methods 0.000 claims description 17
- 239000010936 titanium Substances 0.000 claims description 16
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 14
- 229910052594 sapphire Inorganic materials 0.000 claims description 14
- 239000010980 sapphire Substances 0.000 claims description 14
- 229910052719 titanium Inorganic materials 0.000 claims description 14
- 229910052782 aluminium Inorganic materials 0.000 claims description 11
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 11
- 238000000151 deposition Methods 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 6
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 4
- 238000010894 electron beam technology Methods 0.000 abstract description 7
- 229910052751 metal Inorganic materials 0.000 description 18
- 239000002184 metal Substances 0.000 description 18
- 239000000463 material Substances 0.000 description 17
- 229920002120 photoresistant polymer Polymers 0.000 description 12
- XCZXGTMEAKBVPV-UHFFFAOYSA-N trimethylgallium Chemical compound C[Ga](C)C XCZXGTMEAKBVPV-UHFFFAOYSA-N 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000004065 semiconductor Substances 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 3
- 229910052733 gallium Inorganic materials 0.000 description 3
- 239000002994 raw material Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Natural products N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 2
- XKMRRTOUMJRJIA-UHFFFAOYSA-N ammonia nh3 Chemical compound N.N XKMRRTOUMJRJIA-UHFFFAOYSA-N 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910052732 germanium Inorganic materials 0.000 description 2
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 2
- 238000001259 photo etching Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000000927 vapour-phase epitaxy Methods 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000001312 dry etching Methods 0.000 description 1
- 230000005684 electric field Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000000407 epitaxy Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Landscapes
- Electrodes Of Semiconductors (AREA)
Abstract
The invention discloses a gallium nitride Schottky barrier diode which is of a multilayer structure and sequentially comprises a substrate (1), a buffer layer (2), an i-GaN epitaxial layer (3 a) and an n-GaN epitaxial layer (3 b) from bottom to top, wherein an ohmic electrode (4) which is in ohmic contact with the n-GaN epitaxial layer (3 b) and a Schottky barrier electrode (5) which is in Schottky barrier contact with the n-GaN epitaxial layer are arranged on the n-GaN epitaxial layer (3 b), and the Schottky barrier electrode (5) sequentially comprises a nickel nitride layer and a gold layer from bottom to top, and the nickel nitride layer and the n-GaN epitaxial layer (3 b) form the Schottky barrier contact. The nickel nitride layer is prepared by adopting a nitrogen ion auxiliary injection type electron beam nickel evaporation method. The invention solves the technical problems of larger reverse leakage current and poor stability of the traditional Schottky barrier diode.
Description
Technical Field
The invention relates to the technical field of third-generation semiconductor materials and devices, in particular to a structure of a gallium nitride Schottky barrier diode and a manufacturing method thereof.
Background
Schottky Barrier Diode (SBD) is a key device of rectifier circuit, and is widely used in fields such as ac-dc conversion, electric automobile power charging, and energy collection. Recently, with the development and popularization of microwave communication, devices are required to be adapted to the operation characteristics at high frequencies, have high stability at high frequencies and high conversion efficiency. Conventional GaAs-based and Si-based commercial schottky barrier diodes have difficulty meeting these new requirements. Gallium nitride (GaN) based materials have the characteristics of high electron mobility, high electron saturation velocity, wide forbidden bandwidth, high breakdown field and the like, so that the semiconductor GaN materials are used for manufacturing the SBD device, and the SBD device is widely focused particularly in the field of microwave wireless power transmission systems. The manufacturing stability is good, the reverse leakage current is small, and the diode with high withstand voltage is an urgent requirement of the market.
However, the schottky barrier diode manufactured by the conventional technology has the technical problems of large reverse leakage current and insufficient stability.
Disclosure of Invention
The present invention aims to solve the above-mentioned problems.
The first aspect of the invention provides a gallium nitride Schottky barrier diode which is of a multilayer structure and sequentially comprises a substrate (1), a buffer layer (2), an i-GaN epitaxial layer (3 a) and an n-GaN epitaxial layer (3 b) from bottom to top, wherein an ohmic electrode (4) which is in ohmic contact with the n-GaN epitaxial layer (3 b) and a Schottky barrier electrode (5) which is in Schottky barrier contact with the n-GaN epitaxial layer are arranged on the n-GaN epitaxial layer (3 b), the Schottky barrier electrode (5) sequentially comprises a nickel nitride layer (NiN layer) and a gold layer (Au layer) from bottom to top, and the nickel nitride layer and the n-GaN epitaxial layer (3 b) form Schottky contact.
The substrate used in the present invention is appropriately selected according to the material on which the epitaxial layer is to be formed, and the preparation method, the ease of starting, and the price. In the invention, sapphire is preferably selected as a substrate in consideration of factors such as lattice and thermal expansion coefficient matching with an epitaxial layer, cost and the like. Other substrates may be used, for example, siC, silicon, germanium, oxides (ZnO, liGaO2, liAlO2, mgO, etc.), group iii-v compounds of the periodic table (GaN, gaAs, alN, alGaN, al InN, etc.), borides (ZrB 2, etc.), and the like.
In order to obtain a good GaN epitaxial material, it is necessary to consider the matching of lattice and thermal expansion coefficients between the substrate and the material to be epitaxial, and a buffer layer is generally used as a transition layer between the substrate and the epitaxial layer to be grown. In selecting the material of the buffer layer, both the lattice and thermal expansion coefficient matching between the substrate and the material to be epitaxially used and the composition, structure and formation of layers of the device layer epitaxially used on the buffer layer are considered. The invention adopts the traditional low-temperature GaN layer as the buffer layer. In addition, III-V compound materials such as AlN can be used. The thickness of the buffer layer is between 1 and 30nm, more preferably between 1 and 10nm, and most preferably between 3 and 10nm. The dislocation density of the buffer layer should be as small as possible, which would affect the quality of the subsequent film formation, and preferably the dislocation density should be controlled below 1×10 11/cm2. The buffer layer may be formed by a well-known film forming method such as MOCVD or MBE.
Preferably, the thickness of the nickel nitride layer forming the Schottky barrier electrode (5) is 10-30nm, and the thickness of the gold layer is 50-200nm.
Preferably, the ohmic electrode (4) includes, in order from bottom to top, a titanium layer, an aluminum layer, a nickel layer, and a gold layer (hereinafter abbreviated as Ti/Al/Ni/Au layer), wherein the titanium layer makes ohmic contact with the n-GaN epitaxial layer (3 b).
Preferably, the thickness of the titanium layer is 10-30nm, the thickness of the aluminum layer is 80-150nm, the thickness of the nickel layer is 30-60nm, and the thickness of the gold layer is 50-200nm.
A second aspect of the present invention relates to a method for manufacturing a gallium nitride schottky barrier diode according to the first aspect, comprising the steps of:
1) Sequentially growing a buffer layer (2), an i-GaN epitaxial layer (3 a) and an n-GaN epitaxial layer (3 b) on a substrate (1); then
2) An ohmic electrode (4) forming ohmic contact with the n-GaN epitaxial layer (3 b) is locally deposited; and depositing a nickel nitride layer on the other part of the n-GaN epitaxial layer (3 b) by using a nitrogen ion auxiliary injection type electron beam evaporation method, and then depositing a gold layer on the nickel nitride layer by using an electron beam evaporation method, wherein the nickel nitride layer and the gold layer form the Schottky barrier electrode (5).
Preferably, the ohmic electrode (4) is formed by depositing a titanium layer, an aluminum layer, a nickel layer and a gold layer on a part of the n-GaN epitaxial layer (3 b) sequentially by an electron beam evaporation process, and performing a heat treatment in a nitrogen atmosphere at 800-850 ℃ for 20-40 seconds.
Preferably, the thickness of the substrate (1) is 430 mu m, and the surface orientation of the substrate is C-plane and is inclined to m-plane by 0.15 degrees.
Preferably, the buffer layer (2) is a GaN material buffer layer grown on a sapphire substrate by a metal organic chemical vapor epitaxy (MOCVD) method through a low temperature GaN layer as a buffer layer.
The i-GaN epitaxial layer (3 a) and the n-GaN epitaxial layer (3 b) are also deposited by adopting an organic metal chemical vapor phase epitaxy method. Wherein the i-GaN epitaxial layer is also called an undoped gallium nitride layer, and the n-GaN (also called an n-type doped gallium nitride layer) is formed by doping a tetravalent element (e.g., silicon or germanium) into gallium nitride, and its carriers are electrons. The thickness of the i-GaN layer is 0-3 μm, and the thickness of the n-GaN epitaxial layer is 1-3 μm.
And a titanium/aluminum/nickel/gold (Ti/Al/Ni/Au) layer with the thickness of (10-30/80-150/30-60/50-200 nm) is sequentially deposited on a specific local area of the n-GaN epitaxial layer from bottom to top, and the titanium layer is in ohmic contact with the n-GaN epitaxial layer to form an ohmic electrode (4) of the Schottky barrier diode.
And a nickel nitride/gold (NiN/Au) film with the thickness of (10-30/50-200 nm) is deposited on another specific local area of the n-GaN epitaxial layer sequentially from bottom to top. The nickel nitride film layer and the n-GaN epitaxial layer form Schottky barrier contact to form a Schottky barrier electrode (5) of the Schottky barrier diode.
More specifically, the method for manufacturing the gallium nitride Schottky barrier diode provided by the invention comprises the following steps:
Z1: preparing a sapphire substrate (1) with a thickness of 430 mu m, wherein the surface orientation of the epitaxial growth surface of the sapphire substrate is C surface and is inclined to m surface by 0.15 degrees;
Z2: the sapphire substrate is arranged in a reaction furnace of metal organic chemical vapor deposition equipment, the epitaxial surface of the sapphire is further purified in a high-temperature (1000 ℃) reducing atmosphere, a Metal Organic Chemical Vapor Deposition (MOCVD) method is adopted on the purified surface of the sapphire substrate, and a GaN buffer layer (2) is grown by taking trimethylgallium (TMGa) and NH3 as raw materials at a low temperature of 550 ℃ and has a thickness of 10-30 nm;
Z3: after the GaN buffer layer grows, the temperature is gradually increased to 1050 ℃, and the epitaxial layers of i-GaN and n-GaN are sequentially grown by taking TMGa and NH3 as raw materials. The n-GaN epitaxial layer uses SiH 4 as a doping source, and the doping concentration is in the range of 8 multiplied by 10 15cm-3—1×1017cm-3;
z4: sequentially evaporating titanium/aluminum/nickel/Jin Duoceng metal on the surface of the n-GaN epitaxial layer by adopting an electron beam evaporation method on the clean surface of the n-GaN epitaxial layer, wherein the thickness of the titanium/aluminum/nickel/Jin Duoceng metal is respectively (10-30/80-150/30-60/50-200 nm), then stripping the metal outside an ohmic electrode area by adopting a photoetching method, forming an ohmic electrode in the multi-layer metal area which is not stripped, and carrying out heat treatment in a nitrogen atmosphere, wherein the heat treatment temperature is 800-850 ℃, and the heat treatment time is 20-40 seconds, so as to form an ohmic electrode (4);
Z5: and depositing a nickel nitride film in a region where the Schottky barrier electrode is to be formed by adopting a nitrogen ion auxiliary injection type electron beam nickel evaporation method. When the nickel nitride film is deposited by adopting a nitrogen ion auxiliary injection type electron beam evaporation nickel method, the current density of nitrogen ions at the n-GaN epitaxial layer is 0.02 mu Acm -2, and the energy when the ions reach the surface of the n-GaN epitaxial layer is controlled between 20eV and 30eV, so that a good compact nickel nitride film layer can be obtained under the condition.
Z6: then evaporating the gold film by electron beam. After evaporating a nickel nitride/gold (NiN/Au) film, forming a Schottky barrier electrode (5) with a specific shape on a Schottky barrier electrode region on the n-GaN epitaxial layer by adopting a photoetching stripping process, wherein the nickel nitride film and the n-GaN epitaxial layer form Schottky contact, the thickness of the nickel nitride film layer is 10-30nm, and the thickness of the gold film layer is 50-200nm.
The invention has the beneficial effects that:
the invention provides a Schottky barrier diode and a manufacturing method thereof. In particular, the excellent characteristics of the Schottky barrier formed by n-GaN and high-quality nickel nitride manufactured by a nitrogen ion auxiliary injection type electron beam evaporation nickel method are utilized, and the Schottky barrier diode with small reverse current and stable performance is realized.
The Schottky barrier diode manufactured by the GaN material is characterized in that the characteristics of wide forbidden band width, high electric field breakdown strength, high electron mobility and high electron saturation speed of the GaN epitaxial layer material are fully utilized, the Schottky barrier formed by the surface of the GaN material and the nickel nitride forms the device, the device can be used in a severe high-temperature environment, meanwhile, the reverse recovery speed of the device is high, the device is suitable for being used in a high-frequency circuit, and the power conversion efficiency of a microwave system is improved. Experimental data indicate that: the high-quality nickel nitride film layer manufactured by the method of nitrogen ion auxiliary injection type electron beam evaporation nickel replaces a metal layer deposited by a traditional method to be used as a Schottky contact, has higher stability and lower reverse leakage current, and compared with a device manufactured by the traditional method, the reverse leakage current is reduced by at least two orders of magnitude. Compared with the traditional diode, the diode provided by the invention can effectively reduce the power consumption of the device and improve the efficiency of the device.
Drawings
In order to more clearly illustrate the technical scheme of the present invention and to more clearly understand the specific embodiments, the structure of the schottky barrier diode of the present invention is shown using the accompanying drawings, and the specific embodiments of the present invention and the technical description of the present invention are conveniently and orderly described using the accompanying drawings. It is apparent that the drawings in the following description are structural cross-sectional views of the schottky barrier diode of the present invention. It will be apparent to those of ordinary skill in the art that other arrangements may be made in accordance with the arrangements shown in the drawings without undue burden.
FIG. 1 is a schematic diagram of a specific GaN Schottky barrier diode according to the present invention;
fig. 2 is a schematic diagram of another embodiment of a gan schottky barrier diode according to the present invention;
The reference numerals have the following meanings:
1. A sapphire substrate; 2. a buffer layer; 3a, i-GaN epitaxial layers; 3b, an n-GaN epitaxial layer; a 4-ohmic electrode; a 5-schottky barrier electrode.
Detailed Description
Embodiments of the technical scheme of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are given for the purpose of more clearly illustrating the technical aspects of the present invention. And thus are merely examples and are not intended to limit the scope of the present invention.
It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs.
Throughout the description of this patent, for the purposes of facilitating or simplifying the description of the present invention, terms of "upper", "lower", "left", "right", and the like, indicating an azimuth or a positional relationship in the description should be understood as being based on the azimuth or the positional relationship shown in the drawings, rather than indicating or implying a specific azimuth, a specific azimuth configuration, and an operation order in which the indicated location or fitting must actually have, and thus should not be construed as limiting the present invention.
Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as either explicit or implicit with respect to their relative importance, or as explicit or implicit with respect to the number of technical features indicated. In the description of the present invention, the meaning of "plurality" means three or more unless specifically defined otherwise.
In the present application, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature "above," "over" and "on" a second feature may be a first feature directly above or obliquely above the second feature, or simply indicate that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.
Example 1
As shown in fig. 1, this embodiment discloses a gallium nitride schottky barrier diode using sapphire as a substrate, which is a multilayer structure and sequentially includes, from bottom to top, a substrate (1), a buffer layer (2), an i-GaN epitaxial layer (3 a), and an n-GaN epitaxial layer (3 b), wherein an ohmic electrode (4) forming ohmic contact with the n-GaN epitaxial layer (3 b) and a schottky barrier electrode (5) forming schottky barrier contact with the n-GaN epitaxial layer are disposed on the n-GaN epitaxial layer (3 b), the schottky barrier electrode (5) sequentially includes a nickel nitride layer and a gold layer from bottom to top, and the nickel nitride layer and the n-GaN epitaxial layer (3 b) form a schottky barrier contact.
The manufacturing method of the gallium nitride Schottky barrier diode comprises the following steps: each GaN epitaxial layer was grown on a sapphire substrate by MOCVD (metal organic chemical vapor phase epitaxy). The sapphire substrate is made of C-plane sapphire with thickness of 430 μm and inclination of 0.15 degree to m-plane, and adopts low temperature GaN layer as buffer layer, and is epitaxially coated with i-GaN layer and n-GaN epitaxial layer, and Schottky barrier diode is manufactured on the GaN epitaxial layer.
The specific manufacturing method is as follows:
The sapphire substrate with the clean surface is placed on a tray of an MOCVD reaction furnace, surface re-cleaning treatment is carried out at high temperature (more than 1000 ℃) in a reducing atmosphere, and then the temperature is reduced to 550 ℃ to carry out low-temperature growth of GaN materials, wherein the raw materials are gallium organic compounds of trimethylgallium (TMGa) and ammonia NH3. Then gradually heating to crystallize the low-temperature buffer layer material atomic sequence, adjusting the flow of organic compound (TMGa) of gallium to control the growth rate and the growth time to obtain the expected thickness, wherein the thickness of the GaN buffer layer is controlled at 10nm. After forming the buffer layer, a subsequent GaN material is then epitaxially grown.
Trimethyl gallium (TMGa) serving as a gallium source and ammonia NH3 serving as a nitrogen source are introduced into the reaction furnace, and epitaxial growth conditions are as follows: the furnace pressure was 760Torr, the temperature was 1050 ℃, and the molar ratio of V/III group element was 4600. The thickness of the i-GaN epitaxial layer is 1um, and the thickness of the n-GaN epitaxial layer is 0.5um. The n-GaN layer is a device layer with n-type carrier concentration of 8 multiplied by 10 16/cm <3 > obtained by Si doping with doped gas SiH4 as a source.
Then, an ohmic electrode and a Schottky barrier electrode are formed on the n-GaN epitaxial layer. In this embodiment, an ohmic electrode is formed first, and then a schottky barrier electrode is formed.
Wherein the ohmic electrode is formed as follows:
z1, sequentially evaporating titanium/aluminum/nickel/Jin Duoceng metal on the surface of the n-GaN epitaxial layer by adopting an electron beam evaporation method on the surface of the n-GaN epitaxial layer after the cleaning treatment, wherein the thicknesses of the titanium/aluminum/nickel/Jin Duoceng metal are respectively (10/100/30/150 nm);
Uniformly coating photoresist on the surface of the metal deposited by the electron beam evaporation method;
Z3, using a photomask with an ohmic electrode area pattern to be obtained as a mask, and carrying out exposure treatment by using light with a proper wavelength matched with the photoresist;
Z4, developing the photoresist to remove the photoresist in the non-ohmic electrode area of the diode;
And Z5, removing the metal layer from which the photoresist area is removed by a dry etching (such as plasma etching) method or a wet etching (such as acid etching) method, completely exposing the surface of the n-GaN epitaxial layer, and removing the photoresist on other areas of the surface. The remaining multilayer metal region, which was not peeled off, was formed into an ohmic electrode, and heat-treated in a nitrogen atmosphere at 820℃for 30 seconds to form an ohmic electrode.
The process of forming the schottky barrier electrode on the n-GaN epitaxial layer is as follows:
uniformly coating photoresist on the surface of a chip with an ohmic electrode;
Z2, using a photomask with a Schottky barrier electrode region pattern to be obtained as a mask, and performing exposure treatment by using a proper wavelength matched with photoresist after position calibration;
z3, developing the photoresist, removing the photoresist of the region of the diode where the Schottky contact electrode is to be formed, and completely exposing the n-GaN surface of the region where the Schottky barrier electrode is to be formed;
Z4, completely removing residual photoresist on the exposed n-GaN surface by putting the wafer in an oxygen plasma environment;
And Z5, depositing a nickel nitride film by adopting a nitrogen ion auxiliary injection type electron beam nickel evaporation method. When the nickel nitride film is deposited by adopting a nitrogen ion auxiliary injection type electron beam evaporation method, the current density of nitrogen ions at the n-GaN epitaxial layer is 0.02 mu Acm -2, the energy when the ions reach the surface of the n-GaN epitaxial layer is controlled between 20eV and 30eV, and a good compact nickel nitride film layer can be obtained under the condition, wherein the thickness of the nickel nitride film layer is 10nm;
And Z6, evaporating the gold film by adopting an electron beam, wherein the thickness of the gold film layer is 200nm. And removing the metal layer of the non-Schottky barrier electrode region by adopting a gold tearing method, and cleaning to remove residual photoresist, so that the Schottky barrier electrode with a specific shape is formed on the Schottky barrier electrode region of the n-GaN epitaxial layer.
In this embodiment, the schottky barrier electrode region is formed in a circular shape, the ohmic electrode region is formed on the outer periphery of the schottky barrier electrode, and the inner edge of the ohmic electrode is formed in a circular ring concentric with the schottky barrier electrode (see fig. 1). The positions and shapes of the ohmic electrode and the schottky barrier electrode are not limited to the above description, and there are many other options such as a region of the ohmic electrode where the left side of the chip is provided as an ohmic contact, a region of the schottky barrier electrode where the right side is provided as a schottky contact (refer to fig. 2), and the like.
In the invention, when the nickel nitride film is deposited by using a nitrogen ion auxiliary injection type electron beam evaporation method, the film of NiN, ni 2 N or Ni 3 N or a mixed film layer thereof can be obtained by adjusting the ratio of the nitrogen ion number generated by a nitrogen ion gun and the evaporation rate of the electron beam nickel and the energy of the nitrogen ions reaching the Schottky barrier electrode deposition surface.
The nickel nitride film of the electrode forms Schottky contact with the epitaxial layer, becomes the most important component of the GaN Schottky barrier diode, and completes the nonlinear rectification characteristic function of the Schottky barrier diode. In the Schottky barrier electrode, the nickel nitride film layer formed by adopting the method of nitrogen ion auxiliary injection type electron beam evaporation nickel replaces the traditional metal to be used as the Schottky contact, so that the reverse leakage current is reduced, and the stability of the Schottky barrier diode is improved.
We fabricated Schottky diodes according to the process of example 1, with the structure shown in FIG. 1, and samples were fabricated by merely changing the fabrication method of the Schottky electrode, with the other process conditions unchanged: sample (1) as a comparative example: forming a Schottky barrier diode sample by the nickel layer evaporated by the electron beam and the n-GaN semiconductor epitaxial layer; sample (2) as an example: the experimental data of the nickel nitride layer and the n-GaN semiconductor epitaxial layer which are manufactured by the method of nitrogen ion auxiliary injection type electron beam evaporation of nickel form a sample of a Schottky barrier diode, and compared with the sample of the Schottky barrier diode show that: the high-quality nickel nitride film layer manufactured by the method of nitrogen ion auxiliary injection type electron beam evaporation nickel replaces a nickel metal layer manufactured by a traditional method to be used as a Schottky barrier diode formed by a Schottky contact electrode, has higher stability and lower reverse leakage current, and the reverse leakage current is reduced by at least two orders of magnitude (when the reverse voltage is 25V). Compared with the traditional Schottky barrier diode, the Schottky barrier diode can effectively reduce the power consumption of the device and improve the efficiency of the device.
In the description of the present invention, numerous specific details are set forth. It will be apparent, however, to one skilled in the art that the embodiments of the invention may be practiced without these specific details. Well-known methods, structures and techniques have not been shown in detail in the illustrated examples, and are not intended to obscure the understanding of this description. In this specification, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the process sequences of the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by one skilled in the art without contradiction.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention, and are intended to be included within the scope of the appended claims and description.
Claims (6)
1. The gallium nitride Schottky barrier diode is of a multilayer structure and sequentially comprises a substrate (1), a buffer layer (2), an i-GaN epitaxial layer (3 a) and an n-GaN epitaxial layer (3 b) from bottom to top, wherein an ohmic electrode (4) which is in ohmic contact with the n-GaN epitaxial layer (3 b) and a Schottky barrier electrode (5) which is in Schottky barrier contact with the n-GaN epitaxial layer are arranged on the n-GaN epitaxial layer (3 b), and the gallium nitride Schottky barrier diode is characterized in that the Schottky barrier electrode (5) sequentially comprises a nickel nitride layer and a gold layer from bottom to top, and the nickel nitride layer and the n-GaN epitaxial layer (3 b) form a Schottky barrier contact;
the gallium nitride Schottky barrier diode comprises the following manufacturing steps:
1) Sequentially growing a buffer layer (2), an i-GaN epitaxial layer (3 a) and an n-GaN epitaxial layer (3 b) on a substrate (1); then, the process is carried out,
2) An ohmic electrode (4) forming ohmic contact with the n-GaN epitaxial layer (3 b) is locally deposited; and depositing a nickel nitride layer on the other part of the n-GaN epitaxial layer (3 b) by using a nitrogen ion auxiliary injection type electron beam evaporation method, and then evaporating and depositing a gold layer on the nickel nitride layer by using an electron beam evaporation method, wherein the nickel nitride layer and the gold layer form the Schottky barrier electrode (5).
2. Gallium nitride schottky barrier diode according to claim 1, characterized in that the ohmic electrode (4) comprises, in order from bottom to top, a titanium layer, an aluminum layer, a nickel layer and a gold layer, wherein the titanium layer forms an ohmic contact with the n-GaN epitaxial layer (3 b).
3. The gan schottky barrier diode of claim 1 wherein the nickel nitride layer has a thickness of 10-30nm and the gold layer has a thickness of 50-200nm.
4. The gan schottky barrier diode of claim 2 wherein the titanium layer has a thickness of 10-30nm, the aluminum layer has a thickness of 80-150nm, the nickel layer has a thickness of 30-60nm, and the gold layer has a thickness of 50-200nm.
5. Gallium nitride schottky barrier diode according to claim 1, characterized in that the substrate (1) is a sapphire substrate.
6. The method of manufacturing a gallium nitride schottky barrier diode according to claim 1, wherein the ohmic electrode (4) is formed by depositing a titanium layer, an aluminum layer, a nickel layer and a gold layer sequentially by an electron beam evaporation process at a part of the n-GaN epitaxial layer (3 b), and performing a heat treatment in a nitrogen atmosphere at 800 ℃ to 850 ℃ for 20 to 40 seconds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111413596.4A CN114335169B (en) | 2021-11-25 | 2021-11-25 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111413596.4A CN114335169B (en) | 2021-11-25 | 2021-11-25 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114335169A CN114335169A (en) | 2022-04-12 |
| CN114335169B true CN114335169B (en) | 2024-08-09 |
Family
ID=81046298
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111413596.4A Active CN114335169B (en) | 2021-11-25 | 2021-11-25 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114335169B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115360235B (en) * | 2022-08-09 | 2024-04-09 | 江南大学 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110931570A (en) * | 2019-12-13 | 2020-03-27 | 西安电子科技大学 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4076915B2 (en) * | 1995-03-17 | 2008-04-16 | 株式会社半導体エネルギー研究所 | Method for manufacturing display device |
| US6307244B1 (en) * | 1998-08-12 | 2001-10-23 | Rohm Co., Ltd. | Schottky barrier semiconductor device |
| JP4869576B2 (en) * | 2004-09-29 | 2012-02-08 | 新日本無線株式会社 | Nitride semiconductor device and manufacturing method thereof |
| US9455327B2 (en) * | 2014-06-06 | 2016-09-27 | Qorvo Us, Inc. | Schottky gated transistor with interfacial layer |
| CN108550622A (en) * | 2018-03-16 | 2018-09-18 | 扬州科讯威半导体有限公司 | A kind of gallium nitride schottky barrier diode and its manufacturing method |
| CN111293179A (en) * | 2018-12-10 | 2020-06-16 | 黄山学院 | Silicon-based gallium nitride Schottky diode and preparation method thereof |
| CN112216746B (en) * | 2019-07-11 | 2024-05-14 | 即思创意股份有限公司 | Silicon carbide semiconductor device |
| CN110600535A (en) * | 2019-09-11 | 2019-12-20 | 四川洪芯微科技有限公司 | Schottky diode chip and preparation method thereof |
| CN110828557A (en) * | 2019-09-30 | 2020-02-21 | 西安交通大学 | P-GaN ohmic contact electrode and preparation method and application thereof |
| CN115360235B (en) * | 2022-08-09 | 2024-04-09 | 江南大学 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
-
2021
- 2021-11-25 CN CN202111413596.4A patent/CN114335169B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110931570A (en) * | 2019-12-13 | 2020-03-27 | 西安电子科技大学 | Gallium nitride Schottky barrier diode and manufacturing method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114335169A (en) | 2022-04-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20110297957A1 (en) | Compound seminconductor structure | |
| CN111463326B (en) | Semiconductor device and method for manufacturing the same | |
| AU2020103598A4 (en) | Preparation method of gallium nitride-based photoelectric detector based on graphene insertion layer structure | |
| CN113054002B (en) | Enhanced high-mobility gallium nitride semiconductor device and preparation method thereof | |
| CN114335169B (en) | Gallium nitride Schottky barrier diode and manufacturing method thereof | |
| JP3603713B2 (en) | Method of growing group III nitride compound semiconductor film and group III nitride compound semiconductor device | |
| CN110600549B (en) | Enhanced AlGaN/GaN MOS-HEMT device structure and preparation method thereof | |
| CN111739931A (en) | Regrown GaN Schottky diode and manufacturing method thereof | |
| CN113675260A (en) | GaN Schottky diode based on linear graded doped drift layer and preparation method thereof | |
| JP3692867B2 (en) | Group III nitride compound semiconductor device | |
| CN112687527A (en) | Large-size SiC substrate low-stress GaN film and epitaxial growth method thereof | |
| CN116666428A (en) | Gallium nitride Schottky diode and preparation method thereof | |
| US20030160264A1 (en) | Hetero-junction semiconductor device and manufacturing method thereof | |
| CN110931547A (en) | HEMT device and preparation method thereof | |
| JP2004296701A (en) | Epitaxial substrate, semiconductor device and method for growing crystal for nitride-based semiconductor | |
| CN114597266A (en) | Lateral schottky barrier diode with hybrid P-type material ohmic cathode | |
| CN113270494B (en) | Double-gradient-channel gallium nitride-based vertical-structure radio frequency device and preparation method thereof | |
| TW202028549A (en) | Method of forming single- crystal group-iii nitride | |
| KR20140139890A (en) | Nitride semiconductor and method thereof | |
| JP7556401B2 (en) | How a transistor is manufactured | |
| CN112838006B (en) | Gallium nitride PIN diode and preparation method thereof | |
| CN114497185B (en) | Preparation method of carbon doped insulating layer, HEMT device and preparation method thereof | |
| JP3549151B2 (en) | Nitride-based compound semiconductor and method of manufacturing the same | |
| WO2008002521A2 (en) | Semiconductor heterojunction devices based on sic | |
| CN118016531A (en) | Method for improving secondary epitaxial surface morphology of Ga-containing alloy compound selected area and application |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |