CN116364534A - Preparation method of GaN-based device ohmic contact - Google Patents

Preparation method of GaN-based device ohmic contact Download PDF

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CN116364534A
CN116364534A CN202111627763.5A CN202111627763A CN116364534A CN 116364534 A CN116364534 A CN 116364534A CN 202111627763 A CN202111627763 A CN 202111627763A CN 116364534 A CN116364534 A CN 116364534A
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ohmic contact
gan
metal
layer
dry etching
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何元浩
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China Resources Microelectronics Chongqing Ltd
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China Resources Microelectronics Chongqing Ltd
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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
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/401—Multistep manufacturing processes
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23F—NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLIC MATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASS C23 AND AT LEAST ONE PROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25
    • C23F1/00—Etching metallic material by chemical means
    • C23F1/02—Local etching
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
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    • C23F1/00—Etching metallic material by chemical means
    • C23F1/10—Etching compositions
    • C23F1/12—Gaseous compositions
    • 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
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/41—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions
    • H01L29/417—Electrodes ; Multistep manufacturing processes therefor characterised by their shape, relative sizes or dispositions carrying the current to be rectified, amplified or switched
    • H01L29/41725—Source or drain electrodes for field effect devices
    • 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
    • H01L29/40—Electrodes ; Multistep manufacturing processes therefor
    • H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
    • H01L29/45—Ohmic electrodes
    • H01L29/452—Ohmic electrodes on AIII-BV compounds
    • 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
    • H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
    • H01L29/66007—Multistep manufacturing processes
    • H01L29/66075—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials
    • H01L29/66227—Multistep manufacturing processes of devices having semiconductor bodies comprising group 14 or group 13/15 materials the devices being controllable only by the electric current supplied or the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched, e.g. three-terminal devices
    • 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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    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

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Abstract

The invention provides a preparation method of GaN-based device ohmic contact, which comprises the following steps: forming a GaN-based epitaxial structure on the substrate; forming an insulating layer on the GaN-based epitaxial structure, and patterning; depositing a metal layer on the insulating layer; forming a photoresist layer on the metal layer and patterning; removing the metal layer which is not blocked by the photoresist layer by adopting a dry etching process, and forming the rest metal layer into ohmic contact metal; removing the photoresist layer; and (3) adopting low-power dry etching to treat the metal surface and removing the preset thickness of the ohmic contact metal, wherein the adopted parameters are as follows: chlorine-containing gas is adopted; the bias power is between 0W and 25W, excluding 0W; the source power is between 400W and 750W; and carrying out an annealing process on the ohmic contact metal to form ohmic contact. The low-power dry etching is adopted to treat the surface of the ohmic contact metal after the ohmic contact metal is formed by dry etching, so that the purity of the ohmic contact metal is effectively improved, and the electrical property of the formed ohmic contact is further improved after annealing.

Description

Preparation method of GaN-based device ohmic contact
Technical Field
The invention relates to the technical field of GaN-based electronic device preparation, in particular to a preparation method of GaN-based device ohmic contact.
Background
The third generation semiconductor material gallium nitride (GaN) is an ideal candidate material for high-voltage and high-frequency application because of the wider forbidden bandwidth and higher electron saturation velocity. Gallium nitride semiconductors are capable of withstanding stronger currents and higher voltages than silicon semiconductors, can achieve higher power densities, and thus exhibit sufficient market potential on radar, fast charge, and DC-DC transducers, and will be a new generation of consumer power electronics with cost competitiveness.
In the manufacturing process of the GaN power electronic device, a dry etching process for carrying out bombardment etching on the material by utilizing plasma gas atoms is one of the main processes in the manufacturing process of the GaN power electronic device, and the dry etching process has the characteristics of high selectivity, good etching anisotropy and the like, and has more controllability compared with wet etching. However, the dry etching process also causes additional problems in the manufacture of GaN power electronic devices, such as damage to the material surface during etching and unintended introduction of impurity atoms during etching, which can lead to undesirable defects in the device, affecting device characteristics and presenting a number of reliability and failure risks. In GaN power electronic devices, the ohmic contact characteristics of the electrodes are critical to the electrical characteristics of the entire device, and the damage generated during the direct etching of GaN-based epitaxial layer materials is mainly considered by the factors affecting the ohmic contact characteristics, mainly by introducing a gas with a buffer effect such as C 2 H 4 Reducing ion physical bombardment effect, or plasma treatment such as N on GaN surface 2 The surface morphology and defects of GaN are improved by plasma and the like to improve the ohmic contact characteristics, but the ohmic contact characteristics formed by the method are still to be further improved.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a method for manufacturing an ohmic contact of a GaN-based device, which is used to solve the problems of the prior art that the ohmic contact characteristics of the GaN-based device need to be further improved.
To achieve the above and other related objects, the present invention provides a method for manufacturing an ohmic contact of a GaN-based device, the method comprising:
providing a substrate, and forming a GaN-based epitaxial structure on the substrate;
forming an insulating layer on the GaN-based epitaxial structure, and patterning the insulating layer to form an opening on the insulating layer;
depositing a metal layer on the insulating layer, wherein the opening is filled with the metal layer;
forming a photoresist layer on the metal layer, and patterning to expose the metal layer above the opening;
removing the metal layer which is not shielded by the photoresist layer by adopting a dry etching process, and forming the rest metal layer into ohmic contact metal;
removing the photoresist layer;
and adopting low-power dry etching to treat the metal surface, and removing the preset thickness of the ohmic contact metal, wherein the parameters adopted by the low-power dry etching to treat the metal surface are as follows: chlorine-containing gas is adopted; the bias power is between 0W and 25W, excluding 0W; the source power is between 400W and 750W;
and carrying out an annealing process on the ohmic contact metal to form ohmic contact.
Optionally, the low-power dry etching is adopted to treat the metal surface, and the method further comprises the following steps of: and a step of adopting a plasma metal surface treatment process to treat the ohmic contact metal, wherein the parameters adopted by the plasma metal surface treatment process are as follows: bias power is 0W; the source power is between 1200W and 1500W.
Further, the gas adopted in the process of treating the metal surface by the plasma is N 2 Or H 2 。
Alternatively, the plasma treatment metal surface process is implemented using an ICP apparatus or an ICP-RIE apparatus.
Optionally, the chlorine-containing gas in the metal surface treated by the low-power dry etching is Cl 2 BCl (binary coded decimal) of the same 3 At least one of them.
Optionally, the low-power dry etching is adopted to treat the metal surface, and the preset thickness for removing the ohmic contact metal is between 10nm and 40 nm.
Alternatively, the low-power dry etching treatment of the metal surface is realized by an ICP device or an ICP-RIE device.
Optionally, the parameters used for removing the metal layer which is not blocked by the photoresist layer by adopting a dry etching process are as follows: chlorine-containing gas is adopted; the bias power is between 80W and 200W; the source power is between 800W and 1400W.
Optionally, the material of the insulating layer is silicon nitride or silicon oxide.
Optionally, the GaN-based device is a GaN-based HEMT device, the GaN-based epitaxial structure includes a GaN channel layer and an AlGaN barrier layer, and the ohmic contact formed includes a source ohmic contact and a drain ohmic contact.
As described above, the preparation method of the GaN-based device ohmic contact of the invention adopts low-power dry etching to treat the metal surface of the ohmic contact metal after the ohmic contact metal is formed by dry etching, adopts low bias power between 0W and 25W to reduce the bombardment rate of the etched surface, adopts lower source power between 400W and 750W to reduce the plasma activation reaction, thereby slowly and low-damage removing the metal surface, and leading a layer of high-concentration impurity atoms, such as Cl atoms, introduced by the metal dry etching process to be etched away along with the metal surface layer, thereby removing the high-concentration impurity atoms, reducing the continuous introduction of new damage, effectively improving the purity of the ohmic contact metal and further improving the electrical property of the formed ohmic contact after annealing.
Drawings
Fig. 1 shows a process flow diagram of a method for fabricating an ohmic contact to a GaN-based device of the invention.
Fig. 2 to 10 are schematic cross-sectional structures of the steps in the method for fabricating an ohmic contact of a GaN-based device according to an example of the invention.
Description of element reference numerals
100 GaN-based epitaxial structure
101 GaN channel layer
102 AlGaN barrier layer
103. Insulating layer
104. An opening
105. Metal layer
106. Photoresist layer
107. Ohmic contact metal
108. Impurity atoms
S1 to S8 steps
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention.
Please refer to fig. 1 to 10. It should be noted that, the illustrations provided in the present embodiment merely illustrate the basic concept of the present invention by way of illustration, and only the components related to the present invention are shown in the drawings rather than the number, shape and size of the components in actual implementation, and the types, numbers and proportions of the components in actual implementation may be changed according to actual needs, and the layout of the components may be more complex.
As described in the background art, the factors affecting ohmic contact characteristics are mainly considered to be damage generated during the process of directly etching GaN-based epitaxial layer material by introducing a gas such as C having a buffer effect 2 H 4 Reducing ion physical bombardment effect, or plasma treatment such as N on GaN surface 2 The surface morphology and defects of GaN are improved by plasma and the like to improve the ohmic contact characteristics, but the ohmic contact characteristics formed by the method are still to be further improved. Based on this, the inventors have found through research that the general adoption of GaN-based devicesThe dry etching of metals to form patterned ohmic contact metals, the dry etching generally uses chlorine (Cl) -based gas as the main gas for opening electrode pattern windows and forming patterned metals, after ohmic contact is formed by etching, a large number of Cl atoms are observed in the ohmic contact metals and in GaN-based epitaxy, and peaks of Cl atom content appear on the ohmic contact metal surfaces, which the inventors analyze may be that the photoresist layer cannot effectively block the injection of Cl atoms during etching, and the dry etching step of patterned metals introduces a large number of Cl atoms on the metal surfaces, and further, the diffusion of Cl atoms from the metal surfaces into GaN-based epitaxy is aggravated during annealing, and Cl atoms entering into GaN-based epitaxy interact with defects in GaN-based epitaxy materials to form acceptor complexes, which eventually lead to the difficulty in forming ohmic contact between GaN-based epitaxy and metals, resulting in the electrical degradation of devices.
Based on the analysis, the invention provides a preparation method of the GaN-based device ohmic contact, which is used for effectively improving the electrical performance of the ohmic contact formed subsequently from the perspective of effectively reducing or even removing impurity atoms on the surface of the ohmic contact metal. As shown in fig. 1, the preparation method comprises the following steps:
providing a substrate, and forming a GaN-based epitaxial structure on the substrate;
forming an insulating layer on the GaN-based epitaxial structure, and patterning the insulating layer to form an opening on the insulating layer;
depositing a metal layer on the insulating layer, wherein the opening is filled with the metal layer;
forming a photoresist layer on the metal layer, and patterning to expose the metal layer above the opening;
removing the metal layer which is not shielded by the photoresist layer by adopting a dry etching process, and forming the rest metal layer into ohmic contact metal;
removing the photoresist layer;
and adopting low-power dry etching to treat the metal surface, and removing the preset thickness of the ohmic contact metal, wherein the parameters adopted by the low-power dry etching to treat the metal surface are as follows: chlorine-containing gas is adopted; the bias power is between 0W and 25W, excluding 0W; the source power is between 400W and 750W;
and carrying out an annealing process on the ohmic contact metal to form ohmic contact.
The dry etching process generally employs ICP equipment or ICP-RIE equipment, and the etching gas is chlorine-containing gas such as Cl 2 And/or BCl 3 After the dry etching parameter etching with the bias power between 80W and 200W and the source power between 800W and 1400W is adopted, the wafer SIMS analysis results show that Cl impurity atoms are introduced into the ohmic contact metal surface after the dry etching, and the TLM pattern on the wafer is electrically tested after annealing, so that the result shows that the ohmic contact characteristic on the wafer is poor.
According to the preparation method of the GaN-based device ohmic contact, after ohmic contact metal is formed by dry etching, the ohmic contact metal is subjected to low-power dry etching to treat the metal surface, the low bias power is adopted to be between 0W and 25W so as to reduce the bombardment rate of the etched surface, the lower source power is adopted to be between 400W and 750W so as to reduce the plasma activation reaction, and therefore the metal surface is removed slowly and with low damage, a layer of high-concentration impurity atoms, such as Cl atoms, introduced by the metal dry etching process are etched along with the metal surface layer, the high-concentration impurity atoms are removed, new damage is reduced to be introduced continuously, the purity of the ohmic contact metal is effectively improved, and the electrical property of the formed ohmic contact is improved after annealing.
The method for preparing the ohmic contact of the GaN-based device of the invention is described in detail below by taking the GaN-based HEMT device as an example, but the method is not limited thereto, and any method for preparing the ohmic contact of the GaN-based device can be suitable for the preparation method of the invention.
As shown in fig. 2, step S1 is first performed to provide a substrate, and a GaN-based epitaxial structure 100 is formed on the substrate, where the GaN-based epitaxial structure 100 includes a GaN channel layer 101 and an AlGaN barrier layer 102 from bottom to top.
As an example, the substrate may be any suitable semiconductor substrate, for example, the substrate may be a Si substrate, a SiC substrate, a gallium nitride substrate, a sapphire substrate, or the like.
As an example, the GaN channel layer 101 and AlGaN barrier layer 102 may be grown using epitaxial techniques.
As shown in fig. 2, step S2 is then performed to form an insulating layer 103 on the GaN-based epitaxial structure 100, and patterning is performed to form an opening 104 on the insulating layer 103. The openings 104 include openings for subsequent source ohmic contacts and openings for drain ohmic contacts.
As an example, the insulating layer 103 may be made of a conventional insulating material, such as silicon nitride, silicon oxide, or the like, and is selected as a silicon nitride insulating layer in this embodiment. The openings 104 are formed using a photolithographic, etching process.
As shown in fig. 3, step S3 is performed to deposit a metal layer 105 on the insulating layer 103, and the metal layer 105 fills the opening 104. The metal layer 105 may be deposited using conventional processes such as CVD deposition processes, or sputter deposition processes, among others.
As shown in fig. 4, step S4 is performed to form a photoresist layer 106 on the metal layer 105, and then patterning the photoresist layer to expose the metal layer 105 above the opening 104.
As shown in fig. 5 and 6, step S5 is performed, in which the metal layer 105 not covered by the photoresist layer 106 is removed by a dry etching process, and the remaining metal layer 105 is formed into an ohmic contact metal 107, and in the HEMT device structure, the ohmic contact metal 107 is a source ohmic contact metal and a drain ohmic contact metal, respectively. During this step, the inventors believe that the photoresist layer 106 does not effectively block atoms in the dry etching gas, causing it to be implanted through the photoresist layer 106 to the surface of the ohmic contact metal 107, thereby introducing a large number of impurity atoms 108 at its surface.
As an example, the dry etching process employs an ICP apparatus or an ICP-RIE apparatus, and the etching gas employed is a chlorine-containing gas such as Cl 2 And/or BCl 3 The bias power is between 80W and 200W; the source power is between 800W and 1400W, so that after dry etching, the ohmic contact is realizedAnd introducing Cl impurity atoms on the surface of the metal.
As shown in fig. 7, step S6 is performed to remove the photoresist layer 106.
As shown in fig. 8, step S7 is performed, and the metal surface is processed by low-power dry etching, to remove the preset thickness of the ohmic contact metal 107, where the parameters used for the low-power dry etching process are as follows: chlorine-containing gas is adopted; the bias power is between 0W and 25W, excluding 0W, including 25W; the source power is between 400W and 750W, inclusive.
As a preferred example, the predetermined thickness for removing the ohmic contact metal 107 is selected to be between 10nm and 40nm, so as to completely remove the ohmic contact metal containing impurity atoms. Chlorine-containing gases are generally selected from Cl 2 BCl (binary coded decimal) of the same 3 At least one of them.
As an example, the apparatus used for the low power dry etching treatment of the metal surface may be an ICP apparatus or an ICP-RIE apparatus.
As a preferred example, as shown in fig. 9, a further step may be applied after this step: and a step of treating the ohmic contact metal 107 by a plasma treatment metal surface process, wherein the parameters adopted by the plasma treatment metal surface process are as follows: bias power is 0W; the source power is between 1200W and 1500W. The high-energy plasma gas formed in the step can separate out the residual impurity atoms on the metal surface to further reduce the impurity atoms in ohmic contact with the metal surface; in addition, the high-energy plasma gas can repair the damage of the dry etching gas to the surface of the ohmic contact metal, so that the defect is reduced. The gas used in the step of plasma treating the ohmic contact metal 107 is N 2 Or H 2 . In addition, the step can also be realized by adopting ICP equipment or ICP-RIE equipment, so that the surface of the ohmic contact metal 107 and the surface of the ohmic contact metal 107 can be processed by adopting low-power dry etching in the same equipment, new process equipment is not needed, and the time of repeated vacuumizing is saved. Etching is performed as shown in fig. 10, and finally, step S8 is performed, the annealing process is performed on the ohmic contact metal 107,ohmic contacts are formed. In the HEMT device structure, the finally formed ohmic contacts comprise a source ohmic contact and a drain ohmic contact, so that the efficiency and the feasibility are high compared with other surface treatment technologies, and meanwhile, the cost is saved.
The annealing process in this step uses conventional process parameters for achieving metal ohmic contact, and is not so limited.
In summary, the invention provides a method for preparing an ohmic contact of a GaN-based device, which comprises the steps of forming an ohmic contact metal by dry etching, treating the metal surface of the ohmic contact metal by low-power dry etching, reducing the bombardment rate of the etched surface by low bias power between 0W and 25W, reducing the plasma activation reaction by low source power between 400W and 750W, so as to slowly and low-damage the metal surface, and removing a layer of high-concentration impurity atoms, such as Cl atoms, introduced by the metal dry etching process, along with the metal surface layer, thereby removing the high-concentration impurity atoms, reducing the continuous introduction of new damage, effectively improving the purity of the ohmic contact metal, and further improving the electrical property of the formed ohmic contact after annealing. Therefore, the invention effectively overcomes various defects in the prior art and has high industrial utilization value.
The above embodiments are merely illustrative of the principles of the present invention and its effectiveness, and are not intended to limit the invention. Modifications and variations may be made to the above-described embodiments by those skilled in the art without departing from the spirit and scope of the invention. Accordingly, it is intended that all equivalent modifications and variations of the invention be covered by the claims, which are within the ordinary skill of the art, be within the spirit and scope of the present disclosure.

Claims (10)

1. A method for preparing an ohmic contact of a GaN-based device, the method comprising:
providing a substrate, and forming a GaN-based epitaxial structure on the substrate;
forming an insulating layer on the GaN-based epitaxial structure, and patterning the insulating layer to form an opening on the insulating layer;
depositing a metal layer on the insulating layer, wherein the opening is filled with the metal layer;
forming a photoresist layer on the metal layer, and patterning to expose the metal layer above the opening;
removing the metal layer which is not shielded by the photoresist layer by adopting a dry etching process, and forming the rest metal layer into ohmic contact metal;
removing the photoresist layer;
and adopting low-power dry etching to treat the metal surface, and removing the preset thickness of the ohmic contact metal, wherein the parameters adopted by the low-power dry etching to treat the metal surface are as follows: chlorine-containing gas is adopted; the bias power is between 0W and 25W, excluding 0W; the source power is between 400W and 750W;
and carrying out an annealing process on the ohmic contact metal to form ohmic contact.
2. The method for manufacturing the ohmic contact of the GaN-based device according to claim 1, wherein the step of processing the metal surface by low power dry etching, and removing the ohmic contact metal further comprises: and a step of adopting a plasma metal surface treatment process to treat the ohmic contact metal, wherein the parameters adopted by the plasma metal surface treatment process are as follows: bias power is 0W; the source power is between 1200W and 1500W.
3. The method for manufacturing an ohmic contact of a GaN-based device according to claim 2, characterized by: the gas adopted in the process of treating the metal surface by the plasma is N 2 Or H 2 。
4. The method for manufacturing an ohmic contact of a GaN-based device according to claim 2, characterized by: the plasma treatment metal surface process is realized by adopting ICP equipment or ICP-RIE equipment.
5. According to claim 1The preparation method of the GaN-based device ohmic contact is characterized by comprising the following steps: the chlorine-containing gas in the metal surface treated by the low-power dry etching is Cl 2 BCl (binary coded decimal) of the same 3 At least one of them.
6. The method for manufacturing an ohmic contact of a GaN-based device according to claim 1, characterized by: and adopting the low-power dry etching to treat the metal surface, wherein the preset thickness for removing the ohmic contact metal is between 10nm and 40 nm.
7. The method for manufacturing an ohmic contact of a GaN-based device according to claim 1, characterized by: the low-power dry etching treatment of the metal surface is realized by adopting ICP equipment or ICP-RIE equipment.
8. The method for manufacturing an ohmic contact of a GaN-based device according to claim 1, characterized by: the parameters adopted for removing the metal layer which is not blocked by the photoresist layer by adopting a dry etching process are as follows: chlorine-containing gas is adopted; the bias power is between 80W and 200W; the source power is between 800W and 1400W.
9. The method for manufacturing an ohmic contact of a GaN-based device according to claim 1, characterized by: the insulating layer is made of silicon nitride or silicon oxide.
10. The method for manufacturing an ohmic contact of a GaN-based device according to claim 1, characterized by: the GaN-based device is a GaN-based HEMT device, the GaN-based epitaxial structure comprises a GaN channel layer and an AlGaN barrier layer, and the formed ohmic contact comprises a source ohmic contact and a drain ohmic contact.
CN202111627763.5A 2021-12-28 2021-12-28 Preparation method of GaN-based device ohmic contact Pending CN116364534A (en)

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