CN111863959A - Vertical-structure high-electron-mobility transistor structure and manufacturing method thereof - Google Patents

Vertical-structure high-electron-mobility transistor structure and manufacturing method thereof Download PDF

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CN111863959A
CN111863959A CN202010519526.6A CN202010519526A CN111863959A CN 111863959 A CN111863959 A CN 111863959A CN 202010519526 A CN202010519526 A CN 202010519526A CN 111863959 A CN111863959 A CN 111863959A
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CN111863959B (en
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刘军林
吕全江
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Jiangsu University
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    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
    • H01L29/76—Unipolar devices, e.g. field effect transistors
    • H01L29/772—Field effect transistors
    • H01L29/778—Field effect transistors with two-dimensional charge carrier gas channel, e.g. HEMT ; with two-dimensional charge-carrier layer formed at a heterojunction interface
    • H01L29/7788—Vertical transistors
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    • 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
    • H01L29/0603—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 characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions
    • H01L29/0607—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 characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a 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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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
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    • H01L29/66409—Unipolar field-effect transistors
    • H01L29/66446—Unipolar field-effect transistors with an active layer made of a group 13/15 material, e.g. group 13/15 velocity modulation transistor [VMT], group 13/15 negative resistance FET [NERFET]
    • H01L29/66462—Unipolar field-effect transistors with an active layer made of a group 13/15 material, e.g. group 13/15 velocity modulation transistor [VMT], group 13/15 negative resistance FET [NERFET] with a heterojunction interface channel or gate, e.g. HFET, HIGFET, SISFET, HJFET, HEMT

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Abstract

The invention belongs to the technical field of semiconductors, and particularly relates to a vertical-structure high-electron-mobility transistor structure and a manufacturing method thereof. The transistor structure comprises from bottom to top: the high-voltage GaN-based HEMT device comprises a drain electrode, a substrate, a bonding metal layer, a drain ohmic contact metal layer, a high-resistance layer, a dislocation regulation structure, a GaN channel layer, an AlGaN barrier layer, a P-type layer, a passivation layer, a source electrode and a gate electrode, wherein a vertical conductive channel is arranged in the high-resistance layer right below the gate electrode, so that the drain ohmic contact metal layer is communicated with the GaN channel layer, and the dislocation regulation structure forms relative high resistance to other regions near a dislocation line, so that leakage current does not pass through a large amount of dislocation lines but is uniformly distributed in the cross section of the whole HEMT device under the condition that the AlGaN/GaN HEMT device bears high voltage, the breakdown performance is close to the theoretical breakdown strength of GaN, and the.

Description

Vertical-structure high-electron-mobility transistor structure and manufacturing method thereof
Technical Field
The invention belongs to the technical field of semiconductors, and particularly relates to an AlGaN/GaN high-electron-mobility transistor structure with a vertical structure and a manufacturing method thereof.
Background
Compared with the first and second generation semiconductor materials, the third generation semiconductor material GaN material has the advantages of large forbidden band width, high breakdown field intensity, large electron mobility, strong radiation resistance and the like, and has great development potential in the high-frequency and high-power fields of GaN-based high-electron mobility transistors, such as wireless communication base stations, radars, automotive electronics and the like. AlGaN/GaN High electron mobility transistor (AlGaN/GaN HEMT) structures appeared based on the phenomena described in T.Mimura et al (GaAs MOSFET for low-power-spaced applications,37th Device Research Conference, University of Colorado, Boulder, CO,1979) in 1975 and M.A.Khan et al (High electron mobility transistor based on a GaN/AlxGa1-xN junction, Applied Physics Letters,65(1994): 1121) 1123: the AlGaN and GaN heterostructure interface region exhibits exceptionally high electron mobility.
Since the advent of GaN HEMTs, breakdown voltage enhancement has been one of the difficulties. The breakdown voltage between the source and drain of a GaN HEMT is determined by several factors: the breakdown field strength of GaN, the structural design of the device, the characteristics of the heterostructure, the design of the insulating layer above the gate, source and drain, and the characteristics of the substrate material, etc. The common breakdown modes include (1) source-drain breakdown, (2) gate-drain breakdown, and (3) vertical breakdown. In the aspect of device structure, the back barrier double heterojunction can effectively inhibit the buffer layer from leaking and short channel effect, so that the breakdown voltage of the HEMT device is improved, the field plate modulation electric field is also an important means for improving the breakdown voltage of the HEMT device, and in addition, the aluminum oxide or silicon nitride and the like are used as a gate insulating layer or a surface passivation layer, so that the breakdown characteristic can be obviously improved. Introducing a high-resistance GaN layer before the channel GaN layer is also a common method for improving the breakdown voltage, and impurity elements such as Fe and C are usually doped into GaN to realize high resistance. Vertical GaN HEMTs have higher breakdown voltages than lateral GaN HEMTs, and are an important development direction for high-voltage HEMTs. Through continuous technical progress in recent years, the breakdown characteristic of the GaN-based HEMT is remarkably improved, however, the power device of over 1000V commercial power device still takes the SiC device as the main part at present, and the GaN device still cannot well meet the high-voltage and high-power requirements. This fact is in contradiction to the theoretically predicted breakdown characteristics. According to theoretical calculations, GaN has a higher breakdown voltage than SiC for the same on-resistance. When the device structure is well optimized, the important reason that the breakdown voltage of the GaN-based HEMT device is still far below the theoretical limit comes from the high dislocation density of the GaN material. The dislocation density of SiC has been up to 10 2/cm2Of order of magnitude, while GaN has dislocation densities as high as 10 due to heteroepitaxy8/cm2Of order, i.e.The dislocation density of the GaN substrate is 105/cm2In order of magnitude, still much higher than the dislocation density of SiC.
When a vertical structure AlGaN/GaN HEMT device bears high voltage, the electric field is mainly concentrated in the vertical direction, and the current direction is consistent with the dislocation line direction in GaN. The high-density dislocation lines become main channels for electric field concentration and electric leakage, so that AlGaN/GaN HEMT devices are easy to break down, and the characteristics of the AlGaN/GaN HEMT are far lower than theoretical values. It can be seen that the adverse effect brought by the high dislocation density is the problem that the breakdown characteristic of the existing vertical structure AlGaN/GaN HEMT device is far lower than the theoretical level.
Disclosure of Invention
The invention aims to provide a novel AlGaN/GaN high electron mobility transistor structure with a vertical structure and a manufacturing method thereof, wherein relative high resistance to other areas is formed near GaN dislocation by introducing a dislocation regulation structure, so that leakage current does not greatly pass through dislocation lines but is uniformly distributed in the cross section of the whole HEMT device when an AlGaN/GaN HEMT device bears high voltage, the breakdown performance is close to the GaN theoretical breakdown strength, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor structure is improved.
The purpose of the invention is realized as follows:
a vertical structure AlGaN/GaN high electron mobility transistor structure sequentially comprises from bottom to top: the structure comprises a drain electrode, a substrate, a bonding metal layer, a drain ohmic contact metal layer, a high-resistance layer, a dislocation regulation structure, a GaN channel layer, an AlGaN barrier layer, a P-type layer, a passivation layer, a source electrode and a grid electrode, and is characterized in that: be equipped with perpendicular electrically conductive passageway in the high resistant layer under the grid electrode, make drain electrode ohmic contact metal level and GaN channel layer UNICOM, dislocation regulation and control structure includes that inverted hexagonal taper hole formative layer, potential barrier regulation and control layer and inverted hexagonal taper hole merge the layer, inverted hexagonal taper hole formative layer forms inverted hexagonal taper hole in dislocation line department, potential barrier regulation and control layer forms the relative high resistance than region outside inverted hexagonal taper hole at inverted hexagonal taper hole lateral wall and inverted hexagonal taper hole awl bottom position, inverted hexagonal taper hole merges the layer will inverted hexagonal taper hole is filled and is leveled.
Furthermore, the vertical conductive channel is composed of a through hole in the high-resistance layer and a metal layer filled in the through hole, and the metal layer filled in the through hole is a drain ohmic contact metal layer or a separately deposited metal layer.
Furthermore, the vertical conductive channel is an n-type low-resistance region formed by Si ion implantation in the high-resistance layer.
Furthermore, the barrier control layer is not doped with Al on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pitxGa1-xN, Si-doped Al outside the reverse hexagonal pyramid-shaped pitsxGa1-xAnd N, wherein x is more than or equal to 0 and less than or equal to 0.3, and the region near the dislocation line in the inverted hexagonal cone-shaped pit becomes relatively high resistance by utilizing the Si doping difference, so that the leakage current of the AlGaN/GaN high electron mobility transistor device with the vertical structure is uniformly distributed in the cross section of the whole device without passing through a large amount of dislocation lines under the state of bearing high voltage, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
Furthermore, the barrier control layer is made of Al with the average Al component x at the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pitxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, wherein x is more than or equal to 0.4 and less than or equal to 1 and 0<y is less than or equal to 0.3, x/y is greater than or equal to 1.5, and the region near the dislocation line in the inverted hexagonal cone-shaped pit becomes relatively high resistance by utilizing Al component difference, so that the leakage current of the AlGaN/GaN high electron mobility transistor device with the vertical structure is uniformly distributed in the cross section of the whole device without passing through a large amount of dislocation lines under the state of bearing high voltage, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
Furthermore, the barrier control layer has a thickness h at the side wall of the inverted hexagonal pyramid-shaped pitpAl of (2)xGa1-xN, the thickness of the region outside the inverted hexagonal pyramid-shaped pit is hcAl of (2)xGa1-xN, wherein x is more than or equal to 0 and less than or equal to 1, and hp/hcAnd the thickness difference is used for enabling the area near the dislocation line in the inverted hexagonal cone-shaped pit to be relatively high-resistance, so that the leakage current does not greatly pass through the dislocation line but is uniformly distributed in the cross section of the whole device when the vertical structure AlGaN/GaN high electron mobility transistor device bears high voltage, and the breakdown voltage of the vertical structure AlGaN/GaN high electron mobility transistor is improved.
Furthermore, the barrier control layer is one or a combination of the barrier control layers, that is, the region near the dislocation line in the inverted hexagonal pyramidal pit becomes relatively high resistance by using one or a combination of Si doping difference, Al composition difference and thickness difference.
Further, the outer edge of the through hole in the high-resistance layer is smaller than the outer edge of the gate, and the distance between the outer edge of the through hole in the high-resistance layer and the outer edge of the gate is defined as Lg，1μm≤Lg≤10μm。
Preferably, LgThe difference with the thickness of the high-resistance layer is less than 1 micron.
Furthermore, an AlN insert layer is arranged between the GaN channel layer and the AlGaN barrier layer, the thickness of the AlN insert layer is 0-5 nm, and when the thickness of the AlN doped layer is 0nm, the AlN insert layer is removed equivalently.
Furthermore, the high-resistance layer is GaN doped with C elements, GaN doped with Fe elements, AlGaN doped with C elements or AlGaN doped with Fe elements, and the thickness of the high-resistance layer is 1-10 mu m.
Furthermore, the P-type layer is GaN doped with Mg element or AlGaN doped with Mg element.
Further, the substrate is a material with good electrical and thermal conductivity, such as Si, Ge, Cu alloy, etc., but not limited thereto.
Furthermore, the GaN channel layer is an unintentionally doped GaN layer, and the thickness of the GaN channel layer is 100 nm-500 nm.
Further, the AlGaN barrier layer is AlxGa(1-x)The thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
A manufacturing method of a vertical structure AlGaN/GaN high electron mobility transistor comprises the following steps:
(1) providing a substrate, and sequentially growing an HEMT epitaxial film comprising a buffer layer, a high-resistance layer, a dislocation regulation structure, a GaN channel layer, an AlN insertion layer, an AlGaN barrier layer and a P-type layer on the substrate;
(2) etching off the P-type layer of the region outside the grid electrode to be manufactured on the HEMT epitaxial film by a photoetching technology;
(3) growing a passivation layer on the AlGaN barrier layer and the P-type layer;
(4) etching the passivation layer at the position of the source electrode to be manufactured by using a photoetching technology, and manufacturing the source electrode by using a stripping technology;
(5) Etching the passivation layer above the P-type layer by using a photoetching technology, and then manufacturing a grid electrode by using a stripping technology;
(6) manufacturing an adhesive layer on the surface of the HEMT epitaxial film with the source electrode and the grid electrode;
(7) providing a transition substrate, manufacturing a bonding layer on the front surface of the transition substrate, and manufacturing a protective layer on the back surface of the transition substrate;
(8) adhering the HEMT epitaxial film with the source electrode and the gate electrode and the transition substrate together by using the bonding layer, etching off the substrate and the buffer layer to obtain the transition HEMT epitaxial film, wherein in the process of etching the substrate and the buffer layer, the protective layer on the reverse side of the transition substrate can ensure that the transition substrate is not etched;
(9) forming a vertical conductive channel in the high-resistance layer;
(10) sequentially depositing a drain electrode ohmic contact layer and a bonding metal layer on the transition HEMT epitaxial film with the vertical conductive channel;
(11) providing a substrate, depositing a bonding metal layer on the front surface of the substrate, depositing a drain metal layer on the back surface of the substrate, and binding the transition HEMT epitaxial film and the substrate together by using the bonding metal layer;
(12) and removing the protective layer, the transition substrate and the bonding layer to obtain the AlGaN/GaN high-electron-mobility transistor with the vertical structure.
Furthermore, in step (9), the method for forming the vertical conductive channel in the high resistance layer includes: and corroding a through hole in the high-resistance layer, filling metal in the through hole, or reserving the through hole, and filling the through hole when the drain ohmic contact layer and the bonding metal layer are deposited.
Further, in step (9), the method for forming the vertical conductive channel in the high resistance layer further includes: and an n-type low resistance region formed by Si ion implantation in the high resistance layer.
Further, the dislocation regulation structure can be realized by Si doping regulation near the dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing undoped AlxGa1-xN layer of Al on the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN thickness and Al outside the inverted hexagonal pyramid-shaped pitxGa1-xThe thickness ratio of N is 0.8-1, and x is more than or equal to 0 and less than or equal to 0.3;
(3) growing Si-doped AlxGa1-xN layer of Al on the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN thickness and Al thickness of the region outside the inverted hexagonal conical pitxGa1-xThe ratio of N is 0.2-0.4, x is more than or equal to 0 and less than or equal to 0.3, and the concentration of doped Si is 1 x 1018～1×1020cm-3；
(4) Decomposition of Si-doped AlxGa1-xN layer to make the decomposition rate of the side wall of the inverted hexagonal pyramid-shaped pit the same as that of the region outside the inverted hexagonal pyramid-shaped pit, and controlling the Si Al doping of the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN is completely decomposed to ensure that the side wall of the inverted hexagonal cone-shaped pit is doped with SiAlxGa1-xComplete decomposition of N, or proper over-decomposition to make Si-doped AlxGa1-xUndoped Al under NxGa1-xN is also partially decomposed and Si Al is doped in the region outside the inverted hexagonal pyramidal pitsxGa1-xReserving an N layer;
(5) growing undoped Al xGa1-xN layer of Al on the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN thickness and Al outside the inverted hexagonal pyramid-shaped pitxGa1-xThe ratio of the thickness of N is 0.8 to 1,0≤x≤0.3；
(6) repeating the steps (3), (4) and (5) for multiple times to form a potential barrier regulation layer, wherein the repetition times are more than 2 times;
(7) growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
through the steps (1) to (7), the dislocation regulation structure with no doping in the inverted hexagonal conical pit and Si doping in the region outside the inverted hexagonal conical pit is obtained, the potential barrier regulation layer forms relative high resistance in the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit compared with the region outside the inverted hexagonal conical pit, and Si-doped Al can be regulatedxGa1-xThe Si doping concentration of the N layer is used for regulating and controlling the relative resistance between the position of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit.
Further, the dislocation regulation structure can be realized by regulating and controlling the Al component near the dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing an AlN layer to make the thickness of the side wall AlN of the inverted hexagonal conical pit equal to that of the AlN of the region outside the inverted hexagonal conical pit, wherein the thickness of the side wall AlN of the inverted hexagonal conical pit is 0.2-0.4 nm;
(3) Growing a GaN layer, wherein the ratio of the thickness of GaN on the side wall of the inverted hexagonal conical pit to the thickness of GaN on the region outside the inverted hexagonal conical pit is 0.2-0.3, and the thickness of GaN on the side wall of the inverted hexagonal conical pit is 0.2-0.4 nm;
(4) repeating the steps (2) and (3) for multiple times to form a potential barrier regulation layer, wherein the repetition times are more than 2 times;
(5) growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
because the AlN and the GaN which grow in each step are very thin, the formed AlN/GaN laminated layer can be approximately regarded as an AlGaN material, the average Al component of the AlGaN material is expressed by the average Al component, a dislocation regulating structure with high average Al component on the side wall of the inverted hexagonal conical pit and low average Al component in the region outside the inverted hexagonal conical pit is obtained through the steps (1) to (5), and the positions of the potential barrier regulating layer on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit are the average Al component xAlxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, regulating and controlling the difference between the average Al component of the side wall of the inverted hexagonal conical pit and the average Al component of the region outside the inverted hexagonal conical pit by regulating the thickness of the AlN layer and the GaN layer on the side wall of the inverted hexagonal conical pit and the region outside the inverted hexagonal conical pit, so that x is more than or equal to 0.4 and less than or equal to 1, and 0 <y is less than or equal to 0.3, and x/y is greater than or equal to 1.5, so as to regulate and control the relative resistance between the inverted hexagonal cone-shaped pit and the region outside the inverted hexagonal cone-shaped pit.
Further, the dislocation regulation structure can be realized by regulating the appearance near the dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing undoped AlxGa1-xThe N layer is used as a barrier regulation layer and is an inverted hexagonal conical pit side wall AlxGa1-xN has a thickness of hpOuter region Al of inverted hexagonal pyramidal pitxGa1-xN has a thickness of hc，0≤x≤1，hp/hc≥2；
(3) Growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
through the steps (1) to (3), the barrier control layer with thick side wall of the inverted hexagonal conical pit and thin thickness of the area outside the inverted hexagonal conical pit is obtained, the relative high resistance of the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit is formed compared with the relative high resistance of the area outside the inverted hexagonal conical pit, and the relative resistance of the position of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit can be controlled by adjusting the thickness ratio of the side wall of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit.
Further, the dislocation regulation structure can be realized by two or three combination regulation of Si doping, Al components and appearance near the dislocation line.
Further, the substrate is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate.
Further, the adhesive layer may be a thermosetting adhesive, a hot-melt adhesive, a photo-curable organic glue, paraffin or a low-melting metal.
Compared with the prior art, the invention has the following beneficial effects:
when a vertical structure AlGaN/GaN HEMT device bears high voltage, the electric field is mainly concentrated in the vertical direction, and the current direction is consistent with the dislocation line direction in GaN. The high-density dislocation lines become main channels for electric field concentration and electric leakage, so that AlGaN/GaN HEMT devices are easy to break down, and the characteristics of the AlGaN/GaN HEMT are far lower than theoretical values. According to the AlGaN/GaN high-electron-mobility transistor structure with the vertical structure, the dislocation regulation structure is introduced, and the relative high resistance to the rest area is formed near the GaN dislocation line, so that leakage current does not greatly pass through the dislocation line but is uniformly distributed in the cross section of the whole HEMT device when the AlGaN/GaN HEMT device bears high voltage, the breakdown performance is close to the theoretical breakdown strength of GaN, and the breakdown voltage of the AlGaN/GaN HEMT device is improved.
Meanwhile, compared with the conventional AlGaN/GaN high-electron-mobility transistor with the vertical structure, the structure provided by the invention does not need a secondary epitaxy process, and fundamentally eliminates adverse effects brought by interface pollution brought by secondary epitaxy.
The outer edge of the through hole in the high-resistance layer is smaller than the outer edge of the grid, a proper distance is kept between the outer edge of the through hole in the high-resistance layer and the outer edge of the grid, and the optimal size of the distance is close to the thickness of the high-resistance layer, so that when the vertical structure AlGaN/GaN high electron mobility transistor bears high voltage, an electric field can be uniformly distributed at each position instead of being mainly distributed in the area between the outer edge of the grid and the outer edge of the through hole in the high-resistance layer, and the breakdown voltage of the vertical structure AlGaN/GaN high electron mobility transistor is remarkably improved.
The method for manufacturing the vertical structure AlGaN/GaN high electron mobility transistor needs to remove the growth substrate, and selects the substrate with good electric conduction and heat conduction as the electric conduction and heat dissipation channel, so that on one hand, the substrate with high quality GaN and low price can be selected when the growth substrate is selected, and the electric conduction and heat conduction performance, such as a sapphire substrate, does not need to be considered, and on the other hand, the substrate can also be selected from materials with good heat conduction and electric conduction and low price, such as Cu, Cu alloy, Si and the like, so that the substrate selection is more flexible, and the comprehensive cost performance of the device is further improved.
Drawings
FIG. 1 is a schematic cross-sectional view of a vertical AlGaN/GaN HEMT structure of the present invention.
Fig. 2 is a schematic view of step 1 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3, and 4 of the present invention.
Fig. 3 is a schematic diagram of step 2 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3, and 4 of the present invention.
Fig. 4 is a schematic diagram of step 3 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 5 is a schematic diagram of step 4 of the method for manufacturing a vertical AlGaN/GaN hemt in embodiments 1, 2, 3 and 4 of the present invention.
Fig. 6 is a schematic diagram of step 5 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 7 is a schematic diagram of step 6 of the method for fabricating a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 8 is a schematic diagram of step 7 of the method for fabricating a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 9 is a schematic diagram of step 8 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 10 is a schematic diagram of step 9 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 11 is a schematic diagram of step 10 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 12 is a schematic diagram of step 11 of the method for manufacturing a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 13 is a schematic diagram of step 12 of the method for fabricating a vertical AlGaN/GaN hemt according to embodiments 1, 2, 3 and 4 of the present invention.
Fig. 14 is a schematic cross-sectional view of a step 1 of growing a dislocation-regulating structure in a vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 15 is a schematic perspective view of the vertical AlGaN/GaN high electron mobility transistor according to embodiment 1 after the end of the step 1 for growing the dislocation controlling structure.
Fig. 16 is a schematic cross-sectional view of a step 2 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 1 of the present invention.
Fig. 17 is a schematic cross-sectional view of step 3 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 18 is a schematic cross-sectional view of the dislocation regulating structure growing step 4 in the vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 19 is a schematic cross-sectional view of step 5 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 20 is a schematic cross-sectional view of step 6 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 21 is a schematic cross-sectional view of step 7 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 1 of the present invention.
Fig. 22 is a schematic cross-sectional view of a step 1 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 2 of the present invention.
Fig. 23 is a schematic cross-sectional view of a step 2 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 2 of the present invention.
Fig. 24 is a schematic cross-sectional view of a step 3 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 2 of the present invention.
Fig. 25 is a schematic cross-sectional view of the dislocation regulating structure growing step 4 in the vertical AlGaN/GaN hemt in embodiment 2 of the present invention.
Fig. 26 is a schematic cross-sectional view of a step 5 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt in embodiment 2 of the present invention.
Fig. 27 is a schematic cross-sectional view of a step 1 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 3 of the present invention.
Fig. 28 is a schematic cross-sectional view of a step 2 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 3 of the present invention.
Fig. 29 is a schematic cross-sectional view of a step 3 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 3 of the present invention.
Fig. 30 is a schematic cross-sectional view of a step 1 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 4 of the present invention.
Fig. 31 is a schematic cross-sectional view of a step 2 of growing a dislocation regulating structure in a vertical AlGaN/GaN hemt according to embodiment 4 of the present invention.
Illustration of the drawings: 100-HEMT epitaxial film, 101-drain electrode, 102-substrate, 103-bonding metal layer, 104-drain ohmic contact metal layer, 105-high resistance layer, 106-dislocation regulation structure, 107-GaN channel layer, 108-AlN insertion layer, 109-AlGaN barrier layer, 110-P type layer, 111-passivation layer, 112-source electrode, 113-gate electrode, 114-vertical conductive channel, 115-substrate, 116-buffer layer, 117-bonding layer, 118-transition substrate, 119-protection layer, 120-transition HEMT epitaxial film, 130-dislocation line, 140-inverted hexagonal cone pit, 200-barrier regulation layer, 201-inverted hexagonal pit forming layer, 202-undoped Al-doped layer xGa1-xN layer, 203-Si-doped AlxGa1-xAn N layer, a 204-inverted hexagonal pyramid-shaped pit merging layer, a 300-barrier regulation layer, a 301-inverted hexagonal pyramid-shaped pit forming layer, a 302-AlN layer, a 303-GaN layer, a 304-inverted hexagonal pyramid-shaped pit merging layer, a 401-inverted hexagonal pyramid-shaped pit forming layer, a 402-barrier regulation layer, a 403-inverted hexagonal pyramid-shaped pit forming layer, a 501-inverted hexagonal pyramid-shaped pit forming layer, and a 502-barrier regulation layer.
Detailed Description
The invention is further described below with reference to the figures and examples. It should be noted that the dislocation lines and the inverted hexagonal cone shaped pits thereof mentioned in the vertical structure AlGaN/GaN high electron mobility transistor structure of the present invention cannot be represented in the same sub-diagram in terms of number and size as those of the vertical structure AlGaN/GaN high electron mobility transistor structure of the present invention, and therefore, for better illustration, the dislocation regulating structure is taken out separately and is illustrated by a schematic diagram, as shown in fig. 14 to fig. 31.
Example 1:
fig. 1 is a schematic diagram of a vertical AlGaN/GaN high electron mobility transistor structure according to the present invention, which sequentially includes, from bottom to top: the semiconductor device comprises a drain electrode 101, a substrate 102, a bonding metal layer 103, a drain ohmic contact metal layer 104, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlGaN barrier layer 109, a P-type layer 110, a passivation layer 111, a source electrode 112 and a gate electrode 113, and is characterized in that: a vertical conductive channel 114 is arranged in the high resistance layer right below the gate electrode 113, so that the drain ohmic contact metal layer 104 is communicated with the GaN channel layer 107; as shown in fig. 21, the dislocation regulating structure includes an inverted hexagonal pyramid-shaped pit forming layer 201, a potential barrier regulating layer 200, and an inverted hexagonal pyramid-shaped pit merging layer 204, wherein the inverted hexagonal pyramid-shaped pit forming layer 201 forms an inverted hexagonal pyramid-shaped pit 140 at a dislocation line 130, the potential barrier regulating layer forms a relatively high resistance at a sidewall of the inverted hexagonal pyramid-shaped pit and a bottom of the inverted hexagonal pyramid-shaped pit compared to a region outside the inverted hexagonal pyramid-shaped pit, and the inverted hexagonal pyramid-shaped pit merging layer 204 fills the inverted hexagonal pyramid-shaped pit.
The barrier control layer 200 is not doped with Al on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pitxGa1-xN in the shape of an inverted hexagonal coneThe region outside the pit is Si-doped AlxGa1-xAnd N, wherein x is more than or equal to 0 and less than or equal to 0.3, and the region near the dislocation line in the inverted hexagonal cone-shaped pit becomes relatively high resistance by utilizing the Si doping difference, so that the leakage current of the AlGaN/GaN high electron mobility transistor device with the vertical structure is uniformly distributed in the cross section of the whole device without passing through a large amount of dislocation lines under the state of bearing high voltage, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
The vertical conductive channel 114 is formed by a through hole in the high resistance layer and a metal layer filled in the through hole, and the metal layer filled in the through hole may be the drain ohmic contact metal layer 104 or a separately deposited metal layer.
The vertical conductive via 114 may also be an n-type low resistance region formed within the high resistance layer using Si ion implantation.
The outer edge of the through hole in the high resistance layer 105 is smaller than the outer edge of the gate electrode 113, and the distance between the outer edge of the through hole in the high resistance layer 105 and the outer edge of the gate electrode 113 is defined as Lg，1μm≤LgLess than or equal to 10 mu m. Preferably, LgThe difference with the thickness of the high-resistance layer is less than 1 micron.
An AlN insert layer 108 is provided between the GaN channel layer 107 and the AlGaN barrier layer 109, the AlN insert layer 108 has a thickness of 0 to 5nm, and when the AlN insert layer 108 has a thickness of 0nm, the AlN insert layer 108 is removed.
The high-resistance layer 105 is GaN or AlGaN doped with C or Fe, and the thickness of the high-resistance layer is 1-10 μm.
The P-type layer 110 is P-GaN or P-AlGaN doped with Mg element.
The substrate 102 is a material with good electrical and thermal conductivity, such as Si, Ge, Cu alloy, etc., but not limited thereto.
The GaN channel layer 107 is an unintentionally doped GaN layer and has a thickness of 100nm to 500 nm.
The AlGaN barrier layer 109 is AlxGa1-xThe thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
A manufacturing method of a vertical structure AlGaN/GaN high electron mobility transistor comprises the following steps:
(1) as shown in fig. 2, a substrate 115 is provided, and a HEMT epitaxial thin film 100 including a buffer layer 116, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlN layer 108, an AlGaN barrier layer 109, and a P-type layer 110 is grown on the substrate in sequence;
(2) as shown in fig. 3, the P-type layer outside the region where the gate electrode is to be formed is etched away from the HEMT epitaxial film 100 by a photolithography and etching technique;
(3) as shown in fig. 4, a passivation layer 111 is grown on the AlGaN barrier layer 109 and the P-type layer 110;
(4) As shown in fig. 5, the passivation layer 111 at the position where the source electrode 112 is to be formed is etched by using a photolithography and etching technique, and then the source electrode 112 is formed by using a lift-off technique;
(5) as shown in fig. 6, the passivation layer 111 above the P-type layer 110 is etched away by using a photolithography and etching technique, and then the gate electrode 113 is formed by using a lift-off technique;
(6) as shown in fig. 7, an adhesive layer 117 is formed on the surface of the HEMT epitaxial thin film on which the source electrode 112 and the gate electrode 113 are formed;
(7) as shown in fig. 8, providing a transition substrate 118, forming an adhesive layer 117 on a front surface of the transition substrate, and forming a protective layer 119 on a back surface of the transition substrate;
(8) as shown in fig. 9, the HEMT epitaxial thin film on which the source electrode 112 and the gate electrode 113 are fabricated is bonded to the transition substrate 118 by using the adhesive layer 117, the substrate 115 and the buffer layer 116 are etched away to obtain the transition HEMT epitaxial thin film 120, and the protective layer 119 on the reverse side of the transition substrate 118 can ensure that the transition substrate 118 is not etched in the process of etching the substrate 115 and the buffer layer 116;
(9) as shown in fig. 10, vertical conductive vias 114 are formed in the high-resistance layer 105;
(10) as shown in fig. 11, a drain ohmic contact layer 104 and a bonding metal layer 103 are sequentially deposited on the transition HEMT epitaxial film where the vertical conductive path 114 is formed;
(11) As shown in fig. 12, a substrate 102 is provided, a bonding metal layer 103 is deposited on the front surface of the substrate, a drain electrode 101 metal layer is deposited on the back surface of the substrate, and the transition HEMT epitaxial film 120 and the substrate 102 are bonded together by using the bonding metal layer 103;
(12) as shown in fig. 13, the protective layer 119, the transition substrate 118, and the adhesive layer 117 are removed, and a vertical structure AlGaN/GaN high electron mobility transistor is obtained.
The dislocation regulation structure is realized by regulating and controlling Si doping near dislocations, and the growth method comprises the following steps:
(1) as shown in fig. 14, an inverted hexagonal pyramidal pit-forming layer 201 is grown, inverted hexagonal pyramidal pits 140 are formed at the dislocation lines 130, the cross-section of the inverted hexagonal pyramidal pits 140 is V-shaped, and as shown in the perspective view of the inverted hexagonal pyramidal pit-forming layer in fig. 15, the inverted hexagonal pyramidal pits 140 are pits of inverted hexagonal pyramidal structure;
(2) as shown in fig. 16, undoped Al is grownxGa1-xN layers 202, the ratio of the thickness of the side wall of the inverted hexagonal pyramidal pit 140 to the thickness of the region outside the inverted hexagonal pyramidal pit 140 is 0.8-1, and x is more than or equal to 0 and less than or equal to 0.3;
(3) as shown in FIG. 17, Si-doped Al is grownxGa1-xN layer 203, the ratio of the thickness of the sidewall of inverted hexagonal pyramidal pit 140 to the thickness of the region outside inverted hexagonal pyramidal pit 140 is 0.2-0.4, x is 0-0.3, and the concentration of doped Si is 1 × 10 18～1×1020cm-3；
(4) As shown in FIG. 18, Si-doped Al is decomposedxGa1-xN layer 203 for making the decomposition rate of the sidewall of the inverted hexagonal pyramid-shaped pit 140 the same as that of the region outside the inverted hexagonal pyramid-shaped pit 140 and controlling the Si Al doping of the sidewall of the inverted hexagonal pyramid-shaped pit 140xGa1-xN is completely decomposed to ensure that the sidewalls of the inverted hexagonal pyramid-shaped pits 140 are doped with Si AlxGa1-xN is completely decomposed and can be properly over-decomposed to make Si-doped AlxGa1-xUndoped Al under N layer 203xGa1-x The N layer 202 is also partially decomposed and Si-doped Al is formed in the region outside the reverse hexagonal pyramid-shaped pits 140xGa1- xN203 layer reservation;
(5) as shown in FIG. 19, undoped Al is grownxGa1-xN layers 202, the ratio of the thickness of the side wall of the inverted hexagonal pyramidal pit 140 to the thickness of the region outside the inverted hexagonal pyramidal pit 140 is 0.8-1, and x is more than or equal to 0 and less than or equal to 0.3;
(6) as shown in fig. 20, the steps (3), (4), and (5) are repeated for a plurality of times to form the barrier control layer 200, wherein the repetition time is more than 2 times;
(7) as shown in fig. 21, an inverted hexagonal pyramidal pit-merging layer 204 is grown to fill the inverted hexagonal pyramidal pits 140;
through the steps (1) to (7), the dislocation regulating structure in which the regions outside the inverted hexagonal pyramid-shaped pits are not doped and Si is doped is obtained as shown in fig. 21, and the potential barrier regulating layer 200 forms a relatively higher resistance at the side walls of the inverted hexagonal pyramid-shaped pits and the bottom of the inverted hexagonal pyramid-shaped pits than the regions outside the inverted hexagonal pyramid-shaped pits, and can be adjusted to be doped with Si Al as shown in fig. 21 xGa1-xThe Si doping concentration of the N layer 203 is used to control the relative resistance between the position of the inverted hexagonal pyramid-shaped pit and the region outside the inverted hexagonal pyramid-shaped pit.
The method for forming the vertical conductive channel 114 in the high resistance layer 105 includes: a via hole is etched in the high-resistance layer 105, and metal is filled in the via hole, or the via hole may be filled when the drain ohmic contact layer 104 and the bonding metal layer 103 are deposited.
The method of forming the vertical conductive via 114 in the high resistance layer 105 further includes: an n-type low resistance region is formed by Si ion implantation in the high resistance layer 105.
The substrate 115 is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate.
The adhesive layer 117 may be a thermosetting adhesive, a hot-melt adhesive, a photo-curable organic adhesive, paraffin, or a low-melting metal.
In this embodiment, as shown in fig. 1, in the vertical AlGaN/GaN high electron mobility transistor, the dislocation regulation structure adopts a method of regulating Si doping, so that the sidewall and the bottom of the inverted hexagonal conical pit of the barrier regulation layer are not doped with AlxGa1-xN, Si-doped Al outside the reverse hexagonal pyramid-shaped pitsxGa1-xN, the region near the dislocation line in the inverted hexagonal pyramid-shaped pit becomes relatively high resistance by utilizing the Si doping difference, so that the leakage current of the AlGaN/GaN HEMT device with the vertical structure does not greatly pass through the dislocation line but is uniformly distributed to the whole device under the state of bearing high voltage In the cross section, the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
Example 2:
fig. 1 is a schematic diagram of a vertical AlGaN/GaN high electron mobility transistor structure according to the present invention, which sequentially includes, from bottom to top: the semiconductor device comprises a drain electrode 101, a substrate 102, a bonding metal layer 103, a drain ohmic contact metal layer 104, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlGaN barrier layer 109, a P-type layer 110, a passivation layer 111, a source electrode 112 and a gate electrode 113, and is characterized in that: a vertical conductive channel 114 is arranged in the high resistance layer right below the gate electrode 113, so that the drain ohmic contact metal layer 104 is communicated with the GaN channel layer 107; as shown in fig. 26, the dislocation regulating structure includes an inverted hexagonal pyramid-shaped pit forming layer 301, a potential barrier regulating layer 300, and an inverted hexagonal pyramid-shaped pit merging layer 304, wherein the inverted hexagonal pyramid-shaped pit forming layer 301 forms an inverted hexagonal pyramid-shaped pit 140 at the dislocation line 130, the potential barrier regulating layer forms a relatively high resistance at the sidewall of the inverted hexagonal pyramid-shaped pit and the bottom of the inverted hexagonal pyramid-shaped pit compared to the region outside the inverted hexagonal pyramid-shaped pit, and the inverted hexagonal pyramid-shaped pit merging layer 304 fills the inverted hexagonal pyramid-shaped pit.
The barrier regulation and control layer is arranged on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit and is made of Al with an average Al component xxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, wherein x is more than or equal to 0.4 and less than or equal to 1 and 0<y is less than or equal to 0.3, x/y is greater than or equal to 1.5, and the region near the dislocation line in the inverted hexagonal cone-shaped pit becomes relatively high resistance by utilizing Al component difference, so that the leakage current of the AlGaN/GaN high electron mobility transistor device with the vertical structure is uniformly distributed in the cross section of the whole device without passing through a large amount of dislocation lines under the state of bearing high voltage, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
The vertical conductive channel 114 is formed by a through hole in the high resistance layer and a metal layer filled in the through hole, and the metal layer filled in the through hole may be the drain ohmic contact metal layer 104 or a separately deposited metal layer.
The vertical conductive via 114 may also be an n-type low resistance region formed within the high resistance layer 105 using Si ion implantation.
The outer edge of the through hole in the high resistance layer 105 is smaller than the outer edge of the gate electrode 113, and the distance between the outer edge of the through hole in the high resistance layer 105 and the outer edge of the gate electrode 113 is defined as L g，1μm≤LgLess than or equal to 10 mu m. Preferably, LgThe difference with the thickness of the high-resistance layer is less than 1 micron.
An AlN insert layer 108 is arranged between the GaN channel layer 107 and the AlGaN barrier layer 109, the AlN insert layer has a thickness of 0-5 nm, and when the AlN insert layer has a thickness of 0nm, the AlN insert layer is removed.
The high-resistance layer 105 is GaN or AlGaN doped with C or Fe, and the thickness of the high-resistance layer is 1-10 μm.
The P-type layer 110 is P-GaN or P-AlGaN doped with Mg element.
The substrate 102 is a material with good electrical and thermal conductivity, such as Si, Ge, Cu alloy, etc., but not limited thereto.
The GaN channel layer 107 is an unintentionally doped GaN layer and has a thickness of 100nm to 500 nm.
The AlGaN barrier layer 109 is AlxGa1-xThe thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
A manufacturing method of a vertical structure AlGaN/GaN high electron mobility transistor comprises the following steps:
(1) as shown in fig. 2, a substrate 115 is provided, and a HEMT epitaxial thin film 100 including a buffer layer 116, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlN layer 108, an AlGaN barrier layer 109, and a P-type layer 110 is grown on the substrate in sequence;
(2) as shown in fig. 3, the P-type layer outside the region where the gate electrode is to be formed is etched away from the HEMT epitaxial film 100 by a photolithography and etching technique;
(3) As shown in fig. 4, a passivation layer 111 is grown on the AlGaN barrier layer 109 and the P-type layer 110;
(4) as shown in fig. 5, the passivation layer at the position where the source electrode 112 is to be formed is etched by using a photolithography and etching technique, and then the source electrode 112 is formed by using a lift-off technique;
(5) as shown in fig. 6, the passivation layer 111 above the P-type layer 110 is etched away by using a photolithography and etching technique, and then the gate electrode 113 is formed by using a lift-off technique;
(6) as shown in fig. 7, an adhesive layer 117 is formed on the surface of the HEMT epitaxial thin film 100 on which the source electrode 112 and the gate electrode 113 are formed;
(7) as shown in fig. 8, providing a transition substrate 118, forming an adhesive layer 117 on a front surface of the transition substrate, and forming a protective layer 119 on a back surface of the transition substrate;
(8) as shown in fig. 9, the HEMT epitaxial thin film 100 on which the source electrode 112 and the gate electrode 113 are fabricated is bonded to the transition substrate 118 by using the adhesive layer 117, the substrate 115 and the buffer layer 116 are etched away to obtain the transition HEMT epitaxial thin film 120, and the protective layer 119 on the reverse side of the transition substrate 118 can ensure that the transition substrate 118 is not etched in the process of etching the substrate 115 and the buffer layer 116;
(9) as shown in fig. 10, vertical conductive vias 114 are formed in the high-resistance layer 105;
(10) as shown in fig. 11, a drain ohmic contact layer 104, a bonding metal layer 103 are sequentially deposited on the transition HEMT epitaxial thin film 120 on which the vertical conductive channel 114 is formed;
(11) As shown in fig. 12, a substrate 102 is provided, a bonding metal layer 103 is deposited on the front surface of the substrate, a drain electrode 101 metal layer is deposited on the back surface of the substrate, and the transition HEMT epitaxial film 120 and the substrate 102 are bonded together by using the bonding metal layer 103;
(12) as shown in fig. 13, the protective layer 119, the transition substrate 118, and the adhesive layer 117 are removed, and a vertical structure AlGaN/GaN high electron mobility transistor is obtained.
The dislocation regulation structure is realized by regulating and controlling Al components near dislocations, and the growth method comprises the following steps:
(1) as shown in fig. 22, an inverted hexagonal pyramidal pit-forming layer 301 is grown, and inverted hexagonal pyramidal pits 140 are formed at the dislocation lines 130;
(2) growing an AlN layer 302 to make the thickness of the side wall AlN of the inverted hexagonal conical pit equal to that of the AlN of the region outside the inverted hexagonal conical pit, wherein the thickness of the side wall AlN of the inverted hexagonal conical pit is 0.2-0.4 nm;
(3) growing a GaN layer 303, wherein the ratio of the thickness of GaN on the side wall of the inverted hexagonal conical pit to the thickness of GaN on the region outside the inverted hexagonal conical pit is 0.2-0.3, and the thickness of GaN on the side wall of the inverted hexagonal conical pit is 0.2-0.4 nm;
(4) repeating the steps (2) and (3) for multiple times to form a potential barrier regulation layer 300, wherein the repetition times are more than 2 times;
(5) growing a combined layer 304 of the inverted hexagonal pyramidal pits to fill and level the inverted hexagonal pyramidal pits;
Through the above steps (1) to (5), a dislocation regulating structure in which the average Al composition of the sidewall of the inverted hexagonal pyramid-shaped pit is high and the average Al composition of the region outside the inverted hexagonal pyramid-shaped pit is low as shown in fig. 26 is obtained, and the potential barrier regulating layer 300 is located at the average Al composition x of the sidewall of the inverted hexagonal pyramid-shaped pit and the bottom of the inverted hexagonal pyramid-shaped pitxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, regulating and controlling the difference between the average Al component of the side wall of the inverted hexagonal conical pit and the average Al component of the region outside the inverted hexagonal conical pit by regulating the thickness of the AlN layer and the GaN layer on the side wall of the inverted hexagonal conical pit and the region outside the inverted hexagonal conical pit, so that x is more than or equal to 0.4 and less than or equal to 1, and 0<y is less than or equal to 0.3, and x/y is greater than or equal to 1.5, so as to regulate and control the relative resistance between the inverted hexagonal cone-shaped pit and the region outside the inverted hexagonal cone-shaped pit.
The method for forming the vertical conductive channel 114 in the high resistance layer 105 includes: and etching a through hole in the high-resistance layer, filling metal in the through hole, and filling the through hole when the drain electrode ohmic contact layer 104 and the bonding metal layer 103 are deposited.
The method of forming the vertical conductive via 114 in the high resistance layer 105 further includes: and an n-type low resistance region formed by Si ion implantation in the high resistance layer.
The substrate 115 is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate.
The adhesive layer 117 may be a thermosetting adhesive, a hot-melt adhesive, a photo-curable organic adhesive, paraffin, or a low-melting metal.
In this embodiment, as shown in fig. 1, in the vertical AlGaN/GaN high electron mobility transistor, the dislocation control structure is adoptedThe method for regulating and controlling the Al component makes the barrier regulating and controlling layer on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit be the Al with the average Al component xxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yAnd N, the area near the dislocation line in the inverted hexagonal cone-shaped pit becomes relatively high resistance by utilizing the difference of Al components, so that the leakage current of the AlGaN/GaN high-electron-mobility transistor device with the vertical structure does not greatly pass through the dislocation line but is uniformly distributed in the cross section of the whole device under the state of bearing high voltage, and the breakdown voltage of the AlGaN/GaN high-electron-mobility transistor with the vertical structure is improved.
Example 3:
fig. 1 is a schematic diagram of a vertical AlGaN/GaN high electron mobility transistor structure according to the present invention, which sequentially includes, from bottom to top: the semiconductor device comprises a drain electrode 101, a substrate 102, a bonding metal layer 103, a drain ohmic contact metal layer 104, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlGaN barrier layer 109, a P-type layer 110, a passivation layer 111, a source electrode 112 and a gate electrode 113, and is characterized in that: a vertical conductive channel 114 is arranged in the high resistance layer right below the gate electrode 113, so that the drain ohmic contact metal layer 104 is communicated with the GaN channel layer 107; as shown in fig. 29, the dislocation regulating structure includes an inverted hexagonal pyramid-shaped pit forming layer 401, a potential barrier regulating layer 402, and an inverted hexagonal pyramid-shaped pit merging layer 403, the inverted hexagonal pyramid-shaped pit forming layer 401 forms an inverted hexagonal pyramid-shaped pit 140 at the dislocation line 130, the potential barrier regulating layer 402 forms a relatively high resistance at the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the bottom of the inverted hexagonal pyramid-shaped pit 140 compared to the region outside the inverted hexagonal pyramid-shaped pit 140, and the inverted hexagonal pyramid-shaped pit merging layer 403 fills the inverted hexagonal pyramid-shaped pit.
The barrier control layer has a thickness h at the side wall of the inverted hexagonal pyramid-shaped pit 140pAl of (2)xGa1-xN, the thickness h is in the region outside the inverted hexagonal pyramid-shaped pit 140cAl of (2)xGa1-xN, wherein x is more than or equal to 0 and less than or equal to 1, and hc/hpNot less than 2, the thickness difference is used to make the area near the dislocation line in the inverted hexagonal conical pit 140 become relatively high resistance, thereby making the AlGaN/Ga in the vertical structureWhen the N high electron mobility transistor device bears high voltage, leakage current does not pass through a large amount of dislocation lines, but is uniformly distributed in the whole device section, and the breakdown voltage of the AlGaN/GaN high electron mobility transistor with the vertical structure is improved.
The vertical conductive channel 114 is formed by a through hole in the high resistance layer and a metal layer filled in the through hole, and the metal layer filled in the through hole may be the drain ohmic contact metal layer 104 or a separately deposited metal layer.
The vertical conductive via 114 may also be an n-type low resistance region formed within the high resistance layer using Si ion implantation.
The outer edge of the through hole in the high-resistance layer is smaller than the outer edge of the gate electrode, and the distance between the outer edge of the through hole in the high-resistance layer and the outer edge of the gate electrode is defined as Lg，1μm≤LgLess than or equal to 10 mu m. Preferably, LgThe difference with the thickness of the high-resistance layer is less than 1 micron.
An AlN insert layer 108 is arranged between the GaN channel layer 107 and the AlGaN barrier layer 109, the AlN insert layer has a thickness of 0-5 nm, and when the AlN insert layer has a thickness of 0nm, the AlN insert layer is removed.
The high-resistance layer 105 is GaN or AlGaN doped with C or Fe, and the thickness of the high-resistance layer is 1-10 μm.
The P-type layer 110 is P-GaN or P-AlGaN doped with Mg element.
The substrate 102 is a material with good electrical and thermal conductivity, such as Si, Ge, Cu alloy, etc., but not limited thereto.
The GaN channel layer 107 is an unintentionally doped GaN layer and has a thickness of 100nm to 500 nm.
The AlGaN barrier layer 109 is AlxGa(1-x)The thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
A manufacturing method of a vertical structure AlGaN/GaN high electron mobility transistor comprises the following steps:
(1) as shown in fig. 2, a substrate 115 is provided, and a HEMT epitaxial thin film 100 including a buffer layer 116, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlN layer 108, an AlGaN barrier layer 109, and a P-type layer 110 is grown on the substrate in sequence;
(2) as shown in fig. 3, the P-type layer outside the region where the gate electrode 113 is to be formed is etched away from the HEMT epitaxial film 100 by a photolithography and etching technique;
(3) as shown in fig. 4, a passivation layer 111 is grown on the AlGaN barrier layer 109 and the P-type layer 110;
(4) As shown in fig. 5, the passivation layer 111 at the position where the source electrode 112 is to be formed is etched by using a photolithography and etching technique, and then the source electrode 112 is formed by using a lift-off technique;
(5) as shown in fig. 6, the passivation layer 111 above the P-type layer 110 is etched away by using a photolithography and etching technique, and then the gate electrode 113 is formed by using a lift-off technique;
(6) as shown in fig. 7, an adhesive layer 117 is formed on the surface of the HEMT epitaxial thin film on which the source electrode 112 and the gate electrode 113 are formed;
(7) as shown in fig. 8, providing a transition substrate 118, forming an adhesive layer 117 on a front surface of the transition substrate 118, and forming a protective layer 119 on a back surface of the transition substrate 118;
(8) as shown in fig. 9, the HEMT epitaxial thin film 100 on which the source electrode 112 and the gate electrode 113 are fabricated is bonded to the transition substrate 118 by using the adhesive layer 117, the substrate 115 and the buffer layer 116 are etched away to obtain the transition HEMT epitaxial thin film 120, and the protective layer 119 on the reverse side of the transition substrate 118 can ensure that the transition substrate 118 is not etched in the process of etching the substrate 115 and the buffer layer 116;
(9) as shown in fig. 10, vertical conductive vias 114 are formed in the high-resistance layer 105;
(10) as shown in fig. 11, a drain ohmic contact layer 104, a bonding metal layer 103 are sequentially deposited on the transition HEMT epitaxial thin film 120 on which the vertical conductive channel 114 is formed;
(11) As shown in fig. 12, a substrate 102 is provided, a bonding metal layer 103 is deposited on the front surface of the substrate 102, a drain electrode 101 metal layer is deposited on the back surface, and the transition HEMT epitaxial film 120 and the substrate 102 are bonded together by the bonding metal layer 103;
(12) as shown in fig. 13, the protective layer 119, the transition substrate 118, and the adhesive layer 117 are removed, and a vertical structure AlGaN/GaN high electron mobility transistor is obtained.
The dislocation regulation structure can be realized by regulating the appearance near the dislocation, and the growth method comprises the following steps:
(1) as shown in fig. 27, an inverted hexagonal pyramidal pit-forming layer 401 is grown to form inverted hexagonal pyramidal pits 140 at the dislocation lines 130;
(2) growing undoped AlxGa1-xN layer as barrier regulating layer 402, inverted hexagonal pyramidal pit 140 sidewall AlxGa1-xN has a thickness of hpThe region Al outside the inverted hexagonal pyramid-shaped pit 140xGa1-xN has a thickness of hc，0≤x≤1，hp/hc≥2；
(3) Growing a merged layer 403 of inverted hexagonal pyramidal pits to fill up the inverted hexagonal pyramidal pits 140;
through the steps (1) to (3), Al is obtained on the side wall of the inverted hexagonal pyramid-shaped pit 140 as shown in FIG. 29xGa1-xAl outside the N-thick inverted hexagonal pyramid-shaped pit 140xGa1-xThe N thin barrier control layer 402 forms a relatively high resistance at the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the bottom of the inverted hexagonal pyramid-shaped pit 140 compared to the region outside the inverted hexagonal pyramid-shaped pit, and the relative resistance between the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the region outside the inverted hexagonal pyramid-shaped pit 140 can be controlled by adjusting the thickness ratio between the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the region outside the inverted hexagonal pyramid-shaped pit 140.
The method for forming the vertical conductive channel 114 in the high resistance layer 105 includes: a via hole is etched in the high-resistance layer 105, and metal is filled in the via hole, or the via hole may be filled when the drain ohmic contact layer 104 and the bonding metal layer 103 are deposited.
The method of forming the vertical conductive via 114 in the high resistance layer 105 further includes: an n-type low resistance region is formed by Si ion implantation in the high resistance layer 105.
The substrate 115 is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate.
The adhesive layer 117 may be a thermosetting adhesive, a hot-melt adhesive, a photo-curable organic adhesive, paraffin, or a low-melting metal.
In this embodiment, as shown in fig. 1, in the vertical AlGaN/GaN high electron mobility transistor, the dislocation regulation structure adopts a method for regulating the morphology, so that the barrier regulation layer is made of Al with a thicker thickness on the sidewall of the inverted hexagonal conical pitxGa1-xN, and the outer region of the inverted hexagonal pyramid-shaped pit is made of Al with a small thicknessxGa1-xN, by using AlxGa1-xThe N thickness difference enables the area near the dislocation line in the inverted hexagonal cone-shaped pit to be relatively high-resistance, so that leakage current of the vertical structure AlGaN/GaN high electron mobility transistor device is not greatly passed through the dislocation line but is uniformly distributed in the cross section of the whole device under the state of bearing high voltage, and the breakdown voltage of the vertical structure AlGaN/GaN high electron mobility transistor is improved.
Example 4:
fig. 1 is a schematic diagram of a vertical AlGaN/GaN high electron mobility transistor structure according to the present invention, which sequentially includes, from bottom to top: the semiconductor device comprises a drain electrode 101, a substrate 102, a bonding metal layer 103, a drain ohmic contact metal layer 104, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlGaN barrier layer 109, a P-type layer 110, a passivation layer 111, a source electrode 112 and a gate electrode 113, and is characterized in that: a vertical conductive channel 114 is arranged in the high resistance layer 105 right below the gate electrode 113, so that the drain ohmic contact metal layer 104 is communicated with the GaN channel layer 107; as shown in fig. 31, the dislocation regulating structure includes an inverted hexagonal pyramid-shaped pit forming layer 501, a potential barrier regulating layer 502, the inverted hexagonal pyramid-shaped pit forming layer 501 forms an inverted hexagonal pyramid-shaped pit 140 at a dislocation line 130, the potential barrier regulating layer 502 forms a relatively high resistance at the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the bottom of the inverted hexagonal pyramid-shaped pit 140 compared to the region outside the inverted hexagonal pyramid-shaped pit 140, and the potential barrier regulating layer 502 fills the inverted hexagonal pyramid-shaped pit.
The barrier regulation and control layer has a thickness h at the side wall of the inverted hexagonal cone-shaped pitpAl of (2)xGa1-xN, the thickness of the region outside the inverted hexagonal pyramid-shaped pit is h cAl of (2)xGa1-xN, wherein x is more than or equal to 0 and less than or equal to 1, and hc/hpNot less than 2, the thickness difference is used to make the area near the dislocation line in the inverted hexagonal conical pit phaseAnd for high resistance, the leakage current of the vertical AlGaN/GaN high electron mobility transistor device is not greatly passed through the dislocation line but is uniformly distributed in the cross section of the whole device under the state of bearing high voltage, so that the breakdown voltage of the vertical AlGaN/GaN high electron mobility transistor is improved.
The vertical conductive channel 114 is formed by a through hole in the high resistance layer 105 and a metal layer filled in the through hole, and the metal layer filled in the through hole may be the drain ohmic contact metal layer 104 or a separately deposited metal layer.
The vertical conductive via 114 may also be an n-type low resistance region formed within the high resistance layer 105 using Si ion implantation.
The outer edge of the through hole in the high resistance layer 105 is smaller than the outer edge of the gate electrode 113, and the distance between the outer edge of the through hole in the high resistance layer 105 and the outer edge of the gate electrode 113 is defined as Lg，1μm≤LgLess than or equal to 10 mu m. Preferably, LgThe difference from the thickness of the high resistance layer 105 is less than 1 micron.
An AlN insert layer 108 is provided between the GaN channel layer 107 and the AlGaN barrier layer 109, the AlN insert layer 108 has a thickness of 0 to 5nm, and when the AlN insert layer 108 has a thickness of 0nm, the AlN insert layer 108 is removed.
The high-resistance layer 105 is GaN or AlGaN doped with C or Fe elements, and the thickness of the high-resistance layer 105 is 1-10 μm.
The P-type layer 110 is P-GaN or P-AlGaN doped with Mg element.
The substrate 102 is a material with good electrical and thermal conductivity, such as Si, Ge, Cu alloy, etc., but not limited thereto.
The GaN channel layer 107 is an unintentionally doped GaN layer and has a thickness of 100nm to 500 nm.
The AlGaN barrier layer 109 is AlxGa(1-x)The thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
A manufacturing method of a vertical structure AlGaN/GaN high electron mobility transistor comprises the following steps:
(1) as shown in fig. 2, a substrate 115 is provided, and a HEMT epitaxial thin film 100 including a buffer layer 116, a high-resistance layer 105, a dislocation regulation structure 106, a GaN channel layer 107, an AlN layer 108, an AlGaN barrier layer 109, and a P-type layer 110 is grown on the substrate in sequence;
(2) as shown in fig. 3, the P-type layer outside the region where the gate electrode 113 is to be formed is etched away from the HEMT epitaxial film 100 by a photolithography and etching technique;
(3) as shown in fig. 4, a passivation layer 111 is grown on the AlGaN barrier layer 109 and the P-type layer 110;
(4) as shown in fig. 5, the passivation layer 111 at the position where the source electrode 112 is to be formed is etched by using a photolithography and etching technique, and then the source electrode 113 is formed by using a lift-off technique;
(5) As shown in fig. 6, the passivation layer 111 above the P-type layer 110 is etched away by using a photolithography and etching technique, and then the gate electrode 113 is formed by using a lift-off technique;
(6) as shown in fig. 7, an adhesive layer 117 is formed on the surface of the HEMT epitaxial thin film 100 on which the source electrode 112 and the gate electrode 113 are formed;
(7) as shown in fig. 8, providing a transition substrate 118, forming an adhesive layer 117 on a front surface of the transition substrate 118, and forming a protective layer 119 on a back surface of the transition substrate 118;
(8) as shown in fig. 9, the HEMT epitaxial thin film 100 on which the source electrode 112 and the gate electrode 113 are fabricated is bonded to the transition substrate 118 by using the adhesive layer 117, the substrate 115 and the buffer layer 116 are etched away to obtain the transition HEMT epitaxial thin film 120, and the protective layer 119 on the reverse side of the transition substrate 118 can ensure that the transition substrate 118 is not etched in the process of etching the substrate 115 and the buffer layer 116;
(9) as shown in fig. 10, vertical conductive vias 114 are formed in the high-resistance layer 105;
(10) as shown in fig. 11, a drain ohmic contact layer 104, a bonding metal layer 103 are sequentially deposited on the transition HEMT epitaxial thin film 120 on which the vertical conductive channel 114 is formed;
(11) as shown in fig. 12, a substrate 102 is provided, a bonding metal layer 103 is deposited on the front surface of the substrate 102, a drain electrode 101 metal layer is deposited on the back surface, and the transition HEMT epitaxial film 120 and the substrate 102 are bonded together by the bonding metal layer 103;
(12) As shown in fig. 13, the protective layer 119, the transition substrate 118, and the adhesive layer 117 are removed, and a vertical structure AlGaN/GaN high electron mobility transistor is obtained.
The dislocation regulation structure can be realized by regulating the appearance near the dislocation, and the growth method comprises the following steps:
(1) as shown in fig. 30, an inverted hexagonal pyramidal pit-forming layer 501 is grown to form inverted hexagonal pyramidal pits 140 at the dislocation lines 130;
(2) growing undoped AlxGa1-xN layer as barrier regulating layer 502 and inverted hexagonal pyramidal pit side wall AlxGa1-xN has a thickness of hpOuter region Al of inverted hexagonal pyramidal pitxGa1-xN has a thickness of hc，0≤x≤1，hp/hcThe potential barrier regulation layer 502 fills and levels the inverted hexagonal pyramidal pits 140 to serve as a combined layer of the regrown inverted hexagonal pyramidal pits;
through the steps (1) and (2), Al on the side wall of the inverted hexagonal pyramid-shaped pit 140 as shown in FIG. 31 is obtainedxGa1-xAl outside the N-thick inverted hexagonal pyramid-shaped pit 140xGa1-xThe N thin barrier control layer 502 forms a relatively high resistance at the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the bottom of the inverted hexagonal pyramid-shaped pit 140 compared to the region outside the inverted hexagonal pyramid-shaped pit 140, and the relative resistance between the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the region outside the inverted hexagonal pyramid-shaped pit 140 can be controlled by adjusting the thickness ratio between the sidewall of the inverted hexagonal pyramid-shaped pit 140 and the region outside the inverted hexagonal pyramid-shaped pit 140.
The method for forming the vertical conductive channel 114 in the high resistance layer 105 includes: and etching a through hole in the high-resistance layer, filling metal in the through hole, and filling the through hole when the drain electrode ohmic contact layer 104 and the bonding metal layer 103 are deposited.
The method of forming the vertical conductive via 114 in the high resistance layer 105 further includes: and an n-type low resistance region formed by Si ion implantation in the high resistance layer.
The substrate 115 is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate, or an aluminum nitride substrate.
The adhesive layer 117 may be a thermosetting adhesive, a hot-melt adhesive, a photo-curable organic adhesive, paraffin, or a low-melting metal.
In this embodiment, as shown in fig. 1, in the vertical AlGaN/GaN high electron mobility transistor, the dislocation regulation structure adopts a method for regulating the morphology, so that the barrier regulation layer is made of Al with a thicker thickness on the sidewall of the inverted hexagonal conical pitxGa1-xN, and the outer region of the inverted hexagonal pyramid-shaped pit is made of Al with a small thicknessxGa1-xN, by using AlxGa1-xThe N thickness difference enables the area near the dislocation line in the inverted hexagonal cone-shaped pit to be relatively high-resistance, so that leakage current of the vertical structure AlGaN/GaN high electron mobility transistor device is not greatly passed through the dislocation line but is uniformly distributed in the cross section of the whole device under the state of bearing high voltage, and the breakdown voltage of the vertical structure AlGaN/GaN high electron mobility transistor is improved.
The foregoing examples are merely illustrative of the preferred embodiments of the present invention, and the description is specific and detailed, but not to be construed as limiting the scope of the invention. It should be noted that, for those skilled in the art, various changes, modifications and substitutions can be made without departing from the spirit of the present invention, and these are all within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims (12)

1. A vertical structure AlGaN/GaN high electron mobility transistor structure sequentially comprises from bottom to top: drain electrode, base plate, bonding metal layer, drain electrode ohmic contact metal layer, high resistance layer, dislocation regulation and control structure, GaN channel layer, AlGaN barrier layer, P type layer, passivation layer, source electrode and grid electrode, its characterized in that: be equipped with perpendicular electrically conductive passageway in the high resistant layer under the grid electrode, make drain electrode ohmic contact metal level and GaN channel layer UNICOM, dislocation regulation and control structure includes that inverted hexagonal taper hole formative layer, potential barrier regulation and control layer and inverted hexagonal taper hole merge the layer, inverted hexagonal taper hole formative layer forms inverted hexagonal taper hole in dislocation line department, potential barrier regulation and control layer forms the relative high resistance than region outside inverted hexagonal taper hole at inverted hexagonal taper hole lateral wall and inverted hexagonal taper hole awl bottom position, inverted hexagonal taper hole merges the layer will inverted hexagonal taper hole is filled and is leveled.
2. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: the vertical conductive channel is composed of a through hole in the high-resistance layer and a metal layer filled in the through hole, and the metal layer filled in the through hole is a drain ohmic contact metal layer or a metal layer deposited independently; or the vertical conductive channel is an n-type low-resistance region formed by Si ion implantation in the high-resistance layer.
3. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: the barrier regulation layer is not doped with Al on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pitxGa1-xN, Si-doped Al outside the reverse hexagonal pyramid-shaped pitsxGa1-xN, wherein x is more than or equal to 0 and less than or equal to 0.3, and the area near the dislocation line in the inverted hexagonal conical pit becomes relatively high resistance by utilizing the Si doping difference; or the barrier regulating layer is arranged on the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit and is made of Al with the average Al component xxGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, wherein x is more than or equal to 0.4 and less than or equal to 1 and 0<y is less than or equal to 0.3, and x/y is greater than or equal to 1.5, and the area near the dislocation line in the inverted hexagonal conical pit becomes relatively high resistance by utilizing the Al component difference; or the barrier regulation and control layer has a thickness h at the side wall position of the inverted hexagonal cone-shaped pit pAl of (2)xGa1- xN, the thickness of the region outside the inverted hexagonal pyramid-shaped pit is hcAl of (2)xGa1-xN, wherein x is more than or equal to 0 and less than or equal to 1, and hp/hcNot less than 2, the area near the dislocation line in the inverted hexagonal conical pit becomes relatively high resistance by utilizing the thickness difference; or the barrier regulating layer is the combination of more than two of the three barrier regulating layers, namely more than two of Si doping difference, Al component difference and thickness difference are utilized to enable the area near the dislocation line in the inverted hexagonal cone-shaped pit to become relatively high resistance.
4. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: the outer edge of the vertical conductive channel is smaller than the outer edge of the gate electrode, defining a distance L between the outer edge of the vertical conductive channel and the outer edge of the gate electrodeg，1μm≤Lg≤10μm。
5. The structure of claim 4, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: l isgThe difference with the thickness of the high-resistance layer is less than 1 micron.
6. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: an AlN insert layer is arranged between the GaN channel layer and the AlGaN barrier layer, the thickness of the AlN insert layer is 0-5 nm, and when the thickness of the AlN doped layer is 0nm, the AlN insert layer is removed; the high-resistance layer is GaN or AlGaN doped with C or Fe, and the thickness of the high-resistance layer is 1-10 mu m; the P-type layer is P-GaN or P-AlGaN doped with Mg; the substrate is made of a material with good electric and heat conduction.
7. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: the substrate is Si, Ge, Cu or Cu alloy, but is not limited thereto.
8. The structure of claim 1, wherein the structure of the vertical AlGaN/GaN high electron mobility transistor is characterized in that: the GaN channel layer is an unintentionally doped GaN layer with a thickness of 100 nm-500 nm, and the AlGaN barrier layer is AlxGa(1-x)The thickness of the N layer is 10 nm-30 nm, wherein x is more than or equal to 0.1 and less than or equal to 0.5.
9. The method of fabricating a vertical structure AlGaN/GaN high electron mobility transistor structure according to any one of claims 1 to 8, comprising the steps of:
(1) providing a substrate, and sequentially growing an HEMT epitaxial film comprising a buffer layer, a high-resistance layer, a dislocation regulation structure, a GaN channel layer, an AlN insertion layer, an AlGaN barrier layer and a P-type layer on the substrate;
(2) etching off the P-type layer of the region outside the grid electrode to be manufactured on the HEMT epitaxial film by a photoetching technology;
(3) growing a passivation layer on the AlGaN barrier layer and the P-type layer;
(4) etching the passivation layer at the position where the source electrode needs to be manufactured by utilizing a photoetching technology, and manufacturing the source electrode by utilizing a stripping technology;
(5) Etching the passivation layer above the P-type layer by using a photoetching technology, and then manufacturing a grid electrode by using a stripping technology;
(6) manufacturing an adhesive layer on the surface of the HEMT epitaxial film with the source electrode and the grid electrode;
(7) providing a transition substrate, manufacturing a bonding layer on the front surface of the transition substrate, and manufacturing a protective layer on the back surface of the transition substrate;
(8) adhering the HEMT epitaxial film with the source electrode and the gate electrode and the transition substrate together by using the bonding layer, etching off the substrate and the buffer layer to obtain the transition HEMT epitaxial film, wherein in the process of etching the substrate and the buffer layer, the protective layer on the reverse side of the transition substrate can ensure that the transition substrate is not etched;
(9) forming a vertical conductive channel in the high-resistance layer;
(10) sequentially depositing a drain electrode ohmic contact layer and a bonding metal layer on the transition HEMT epitaxial film with the vertical conductive channel;
(11) providing a substrate, depositing a bonding metal layer on the front surface of the substrate, depositing a drain electrode metal layer on the back surface of the substrate, and binding the transition HEMT epitaxial film and the substrate together by using the bonding metal layer;
(12) and removing the protective layer, the transition substrate and the bonding layer to obtain the AlGaN/GaN high-electron-mobility transistor with the vertical structure.
10. The method of claim 9, wherein the AlGaN/GaN vertical structure transistor structure further comprises: the method for forming the vertical conductive channel in the high-resistance layer comprises the following steps: corroding a through hole in the high-resistance layer, and then filling metal in the through hole, or filling the through hole when depositing the drain ohmic contact layer and the bonding metal layer; or, the method for forming the vertical conductive channel in the high-resistance layer is an n-type low-resistance region formed by utilizing Si ion implantation in the high-resistance layer.
11. The method of claim 9, wherein the AlGaN/GaN vertical structure transistor structure further comprises: the dislocation regulation structure is realized by Si doping regulation near a dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing undoped AlxGa1-xN layer of Al on the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN thickness and Al outside the inverted hexagonal pyramid-shaped pitxGa1-xThe thickness ratio of N is 0.8-1, and x is more than or equal to 0 and less than or equal to 0.3;
(3) growing Si-doped AlxGa1-xN layer of Al on the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN thickness and Al outside the inverted hexagonal pyramid-shaped pitxGa1-xThe thickness ratio of N is 0.2-0.4, x is more than or equal to 0 and less than or equal to 0.3, and the concentration of doped Si is 1 multiplied by 10 18～1×1020cm-3；
(4) Decomposition of Si-doped AlxGa1-xN layer to make the decomposition rate of the side wall of the inverted hexagonal pyramid-shaped pit the same as that of the region outside the inverted hexagonal pyramid-shaped pit, and controlling the Si Al doping of the side wall of the inverted hexagonal pyramid-shaped pitxGa1-xN is completely decomposed to ensure that the side wall of the inverted hexagonal cone-shaped pit is doped with SiAlxGa1-xN is completely decomposed and can be properly over-decomposed to make Si-doped AlxGa1-xUndoped Al under NxGa1-xN is also partially decomposed and Si-doped Al is formed in the region outside the inverted hexagonal pyramidal pitsxGa1-xReserving an N layer;
(5) growing undoped AlxGa1-xN layers of reverse hexagonal conePit sidewall AlxGa1-xN thickness and Al outside the inverted hexagonal pyramid-shaped pitxGa1-xThe thickness ratio of N is 0.8-1, and x is more than or equal to 0 and less than or equal to 0.3;
(6) repeating the steps (3), (4) and (5) for multiple times to form a potential barrier regulation layer, wherein the repetition times are more than 2 times;
(7) growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
through the steps (1) to (7), a potential barrier regulation layer with the characteristic that the reverse hexagonal pyramid-shaped pits are not doped and Si is doped in the region outside the reverse hexagonal pyramid-shaped pits is obtained, and the potential barrier regulation layer, the reverse hexagonal pyramid-shaped pit forming layer and the reverse hexagonal pyramid-shaped pit merging layer form a dislocation regulation structure; the barrier control layer forms a relatively high resistance at the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit compared with the region outside the inverted hexagonal conical pit, and SiAl can be doped by adjusting xGa1-xThe relative resistance between the position of the inverted hexagonal conical pit and the region outside the inverted hexagonal conical pit is regulated and controlled by the Si doping concentration of the N layer;
or the dislocation regulation structure is realized by regulating and controlling Al components near the dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing an AlN layer to make the thickness of the side wall AlN of the inverted hexagonal conical pit equal to that of the AlN of the region outside the inverted hexagonal conical pit, wherein the thickness of the side wall AlN of the inverted hexagonal conical pit is 0.2-0.4 nm;
(3) growing a GaN layer, wherein the ratio of the thickness of GaN on the side wall of the inverted hexagonal conical pit to the thickness of GaN on the region outside the inverted hexagonal conical pit is 0.2-0.3, and the thickness of GaN on the side wall of the inverted hexagonal conical pit is 0.2-0.4 nm;
(4) repeating the steps (2) and (3) for multiple times to form a potential barrier regulation layer, wherein the repetition times are more than 2 times;
(5) growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
through the steps (1) to (5), the barrier control layer with high average Al component on the side wall of the inverted hexagonal conical pit and low average Al component in the region outside the inverted hexagonal conical pit is obtained, the barrier control layer is arranged on the side wall of the inverted hexagonal conical pit and the inverted hexagonalAl with average Al component x at the bottom of conical pit xGa1-xN, Al having an average Al composition y in the region outside the inverted hexagonal pyramid-shaped pitsyGa1-yN, wherein x is more than or equal to 0.4 and less than or equal to 1 and 0<y is less than or equal to 0.3, and x/y is more than or equal to 1.5; regulating the thickness of the AlN layer and the GaN layer on the side wall of the inverted hexagonal conical pit and the thickness of the area outside the inverted hexagonal conical pit to regulate the difference between the average Al component of the side wall of the inverted hexagonal conical pit and the average Al component of the area outside the inverted hexagonal conical pit, thereby regulating the relative resistance value between the position of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit;
or the dislocation regulation structure can be realized by regulating the appearance near the dislocation line, and the growth method comprises the following steps:
(1) growing a forming layer of inverted hexagonal cone-shaped pits, and forming inverted hexagonal cone-shaped pits at the dislocation lines;
(2) growing undoped AlxGa1-xThe N layer is used as a barrier regulation layer and is an inverted hexagonal conical pit side wall AlxGa1-xN has a thickness of hpOuter region Al of inverted hexagonal pyramidal pitxGa1-xN has a thickness of hc，0≤x≤1，hp/hc≥2；
(3) Growing a combined layer of the inverted hexagonal conical pits to fill and level the inverted hexagonal conical pits;
through the steps (1) to (3), Al with inverted hexagonal cone-shaped pit side wall is obtainedxGa1-xOuter region Al of N-thick inverted hexagonal conical pitxGa1-xThe N potential barrier regulation layer with the thin thickness characteristic forms a dislocation regulation structure together with the inverted hexagonal cone-shaped pit forming layer and the inverted hexagonal cone-shaped pit merging layer; forming a relatively high resistance in the side wall of the inverted hexagonal conical pit and the conical bottom of the inverted hexagonal conical pit compared with the area outside the inverted hexagonal conical pit, and regulating and controlling the relative resistance of the position of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit by regulating the thickness ratio of the side wall of the inverted hexagonal conical pit and the area outside the inverted hexagonal conical pit;
Or the dislocation regulation structure can also be realized by the combined regulation of two or three of Si doping, Al components and shapes near the dislocation line.
12. The method of claim 9, wherein the AlGaN/GaN vertical structure transistor structure further comprises: the substrate is a silicon substrate, a sapphire substrate, a silicon carbide substrate, a gallium nitride substrate or an aluminum nitride substrate; the bonding layer is thermosetting adhesive, hot-melt adhesive, light-cured organic adhesive, paraffin or low-melting-point metal.
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