High electron mobility transistor chip and preparation method thereof
By employing a graded AlGaN interface and body layers with varying Al compositions, the lattice mismatch issue in HEMT chips is addressed, resulting in improved 2DEG scattering and reduced leakage current.
Patent Information
- Application Number
- CN202510445181.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-10
- Publication Date
- 2025-07-15
AI Technical Summary
Due to the mismatch between the lattice between the epitaxial layer and the substrate, the interface of the HEMT chip is prone to high-density dislocation, resulting in intensified two-dimensional electron gas scattering and increased device leakage.
A regeneration layer is provided on the side facing the substrate on the channel layer, including an AlGaN interface layer and an AlGaN main layer. The Al component gradually increases along the epitaxial growth direction. By adjusting the changes in the Al component to balance the stress and polarization effect, the high-quality growth of the regeneration layer is ensured.
Effectively reduce the density of interface defects, improve the growth quality of subsequent barrier layers and cap layers, reduce device leakage, and improve the mobility of two-dimensional electron gas.
Smart Images
Figure CN120321982A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure relates to the field of semiconductor technology, and particularly to a high electron mobility transistor chip and a method for manufacturing the same. Background Art
[0002] HEMT (High Electron Mobility Transistor) is a heterojunction field effect transistor, which is widely used in fields such as aerospace, communication technology, automotive electronics, and switching power supplies. In particular, it has received extensive attention in high-power and high-frequency application fields. The HEMT chip is the basis for manufacturing electronic power devices.
[0003] In the related art, the HEMT chip mainly includes a substrate and an epitaxial layer grown on the substrate. The epitaxial layer includes a channel layer, a barrier layer, and a cap layer grown in sequence.
[0004] However, due to the lattice mismatch between the epitaxial layer and the substrate, a high density of dislocations is likely to be generated at the interface, resulting in increased scattering of two-dimensional electron gas (2DEG) and increased device leakage. Summary of the Invention
[0005] Embodiments of the present disclosure provide a high electron mobility transistor chip and a method for manufacturing the same, which can effectively solve the problem of lattice mismatch. The technical solution is as follows:
[0006] On the one hand, embodiments of the present disclosure provide a high electron mobility transistor chip, including a substrate, and a channel layer, a regrowth layer, a barrier layer, and a cap layer sequentially stacked on one side of the substrate;
[0007] The regrowth layer includes an AlGaN interface layer and an AlGaN main layer stacked along the epitaxial growth direction. The Al component of the AlGaN interface layer is 10% - 15%, and the Al component of the AlGaN main layer is 20% - 30%.
[0008] In an implementation manner of the present disclosure, the AlGaN interface layer includes a plurality of sub-interface layers, and the sub-interface layers are sequentially stacked, and the Al component of each sub-interface layer gradually increases along the epitaxial growth direction.
[0009] In an implementation manner of the present disclosure, the AlGaN main layer includes a plurality of sub-main layers, and the sub-main layers are sequentially stacked, and the Al component of each sub-main layer gradually increases along the epitaxial growth direction.
[0010] In an implementation manner of the present disclosure, along the epitaxial growth direction, the Al component of the regrowth layer varies or changes abruptly within the range of 5% - 30%.
[0011] In one implementation of the present disclosure, the thickness of the regrowth layer is 10 - 50 nm.
[0012] On the other hand, an embodiment of the present disclosure provides a method for manufacturing a high electron mobility transistor chip. The manufacturing method is used to manufacture the high electron mobility transistor chip as described in the above aspect. The manufacturing method includes:
[0013] Providing a substrate;
[0014] Preparing a channel layer on one side of the substrate;
[0015] Sequentially preparing an AlGaN interface layer and an AlGaN main layer on the side of the channel layer facing away from the substrate, such that the Al component of the AlGaN interface layer is 10% - 15%, the Al component of the AlGaN main layer is 20% - 30%, and the AlGaN interface layer and the AlGaN main layer form a regrowth layer;
[0016] Sequentially preparing a barrier layer and a cap layer on the side of the regrowth layer facing away from the substrate.
[0017] In one implementation of the present disclosure, before sequentially preparing the AlGaN interface layer and the AlGaN main layer on the side of the channel layer facing away from the substrate, the manufacturing method includes:
[0018] Performing plasma pretreatment on the side of the channel layer facing away from the substrate;
[0019] Performing in-situ etching on the side of the channel layer facing away from the substrate, with an etching depth of 1 - 5 nm.
[0020] In one implementation of the present disclosure, performing plasma pretreatment on the side of the channel layer facing away from the substrate includes:
[0021] Placing it in a mixed atmosphere of H2 / N2, and bombarding the side of the channel layer facing away from the substrate with plasma having a radio frequency power of 50 - 200 W for a bombardment time of 30 - 120 s.
[0022] In one implementation of the present disclosure, sequentially preparing the AlGaN interface layer and the AlGaN main layer on the side of the channel layer facing away from the substrate includes:
[0023] Setting the growth temperature to 800 - 900 °C, setting the growth pressure to 50 - 300 torr, and growing the AlGaN interface layer;
[0024] Set the growth temperature to 1000 - 1050 °C and the growth pressure to 50 - 300 torr to grow the AlGaN main layer.
[0025] In one implementation of the present disclosure, growing the AlGaN interface layer includes:
[0026] Growing multiple sub-interface layers in sequence such that the Al composition of each sub-interface layer gradually increases along the epitaxial growth direction;
[0027] Growing the AlGaN main layer includes:
[0028] Growing multiple sub-main layers in sequence such that the Al composition of each sub-main layer gradually increases along the epitaxial growth direction.
[0029] The beneficial effects brought by the technical solutions provided by the embodiments of the present disclosure at least include:
[0030] In the high electron mobility transistor chip provided by the embodiments of the present disclosure, a regrowth layer is provided on the side of the channel layer facing away from the substrate. By ensuring the high-quality growth of the regrowth layer, the interface defect density can be effectively reduced, which is beneficial to the subsequent growth of the barrier layer and the capping layer.
[0031] The regrowth layer includes an AlGaN interface layer and an AlGaN main layer. The AlGaN interface layer and the AlGaN main layer are stacked along the epitaxial growth direction. The Al composition of the AlGaN interface layer is 10% - 15%, and the Al composition of the AlGaN main layer is 20% - 30%. Therefore, the overall Al composition of the regrowth layer gradually increases along the epitaxial growth direction. In this way, the stress and polarization effects can be balanced.
[0032] That is to say, by providing a regrowth layer on the side of the channel layer facing away from the substrate and utilizing the change in the Al composition in the regrowth layer, the high-quality growth of the regrowth layer is achieved, effectively balancing the stress and polarization effects, thereby further ensuring the growth quality of the subsequent barrier layer and capping layer. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present disclosure. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0034] Figure 1 is a schematic structural diagram of a high electron mobility transistor provided by an embodiment of the present disclosure;
[0035] Figure 2It is a schematic structural diagram of the regrown layer provided by an embodiment of the present disclosure;
[0036] Figure 3 It is a flowchart of a method for manufacturing a high electron mobility transistor chip provided by an embodiment of the present disclosure;
[0037] Figure 4 It is a flowchart of another method for manufacturing a high electron mobility transistor chip provided by an embodiment of the present disclosure.
[0038] Reference numerals in the accompanying drawings:
[0039] 10. Substrate;
[0040] 20. Channel layer;
[0041] 30. Regrown layer;
[0042] 310. AlGaN interface layer; 311. Sub-interface layer; 320. AlGaN main layer; 321. Sub-main layer;
[0043] 40. Barrier layer;
[0044] 50. Capping layer;
[0045] 60. Buffer layer. Detailed implementation manners
[0046] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following will further describe the embodiments of the present disclosure in detail with reference to the accompanying drawings.
[0047] As a representative of the third-generation semiconductor materials, GaN is an important semiconductor material that emerged after Si and GaAs materials. Due to its excellent properties such as a large bandgap width, a high critical field strength, a high carrier saturation velocity, and high temperature and radiation resistance, it has received extensive attention.
[0048] For a GaN-based high electron mobility transistor, a conductive channel is generated by forming a two-dimensional electron gas (2DEG) with a high concentration and a high mobility at the heterojunction, thereby realizing the conduction of the device. Due to its excellent properties such as a high thermal conductivity, a low on-resistance, and the ability to withstand high-frequency and high-voltage conditions, GaN-based high electron mobility transistors have become a research hotspot in the fields of high-frequency and high-power devices and switching devices in recent years.
[0049] In the related art, an HEMT chip mainly includes a substrate and an epitaxial layer grown on the substrate. The epitaxial layer includes a channel layer, a barrier layer, and a capping layer grown in sequence.
[0050] However, due to the lattice mismatch between the epitaxial layer and the substrate, a high density of dislocations is likely to occur at the interface, leading to increased scattering of the two-dimensional electron gas and increased leakage current of the device.
[0051] To solve the above technical problems, embodiments of the present disclosure provide a high electron mobility transistor. Figure 1 As a schematic structural diagram of the high electron mobility transistor, combined with Figure 1 , in this embodiment, the high electron mobility transistor includes a substrate 10, and a channel layer 20, a regrowth layer 30, a barrier layer 40, and a cap layer 50 that are sequentially stacked on one side of the substrate 10. The regrowth layer 30 includes an AlGaN interface layer 310 and an AlGaN main layer 320 stacked along the epitaxial growth direction. The Al component of the AlGaN interface layer 310 is 10% - 15%, and the Al component of the AlGaN main layer 320 is 20% - 30%.
[0052] The high electron mobility transistor chip provided by the embodiments of the present disclosure is provided with a regrowth layer 30 on the side of the channel layer 20 facing away from the substrate 10. By ensuring the high-quality growth of the regrowth layer 30, the interface defect density can be effectively reduced, which is beneficial to the subsequent growth of the barrier layer 40 and the cap layer 50.
[0053] The regrowth layer 30 includes an AlGaN interface layer 310 and an AlGaN main layer 320. The AlGaN interface layer 310 and the AlGaN main layer 320 are stacked along the epitaxial growth direction. The Al component of the AlGaN interface layer 310 is 10% - 15%, and the Al component of the AlGaN main layer 320 is 20% - 30%. Therefore, the overall Al component of the regrowth layer 30 gradually increases along the epitaxial growth direction. In this way, the stress and polarization effects can be balanced.
[0054] That is to say, by providing a regrowth layer 30 on the side of the channel layer 20 facing away from the substrate 10 and using the change in the Al component in the regrowth layer 30, the high-quality growth of the regrowth layer 30 can be achieved, effectively balancing the stress and polarization effects, thereby further ensuring the growth quality of the subsequent barrier layer 40 and cap layer 50.
[0055] In this embodiment, the thickness of the regrowth layer 30 is 10 - 50 nm.
[0056] In the above implementation, the thickness of the regrowth layer 30 is designed to be the above value. On the one hand, it can ensure that the functionality of the regrowth layer 30 will not be affected by too small a thickness, and on the other hand, it can also ensure that the preparation efficiency of the regrowth layer 30 will not be affected by too large a thickness.
[0057] Exemplarily, the thickness of the AlGaN interface layer 310 is 2 - 10 nm, the thickness of the AlGaN main layer 320 is 5 - 45 nm, and the thickness of the AlGaN interface layer 310 is not greater than that of the AlGaN main layer 320.
[0058] In the above implementation, the AlGaN interface layer 310 is mainly used to inhibit the decomposition of GaN in the channel layer 20 to reduce the number of interface holes, so it only needs to be set thinner, while the AlGaN main layer 320 is mainly used to improve the crystal quality and reduce the dislocation density, so it needs to be set thicker.
[0059] Figure 2 For the structural schematic diagram of the regrowth layer 30, combined with Figure 2 , in this embodiment, the AlGaN interface layer 310 includes a plurality of sub-interface layers 311, and the sub-interface layers 311 are stacked in sequence, and the Al component of each sub-interface layer 311 gradually increases along the epitaxial growth direction.
[0060] In the above implementation, the AlGaN interface layer 310 is composed of a plurality of stacked sub-interface layers 311, the stacking direction of each sub-interface layer 311 is the epitaxial growth direction, and the Al component of each sub-interface layer 311 increases in sequence, which can achieve the balance of stress and polarization effect of the AlGaN interface layer 310.
[0061] In this embodiment, the Al component of each sub-interface layer 311 increases linearly along the epitaxial growth direction.
[0062] For example, if the number of sub-interface layers 311 is 5, then the Al component of the sub-interface layer 311 closest to the substrate 10 is 10%, and along the epitaxial growth direction, the Al components of the other sub-interface layers 311 are 11%, 12%, 13%, 14%, and 15% respectively.
[0063] Continue to refer to Figure 2 , in this embodiment, the AlGaN main layer 320 includes a plurality of sub-main layers 321, and the sub-main layers 321 are stacked in sequence, and the Al component of each sub-main layer 321 gradually increases along the epitaxial growth direction.
[0064] In the above implementation, the AlGaN main layer 320 is composed of a plurality of stacked sub-main layers 321, the stacking direction of each sub-main layer 321 is the epitaxial growth direction, and the Al component of each sub-main layer 321 increases in sequence, which can achieve the balance of stress and polarization effect of the AlGaN main layer 320.
[0065] In this embodiment, the Al component of each sub-main layer 321 increases linearly along the epitaxial growth direction.
[0066] For example, if the number of the sub-main body layers 321 is 5 layers, then the Al component of one sub-main body layer 321 closest to the substrate 10 is 20%, and along the epitaxial growth direction, the Al components of the other sub-interface layers 311 are 22%, 24%, 26%, 28%, and 30% respectively.
[0067] As can be seen from the foregoing, the regrowth layer 30 can be formed by stacking a plurality of sub-interface layers 311 and a plurality of sub-main body layers 321. In this case, by adjusting the Al components of the respective sub-interface layers 311 and sub-main body layers 321, the overall Al component of the regrowth layer 30 can be made to gradually increase along the epitaxial growth direction.
[0068] In addition, the Al component of the regrowth layer 30 can also be changed by adjusting the flow rate of the Al source. In this case, along the epitaxial growth direction, the Al component of the regrowth layer 30 varies or mutates within the range of 5% to 30%.
[0069] In the above implementation manner, by adjusting the change of the Al component of the regrowth layer 30, the balanced stress and polarization effect of the growth layer can be achieved.
[0070] In this embodiment, the channel layer 20 is a GaN layer, the barrier layer 40 is an AlGaN layer, and the capping layer 50 is a p-type GaN layer.
[0071] In the above implementation manner, an AlGaN / GaN heterojunction is formed between the channel layer 20 and the barrier layer 40.
[0072] Figure 3 The flowchart of a preparation method of a high electron mobility transistor chip provided by an embodiment of the present disclosure is shown in Figure 3 , and the preparation method includes:
[0073] Step 301: Provide a substrate 10.
[0074] Step 302: Prepare a channel layer 20 on one side of the substrate 10.
[0075] Step 303: Sequentially prepare an AlGaN interface layer 310 and an AlGaN main body layer 320 on the side of the channel layer 20 facing away from the substrate 10, such that the Al component of the AlGaN interface layer 310 is 10% - 15%, and the Al component of the AlGaN main body layer 320 is 20% - 30%.
[0076] In the above implementation manner, the AlGaN interface layer 310 and the AlGaN main body layer 320 form the regrowth layer 30.
[0077] Step 304: Sequentially prepare a barrier layer 40 and a capping layer 50 on the side of the regrowth layer 30 facing away from the substrate 10.
[0078] In the preparation method provided by the embodiments of the present disclosure, a regrowth layer 30 is prepared on the side of the channel layer 20 facing away from the substrate 10. By ensuring the high-quality growth of the regrowth layer 30, the density of interface defects can be effectively reduced, which is beneficial to the subsequent growth of the barrier layer 40 and the cap layer 50.
[0079] The regrowth layer 30 includes an AlGaN interface layer 310 and an AlGaN main layer 320. The AlGaN interface layer 310 and the AlGaN main layer 320 are stacked along the epitaxial growth direction. The Al component of the AlGaN interface layer 310 is 10% - 15%, and the Al component of the AlGaN main layer 320 is 20% - 30%. Therefore, the overall Al component of the regrowth layer 30 gradually increases along the epitaxial growth direction. In this way, the stress and polarization effects can be balanced.
[0080] Finally, a barrier layer 40 and a cap layer 50 are sequentially prepared on the side of the regrowth layer 30 facing away from the substrate 10 to ensure the growth quality of the barrier layer 40 and the cap layer 50.
[0081] That is to say, by preparing the regrowth layer 30 on the side of the channel layer 20 facing away from the substrate 10 and utilizing the change of the Al component in the regrowth layer 30, the high-quality growth of the regrowth layer 30 is achieved, and the stress and polarization effects are effectively balanced, thereby further ensuring the growth quality of the subsequent barrier layer 40 and cap layer 50.
[0082] Figure 4 The flowchart of another preparation method of the high electron mobility transistor chip provided by the embodiments of the present disclosure is shown in Figure 4 , and the preparation method includes:
[0083] Step 401: Provide a substrate 10 and place the substrate 10 in the reaction chamber.
[0084] Exemplarily, the material of the substrate 10 is sapphire, SiC, Si, GaO, etc. In this embodiment, the material of the substrate 10 is sapphire.
[0085] In this embodiment, the reaction chamber is the reaction chamber of an MOCVD (Metal Organic Chemical Vapor Deposition) device.
[0086] Step 402: Prepare a buffer layer 60 on one side of the substrate 10.
[0087] Exemplarily, the buffer layer 60 is a GaN buffer layer grown by a two-step method.
[0088] Step 403: Prepare a channel layer 20 on the side of the buffer layer 60 facing away from the substrate 10.
[0089] Exemplarily, the channel layer 20 is a GaN layer.
[0090] Step 404: Perform plasma pretreatment on the side of the channel layer 20 facing away from the substrate 10.
[0091] Exemplarily, in step 404, the sample is placed in a mixed atmosphere of H2 / N2, and the side of the channel layer 20 facing away from the substrate 10 is bombarded with plasma with a radio frequency power of 50 - 200 W for a bombardment time of 30 - 120 s.
[0092] In the above implementation, through plasma pretreatment, the oxide layer (GaO x ) and pollutants (carbon pollution) on the surface of the channel layer 20 can be effectively removed, thereby improving the atomic-level matching of the interface between the regrown layer 30 and the channel layer 20, preparing for the subsequent growth steps, and being beneficial to improving the growth quality.
[0093] Step 405: Perform in-situ etching on the side of the channel layer 20 facing away from the substrate 10, with an etching depth of 1 - 5 nm.
[0094] Exemplarily, in step 405, in-situ etching is performed on one side of the channel layer 20 through Hydride Vapor Phase Epitaxy (HVPE).
[0095] In the above implementation, plasma pretreatment combined with in-situ etching eliminates the surface oxide layer (such as GaO) and carbon pollution, thereby improving the atomic-level matching of the interface between the regrown layer 30 and the channel layer 20, preparing for the subsequent growth steps, and being beneficial to improving the growth quality.
[0096] Step 406: Prepare an AlGaN interface layer 310 on the side of the channel layer 20 facing away from the substrate 10, such that the Al component of the AlGaN interface layer 310 is 10% - 15%.
[0097] Exemplarily, in step 406, an AlGaN interface layer 310 is prepared on one side of the channel layer 20 through an MOCVD device or an MBE (Molecular Beam Epitaxy) device.
[0098] In step 406, the growth temperature is set to 800 - 900 °C, the growth pressure is set to 50 - 300 torr, and the AlGaN interface layer 310 is grown.
[0099] In the above implementation, the AlGaN interface layer 310 is grown at a low temperature (compared with the AlGaN main layer 320 being grown at a low temperature), which can effectively inhibit the decomposition of GaN in the channel layer 20, thereby reducing interface holes.
[0100] In step 406, a plurality of sub-interface layers 311 are grown in sequence such that the Al component of each sub-interface layer 311 gradually increases along the epitaxial growth direction. The AlGaN interface layer 310 is composed of the plurality of sub-interface layers 311.
[0101] In the above implementation, by controlling the Al source during growth, such as trimethylaluminum (TMAL), the Ga source, such as trimethylgallium (TMGA), the flow rate, and the temperature gradient, etc., the Al component of each sub-interface layer 311 is distributed in a gradually changing or abrupt manner within the range of 10% to 15%.
[0102] Step 407: Prepare an AlGaN main layer 320 on the side of the AlGaN interface layer 310 facing away from the substrate 10 such that the Al component of the AlGaN main layer 320 is 20% to 30%.
[0103] Exemplarily, in step 407, an AlGaN main layer 320 is prepared on one side of the AlGaN interface layer 310 through a MOCVD device or an MBE device.
[0104] In step 407, the growth temperature is set to 1000 - 1050 °C, the growth pressure is set to 50 - 300 torr, and the AlGaN main layer 320 is grown.
[0105] In the above implementation, the AlGaN main layer 320 is grown at a high temperature (compared with the AlGaN interface layer 310 being grown at a high temperature), which can improve the crystal quality and reduce the dislocation density.
[0106] In step 407, a plurality of sub-main layers 321 are grown in sequence such that the Al component of each sub-main layer 321 gradually increases along the epitaxial growth direction. The AlGaN main layer 320 is composed of the plurality of sub-main layers 321.
[0107] In the above implementation, by controlling the Al source during growth, such as trimethylaluminum (TMAL), the Ga source, such as trimethylgallium (TMGA), the flow rate, and the temperature gradient, etc., the Al component of each sub-main layer 321 is distributed in a gradually changing or abrupt manner within the range of 20% to 30%.
[0108] Step 408: Prepare a barrier layer 40 and a cap layer 50 in sequence on the side of the regrown layer 30 facing away from the substrate 10.
[0109] Exemplarily, the barrier layer 40 is an AlGaN layer, and the cap layer 50 is a p-type GaN layer.
[0110] Through the preparation method provided by the embodiments of the present disclosure, two high electron mobility transistor chips were prepared in the laboratory, and the following is a separate introduction.
[0111] The first type:
[0112] A 4-inch SiC substrate 10 is used, a H2 / N2 mixed gas (flow ratio 3:1) is used, the plasma radio frequency power is 150 W, and the processing time is 60 seconds.
[0113] During the growth of the regrowth layer 30, an MOCVD device is used to grow a regrowth layer 30 with a thickness of 30 nm, and its Al composition linearly increases from 15% to 25%.
[0114] Through experimental verification, for this kind of high electron mobility transistor chip, the two-dimensional electron gas concentration reaches 1.2×10^13 cm -2 , and the mobility reaches 2200 cm 2 / (V·s).
[0115] The second type:
[0116] A 4-inch SiC substrate 10 is used, a H2 / N2 mixed gas (flow ratio 3:1) is used, the plasma radio frequency power is 150 W, and the processing time is 60 seconds.
[0117] During the growth of the regrowth layer 30, an MBE device is used. First, the growth temperature is set to 850 °C, and an AlGaN interface layer 310 with an Al composition of 15% and a thickness of 5 nm is grown. Then, the growth temperature is set to 1000 °C, and an AlGaN main layer 320 with an Al composition of 25% and a thickness of 25 nm is grown.
[0118] Through experimental verification, for this kind of high electron mobility transistor chip, the interface dislocation density is reduced to 5×10^8 cm -2 , and the device breakdown voltage is increased by 15%.
[0119] Unless otherwise defined, technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second", "third" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a quantity limitation, but mean that there is at least one. Terms such as "comprising" or "including" mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. Terms such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. Terms such as "upper", "lower", "left", "right", "top", "bottom" are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationships may also change accordingly.
[0120] The above is not intended to impose any formal limitations on the disclosure. Although the disclosure has been disclosed as above by way of examples, it is not intended to limit the disclosure. Any person skilled in the art, without departing from the scope of the technical solution of the disclosure, may make some modifications or variations equivalent to equivalent embodiments by using the technical content disclosed above. However, any simple modifications, equivalent variations and modifications made to the above embodiments based on the technical essence of the disclosure without departing from the content of the technical solution of the disclosure shall still fall within the scope of the technical solution of the disclosure.
Claims
1. A high electron mobility transistor chip, characterized in that, It includes a substrate (10), and a channel layer (20), a regrowth layer (30), a barrier layer (40), and a cap layer (50) stacked in sequence on one side of the substrate (10); The regrowth layer (30) includes an AlGaN interface layer (310) and an AlGaN main layer (320) stacked along the epitaxial growth direction. The Al component of the AlGaN interface layer (310) is 10% - 15%, and the Al component of the AlGaN main layer (320) is 20% - 30%.
2. The high electron mobility transistor chip according to claim 1, wherein The AlGaN interface layer (310) includes a plurality of sub-interface layers (311). Each of the sub-interface layers (311) is stacked in sequence, and the Al component of each of the sub-interface layers (311) gradually increases along the epitaxial growth direction.
3. The high electron mobility transistor chip according to claim 1, characterized in that The AlGaN main layer (320) includes a plurality of sub-main layers (321). Each of the sub-main layers (321) is stacked in sequence, and the Al component of each of the sub-main layers (321) gradually increases along the epitaxial growth direction.
4. The high electron mobility transistor chip according to claim 1, wherein Along the epitaxial growth direction, the Al component of the regrowth layer (30) varies or changes abruptly within the range of 5% - 30%.
5. The high electron mobility transistor chip according to claim 1, characterized in that The thickness of the regrowth layer (30) is 10 - 50 nm.
6. A method for fabricating a high electron mobility transistor chip, characterized in that, The preparation method is used to prepare the high electron mobility transistor chip as described in claim 1. The preparation method includes: Providing a substrate (10); Preparing a channel layer (20) on one side of the substrate (10); Sequentially preparing an AlGaN interface layer (310) and an AlGaN main layer (320) on the side of the channel layer (20) facing away from the substrate (10), such that the Al component of the AlGaN interface layer (310) is 10% - 15%, and the Al component of the AlGaN main layer (320) is 20% - 30%. The AlGaN interface layer (310) and the AlGaN main layer (320) form the regrowth layer (30); Sequentially preparing a barrier layer (40) and a cap layer (50) on the side of the regrowth layer (30) facing away from the substrate (10).
7. The preparation method according to claim 6, characterized in that, Before sequentially preparing the AlGaN interface layer (310) and the AlGaN main layer (320) on the side of the channel layer (20) facing away from the substrate (10), the preparation method includes: Performing plasma pretreatment on the side of the channel layer (20) facing away from the substrate (10); Performing in-situ etching on the side of the channel layer (20) facing away from the substrate (10), and the etching depth is 1 - 5 nm.
8. The preparation method according to claim 7, characterized in that, Performing plasma pretreatment on the side of the channel layer (20) facing away from the substrate (10) includes: Placing it in a mixed atmosphere of H2 / N2, and bombarding the side of the channel layer (20) facing away from the substrate (10) with plasma having a radio frequency power of 50 - 200 W for a bombardment time of 30 - 120 s.
9. The preparation method according to claim 6, characterized in that, Sequentially preparing the AlGaN interface layer (310) and the AlGaN main layer (320) on the side of the channel layer (20) facing away from the substrate (10) includes: Set the growth temperature to 800 - 900 °C, set the growth pressure to 50 - 300 torr, and grow the AlGaN interface layer (310); Set the growth temperature to 1000 - 1050 °C, set the growth pressure to 50 - 300 torr, and grow the AlGaN main layer (320).
10. The preparation method according to claim 9, wherein Growing the AlGaN interface layer (310) includes: Growing a plurality of sub-interface layers (311) in sequence such that the Al composition of each of the sub-interface layers (311) gradually increases along the epitaxial growth direction; Growing the AlGaN main layer (320) includes: Growing a plurality of sub-main layers (321) in sequence such that the Al composition of each of the sub-main layers (321) gradually increases along the epitaxial growth direction.