An Al 1-x Sc x N thin film, filter device and method of manufacturing the same

Abstract

This invention provides an Al 1‑x Sc x N-thin films, filtering devices, and their fabrication methods belong to the field of semiconductor material preparation technology. The Al of this invention... 1‑x Sc x The method for preparing a GaN thin film includes: providing a substrate; growing a buffer layer on the substrate; growing a GaN material layer on the buffer layer; and growing an Al layer on the GaN material layer. 1‑ x Sc x N thin film layer; wherein, the Al 1‑x Sc x The Sc component content x in the N thin film layer is 10% to 20%; the Al 1‑x Sc x The N thin film layer was peeled off from the substrate to obtain Al. 1‑x Sc x N thin film. This invention, Al 1‑x Sc x The preparation method of N thin films involves selecting Al with specific compositions. 1‑x Sc x Nitrogen materials are coherently grown on GaN material layers to prepare Al layers with low dislocation density and controllable thickness. 1‑x Sc x N thin film layer.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of semiconductor material preparation, and particularly relates to an Al 1-x Sc x N film, a filter device and a preparation method thereof. BACKGROUND

[0002] With the development of 5G communication technology, signal processing of high-frequency bands and application of high-performance BAW filters are increasingly urgent. Existing radio frequency filters mainly have two types, namely, surface acoustic wave filters and bulk acoustic wave filters, and in the bulk acoustic wave filter (BAW) of a higher frequency, piezoelectric materials such as PZT, ZnO and AlN are mainly used. In the selection of the three piezoelectric materials, problems such as electromechanical coupling coefficient, longitudinal acoustic velocity, intrinsic loss, CMOS process compatibility and the like need to be considered comprehensively. The AlN film grown in the (002) plane with good c-axis orientation and obvious piezoelectric effect has high longitudinal acoustic velocity, and is the optimal choice of piezoelectric material for the bulk acoustic wave filter device.

[0003] With the development of the field of high-frequency and high-bandwidth filters, higher sensitivity and greater bandwidth are required, which urgently requires breakthroughs in AlN material technology to improve the longitudinal piezoelectric coefficient and the electromechanical coupling coefficient. Doping other elements in the AlN film can improve the piezoelectric performance of the film to different degrees. At present, the Al 1-x Sc x N material obtained by doping Sc elements in the AlN material is a promising semiconductor material, has higher piezoelectric performance than the AlN, can replace the AlN material in the 5G radio frequency front-end FBAR / BAW / SAW filter, and has great application prospect in the field of new-generation power devices.

[0004] However, in the actual device preparation process, the Al 1-x Sc x N film is directly grown on the electrode, which is easy to cause the piezoelectric film to have large internal stress, and the edge has a certain bending degree, so that spurious waves occur when the filter works. If the film is grown on the substrate first and then transferred, the existing film growth process is difficult to match the layer transfer technology, such as directly growing the Al 1-x Sc x N film on the substrate, which will cause the grown Al 1-x Sc x N film to have problems such as lattice mismatch, abnormal nucleation and large internal stress, so that the film is difficult to meet the working requirements after being peeled off and assembled into a device.

[0005] Therefore, it is necessary to design an Al 1-x Sc x N film, a filter device and a preparation method thereof, so as to solve the above problems. SUMMARY

[0006] In view of the above disadvantages of the prior art, the present application provides an Al 1-x Sc x N film, a filter device and a preparation method thereof, when growing an Al 1-x Sc x N film on a substrate, the stress of the film is regulated to obtain an Al 1-x Sc x N film with a larger thickness and a smaller dislocation density, thereby solving the technical problem that the preparation method of the prior art cannot inhibit the intrinsic stress of the Al 1-x Sc x N film in the growth process, and further causing the prepared filter device to have a poor performance.

[0007] To achieve the above object and other related objects, the present application provides a preparation method of an Al 1-x Sc x N film, the preparation method comprising the following steps:

[0008] providing a substrate;

[0009] growing a buffer layer on the substrate;

[0010] growing a GaN material layer on the buffer layer;

[0011] growing an Al 1-x Sc x N film layer on the GaN material layer; wherein the component content x of Sc in the Al 1-x Sc x N film layer is 10% to 20%;

[0012] peeling off the Al 1-x Sc x N film layer from the substrate to obtain an Al 1-x Sc x N film.

[0013] In an example of the present application, the material of the substrate comprises any one of Si, sapphire, SiC, diamond and a GaN composite substrate.

[0014] In an example of the present application, the material of the buffer layer comprises at least one of GaN and AlGaN.

[0015] In an example of the present application, the material of the buffer layer is Al X Ga 1-XN, wherein 0≤X≤0.3, the growing buffer layer on the substrate comprises: growing buffer layer on the substrate, providing gallium source trimethyl gallium, aluminum source trimethyl aluminum and nitrogen source ammonia; the mole ratio of V / III in the growing process is 50-500, the control growing temperature is 500-900 DEG C, the growing pressure is 30-100 mbar; the thickness of the growing buffer layer is 3-50 nm.

[0016] In an example of the present application, the growing GaN material layer on the buffer layer comprises: growing GaN material layer on the buffer layer, providing gallium source trimethyl gallium and nitrogen source ammonia; the mole ratio of V / III in the growing process is 20-150, the control growing temperature is 900-1150 DEG C, the growing pressure is 50-200 mbar; the thickness of the growing GaN material layer is 100-3000 nm.

[0017] In an example of the present application, the growing Al 1-x Sc x N thin film layer on the GaN material layer comprises: growing Al 1-x Sc x N thin film layer on the GaN material layer, providing scandium source trimethyl scandium, aluminum source trimethyl aluminum and nitrogen source ammonia; the mole ratio of V / III in the growing process is 2000-5000, the control growing temperature is 950-1250 DEG C, the growing pressure is 20-80 mbar; the thickness of the growing buffer layer is 10-2000 nm; the thickness of the growing Al 1-x Sc x N thin film layer is 10-2000 nm.

[0018] In an example of the present application, the component content x of Sc in the Al 1-x Sc x N thin film layer is 18%.

[0019] In an example of the present application, the peeling off the Al 1-x Sc x N thin film layer from the substrate to obtain Al 1-x Sc x N film comprises: using laser peeling technology, focusing and scanning the GaN material layer on one side of the bottom of the substrate by laser, peeling off the GaN material layer and Al 1-x Sc x N thin film layer from the substrate to obtain Al 1-x Sc x N film.

[0020] The present application also provides an Al 1-x Sc x N film, the Al1-x Sc x N film is prepared by the method for preparing Al 1-x Sc x N film according to any one of the above embodiments.

[0021] The application also provides a filter device, which comprises an electrode and an Al 1-x Sc x N film, wherein the Al 1-x Sc x N film is prepared by the method for preparing Al 1-x Sc x N film according to any one of the above embodiments, and the electrode is arranged on at least one side of the Al 1-x Sc x N film.

[0022] The Al 1-x Sc x N film, the filter device and the method for preparing the same, the buffer layer and the GaN material layer are sequentially grown on the substrate, and then the Al 1-x Sc x N film is grown on the GaN material layer. 1-x Sc x N layer, the lattice structure of the grown Al 1-x Sc x N layer is adjusted by selecting a proper Sc element doping component, so as to reduce the lattice mismatch between the Al 1-x Sc x N and GaN, and realize the coherent growth of the Al 1-x Sc x N film on the GaN material layer, thereby obtaining an Al 1-x Sc x N film layer with a smaller dislocation density and a larger thickness, and after the Al 1-x Sc x N film layer is peeled off from the substrate, an Al 1-x Sc x N film which can be directly used to prepare the filter device is obtained. Therefore, the application effectively overcomes some practical problems in the prior art, and has high utilization value and use significance. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0024] Figure 1 Figure 1 is a schematic diagram of the structure of an Al 1-x Sc x Figure 2 is a schematic diagram of the process flow of a method for preparing an Al

[0025] Figure 2 Figure 3 is a schematic diagram of the structure of an Al 1-x Sc x Figure 4 is a schematic diagram of the process flow of a method for preparing an Al

[0026] Figure 3 Figure 5 is a schematic diagram of the principle of a method for preparing an Al 1-x Sc x Figure 6 is a schematic diagram of the process flow of a method for preparing an Al

[0027] Figure 4 Figure 7 is a schematic diagram of the structure of an Al 1-x Sc x Figure 8 is a schematic diagram of the process flow of a method for preparing an Al

[0028] Figure 5 Figure 9 is a schematic diagram of the structure of a filter device.

[0029] Element number explanation

[0030] 100, substrate; 200, buffer layer; 300, GaN material layer; 400, Al 1-x Sc x N film layer; 500, substrate layer, 600, bottom electrode layer, 700, functional layer; 800, top electrode layer. DETAILED DESCRIPTION

[0031] The present application is described herein with reference to particular embodiments for a particular application. Those skilled in the art will understand that the application is not limited to those embodiments but is applicable to other embodiments and applications as well. Persons having ordinary skill in the art will readily understand the various ways in which the present application can be practiced and will readily devise equivalents thereof without departing from the spirit and scope of the present application. It is to be understood that the following detailed description of the embodiments is given for the purpose of understanding the present application and is not intended to limit the scope of the present application. The following examples are presented to more fully describe the application and are not intended to limit the scope of the application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The following examples further illustrate the application but, of course, should not be construed as in any way limiting its scope.

[0032] When the embodiments give numerical ranges, it should be understood that unless the application indicates otherwise, every numerical range's two endpoints, and any number between the two endpoints, can be selected. Unless otherwise defined, all technical and scientific terms used in the application can be those commonly used in the art to which this application belongs, and any method, equipment, and material similar or equivalent to those described in the embodiments of the application can be used to achieve the prior art.

[0033] The application provides an Al 1-x Sc x N film preparation method, a buffer layer and a GaN material layer are introduced on a substrate, and a specific component Al 1-x Sc x N material is grown on the GaN material layer by using the characteristics that the GaN material and the Al 1-x Sc x N material are similar in crystal lattices, so that the lattice mismatch between the Al 1-x Sc x N and GaN is reduced, the coherent growth of the Al 1-x Sc x N material on the GaN material layer is realized, stress accumulation of the film during the growth process is avoided, and then the Al 1- x Sc x N film with a larger thickness and a smaller dislocation density can be grown on the GaN material layer. 1-x x After the Al 1-x Sc x N film layer is peeled off from the substrate, a piezoelectric material functional layer capable of directly preparing a filter device can be obtained.

[0034] Please refer to Figure 1 , the application provides an Al 1-x Sc x N film preparation method, which is carried out in a metal organic chemical vapor deposition (MOCVD) equipment, and trimethylaluminum (TMAl), trimethylgallium (TMGa), tricyclopentadienyl scandium (Cp3Sc), and ammonia (NH3) are respectively used as an Al source, a Ga source, a Sc source, and an N source, and high-purity hydrogen (H2) is used as a carrier gas.

[0035] Please refer to Figures 1 to 4 , an Al 1-x Sc x N film preparation method at least includes the following steps:

[0036] S1, providing a substrate 100;

[0037] S2, growing a buffer layer 200 on the substrate 100;

[0038] S3. Grow a GaN material layer 300 on the buffer layer 200;

[0039] S4. Growing Al on the GaN material layer 300 1-x Sc x N thin film layer 400, wherein the Al 1-x Sc x The Sc component content x in the N thin film layer 400 is 10% to 20%;

[0040] S5, the Al 1-x Sc x The N thin film layer 400 is peeled off from the substrate 100 to obtain Al. 1-x Sc x N thin film.

[0041] The substrate 100 provided in step S1 is made of any one of Si, sapphire, SiC, diamond and GaN. For example, the substrate 100 is made of Si, sapphire, SiC, diamond or GaN.

[0042] In some embodiments, the substrate 100 material used in step S1 is a sapphire substrate 100 that does not react with the gaseous environment.

[0043] In step S2, a buffer layer 200 is grown on the substrate 100 first. The material of the buffer layer 200 serves as a bonding layer between the substrate 100 and the GaN material layer 300. It can reduce the lattice mismatch between the substrate 100 material and the GaN material, reduce the dislocations in the GaN material layer 300, and provide a larger space for the tensile stress on the GaN material layer 300 on the substrate 100.

[0044] The material selected for the buffer layer 200 can be determined based on the material of the substrate 100 and the GaN material used, and the lattice constant of the buffer layer 200 material is between that of the substrate 100 material and the GaN material. For example, in some embodiments, the buffer layer 200 material includes at least one of GaN and AlGaN. That is, the buffer layer 200 material can be GaN or AlGaN; the buffer layer 200 material can also be a combination of GaN and AlGaN.

[0045] like Figure 1 and Figure 2 As shown, step S2 involves growing a buffer layer 200 on the substrate 100 using chemical vapor deposition. In one embodiment, the buffer layer 200 prepared in step S2 is made of Al material. X Ga 1-XN, wherein 0≤X≤0.3, the step S2 specifically comprises: placing the substrate 100 into a MOCVD device, closing a MOCVD reaction chamber, introducing H2 into the reaction chamber, the H2 gas flow rate being 130-160 L / min, for example 130 L / min, 140 L / min, 150 L / min or 160 L / min; the time being 5-10 min, for example 5 min, 6 min, 7 min, 8 min, 9 min or 10 min; the temperature of the reaction chamber being raised to 500-900 °C, for example 500 °C, 600 °C, 700 °C, 800 °C or 900 °C, the pressure of the reaction chamber being adjusted to 30-100 mbar, for example 30 mbar, 45 mbar, 60 mbar, 75 mbar, 90 mbar or 100 mbar, introducing a gallium source, for example TMGa, an aluminum source, for example TMAl, a nitrogen source, for example NH3, wherein the flow rate of TMGa is 10-150 sccm, for example 10 sccm, 30 sccm, 50 sccm, 70 sccm, 90 sccm, 110 sccm, 130 sccm or 150 sccm, the flow rate of TMAl is 10-100 sccm, for example 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm or 100 sccm, the flow rate of NH3 is 10-50 L / min, for example 10 L / min, 20 L / min, 30 L / min, 40 L / min or 50 L / min, and the V / III (V represents the fifth main group element and III represents the third main group element) molar ratio during the growth is 50-500, for example 50, 100, 200, 300, 400 or 500. In this step, the growth rate of the AlGaN buffer layer 200 is 0.5-1.5 um / h, and the growth thickness of the AlGaN buffer layer 200 is 3-50 nm, for example 3 nm, 10 nm, 20 nm, 30 nm, 40 nm or 50 nm. In addition, any value between the two endpoints of the range of each parameter above can be selected.

[0046] As Figure 1 and Figure 2As shown, step S3 grows a GaN material layer 300 on the buffer layer 200 by chemical vapor deposition. In one embodiment, step S3 specifically comprises: raising the temperature of the reaction chamber to 900-1150°C, for example 900°C, 1000°C, 1100°C or 1150°C; adjusting the pressure of the reaction chamber to 50-200mbar, for example 50mbar, 75mbar, 100mbar, 125mbar, 150mbar, 175mbar or 200mbar; introducing a gallium source, for example TMGa, and a nitrogen source, for example NH3, wherein the flow rate of TMGa is 10-120sccm, for example 10sccm, 40sccm, 70sccm, 100sccm or 120sccm, the flow rate of NH3 is 10-50L / min, for example 10L / min, 20L / min, 30L / min, 40L / min or 50L / min, and the V / III (V represents the fifth main group element and III represents the third main group element) molar ratio during growth is 20-150, for example 20, 40, 60, 80, 100, 120, 130 or 150. In this step, the growth rate of the GaN material layer 300 is 0.5-1.5um / h, and the growth thickness of the AlGaN buffer layer 200 is 100-3000nm, for example 100nm, 500nm, 1000nm, 1500nm, 2000nm, 2500nm or 3000nm. Any value within the range of each parameter and between the two endpoints of the range can be selected.

[0047] As shown in Figure 1 and Figure 2 step S4 grows an Al 1-x Sc x N thin film layer 400 on the buffer layer 200 by chemical vapor deposition. In one embodiment, step S4 specifically comprises: raising the temperature of the reaction chamber to 900-1150°C, for example 900°C, 1000°C, 1100°C or 1150°C; adjusting the pressure of the reaction chamber to 50-200mbar, for example 50mbar, 75mbar, 100mbar, 125mbar, 150mbar, 175mbar or 200mbar; introducing a gallium source, for example TMGa, and a nitrogen source, for example NH3, wherein the flow rate of TMGa is 10-120sccm, for example 10sccm, 40sccm, 70sccm, 100sccm or 120sccm, the flow rate of NH3 is 10-50L / min, for example 10L / min, 20L / min, 30L / min, 40L / min or 50L / min, and the V / III (V represents the fifth main group element and III represents the third main group element) molar ratio during growth is 20-150, for example 20, 40, 60, 80, 100, 120, 130 or 150. In this step, the growth rate of the Al 1-x Sc xThe Sc component content x in the N thin film layer 400 is 10% to 20%. In an embodiment, step S4 specifically comprises: raising the temperature of the reaction chamber to 950°C to 1250°C, for example 950°C, 1000°C, 1100°C, 1200°C or 1250°C, adjusting the pressure of the reaction chamber to 20 to 80 mbar, for example 20 mbar, 30 mbar, 40 mbar, 50 mbar, 60 mbar, 70 mbar or 80 mbar, introducing a scandium source, for example Cp3Sc, an aluminum source, for example TMAl, and a nitrogen source, for example NH3, wherein the flow rate of Cp3Sc is 5 to 100 sccm, for example 5 sccm, 10 sccm, 20 sccm, 30 sccm, 40 sccm, 50 sccm, 60 sccm, 70 sccm, 80 sccm, 90 sccm or 100 sccm, the flow rate of TMAl is 10 to 150 sccm, for example 10 sccm, 30 sccm, 50 sccm, 70 sccm, 90 sccm, 110 sccm, 130 sccm or 150 sccm, the flow rate of NH3 is 10 to 100 L / min, for example 10 L / min, 30 L / min, 50 L / min, 70 L / min or 80 L / min or 100 L / min, and the V / III (V represents the fifth main group element and III represents the third main group element) molar ratio during growth is 2000 to 5000, for example 2000, 2500, 3000, 3500, 4000, 4500 or 5000. In this step, Al 1-x Sc x The growth rate of the N thin film layer 400 is 0.01 to 1.0 um / h, and Al 1-x Sc x The growth thickness of the N thin film layer 400 is 10 to 2000 nm, for example 10 nm, 500 nm, 1000 nm, 1500 nm or 2000 nm. The two endpoints of the range given by each parameter above and any numerical value between the two endpoints can be selected.

[0048] In addition, based on the lattice structure of Al 1-x Sc x N and GaN, the Al 1-x Sc x N material can reduce the lattice mismatch of Al 1-x Sc x N and GaN, and realize better growth of the Al 1-x Sc x N thin film layer 400 on the GaN material layer 300. For example, in an embodiment, the Sc component content x in step S4 is selected to be 18% of Al 1-x Sc xThe N material grows a thin film layer on the GaN material layer 300, and the component of Al 1-x Sc x The N material has a small lattice mismatch with GaN, and can achieve coherent growth with the GaN material during growth, thereby avoiding Al 1-x Sc x The stress accumulation of the N thin film layer 400 increases with the thickness, and reduces the Al 1-x Sc x The dislocation density of the N thin film layer 400 is guaranteed while the Al 1-x Sc x The N thin film layer 400 does not bend due to the accumulation of tensile stress during growth, thereby liberating the Al 1-x Sc x The stress limitation of the N material growth thickening enables the growth of Al 1-x Sc x N thin film layer 400 on the GaN material layer.

[0049] In addition, after the growth of the Al 1-x Sc x N thin film layer 400, a cooling process is required, and in some embodiments, the cooling is performed in an N2 atmosphere, for example, the Al 1-x Sc x N thin film layer 400 is maintained at 800-850°C, the growth pressure of the N thin film layer 400 is unchanged, all the atmosphere is switched to N2, and the cooling rate is 40-45°C / min.

[0050] As shown in FIGS. Figure 3 and Figure 4 In an embodiment, step S5 uses a laser stripping technique to strip the Al 1-x Sc x N thin film layer 400 from the substrate 100. Specifically, step S5 includes the following steps: irradiating laser light on one side of the bottom of the substrate 100, adjusting the laser light to focus at the position of the GaN layer, and controlling the laser light to focus and scan the GaN material layer 300 on one side of the bottom of the substrate 100, so that the GaN material layer 300 and the Al 1-x Sc x N thin film layer 400 are stripped from the substrate 100 to obtain an Al 1-x Sc x N thin film.

[0051] Another aspect of the present application also provides an Al 1-x Sc x N thin film, which is prepared by the preparation method of the Al 1-x Sc x N thin film described in any of the above embodiments. The Al 1-x Sc x N thin film is prepared by the preparation method of the Al1-x Sc x The component content x of Sc in the AlN film is 10% to 20%.

[0052] As Figure 5 shown, the filter device further comprises the Al 1-x Sc x N film layer 400.

[0053] The filter device comprises a substrate layer 500, a bottom electrode layer 600, a functional layer 700, and a top electrode layer 800, the substrate layer 500 is provided with a groove body, the bottom electrode layer 600 is arranged on the substrate layer 500, the functional layer 700 is arranged on the bottom electrode layer 600, and the top electrode layer 800 is arranged on the functional layer 700.

[0054] The surface of the substrate layer 500 is modified with an isolation layer; the functional layer 700 comprises an Al 1-x Sc x N film layer, the Al 1-x Sc x N film layer is prepared by the preparation method of the Al 1-x Sc x N film, and the bottom electrode layer 600 and the top electrode layer 800 are respectively arranged on the top and bottom of the functional layer 700 on the substrate layer 500.

[0055] In some embodiments, the material of the substrate layer 500 is any one of Si, sapphire, SiC, diamond, and GaN, for example, the material of the substrate layer 500 is Si.

[0056] In some embodiments, the material of the isolation layer is SiO2.

[0057] In some embodiments, the electrode material of the bottom electrode layer 600 and the top electrode layer 800 comprises at least one of Al, Pt, W, Au, Mo, Ni, and Ag. For example, the electrode material of the bottom electrode layer 600 and the top electrode layer 800 adopts Mo, the Mo material electrode has better lattice matching degree with the AlN material, is conducive to the c-axis orientation growth of the AlN material on the Mo electrode, and has a larger selection than AlN in the MEMS etching process, can better perform process design, and is conducive to the electrode material of the actual process production.

[0058] In addition, the application further provides a preparation method of a filter device, the preparation method comprising the following steps:

[0059] Step a, providing a substrate layer 500, and etching a groove body on the substrate layer 500;

[0060] Step b, growing an isolation layer on the surface of the substrate layer 500;

[0061] Step c, preparing a sacrificial layer on the substrate layer 500, and planarizing the surface of the substrate layer 500 by a CMP process;

[0062] Step d, growing a bottom electrode layer 600 on the substrate layer 500, and etching the bottom electrode layer 600 according to design;

[0063] Step e, growing an Al 1-x Sc x N thin film layer on the bottom electrode layer 600, and etching the Al 1-x Sc x N thin film layer to obtain a functional layer 700;

[0064] Step f, growing a top electrode layer 800 on the functional layer 700, and etching the bottom electrode layer 600 according to design;

[0065] Step g, releasing the sacrificial layer left in the groove of the substrate layer 500 to obtain a filter device.

[0066] It should be noted that the material of the substrate layer 500 used in the preparation method can be any one of Si, sapphire, SiC, diamond and GaN. In some embodiments, the material of the substrate layer 500 is Si, and the material of the isolation layer is SiO2.

[0067] In some embodiments, the electrode material of the bottom electrode layer 600 and the top electrode layer 800 includes at least one of Al, Pt, W, Au, Mo, Ni and Ag. For example, the electrode material of the bottom electrode layer 600 and the top electrode layer 800 is Mo. The Mo material electrode has better lattice matching degree with the AlN material, which is conducive to the c-axis oriented growth of the AlN material on the Mo electrode, and the selection of AlN is larger in the MEMS etching process, which can better design the process and is conducive to the actual process of the electrode material. In the present application, the Al 1-x Sc x N thin film, a filter device and a preparation method thereof, a buffer layer and a GaN material layer are sequentially grown on a substrate, and then an Al 1-x Sc x N thin film is grown on the GaN material layer. A suitable Sc element doping component is selected to adjust the lattice structure of the grown Al 1-x Sc x N thin film layer, so as to reduce the lattice mismatch between Al 1-x Sc x N and GaN, and realize the c-axis oriented growth of Al 1-x Sc x N thin film layer on the bottom electrode layer 600, and etching the Al 1-x Sc xThe N film is grown on the GaN material layer in a coherent manner, so as to obtain Al 1-x Sc x N film layer, and the Al 1-x Sc x N film layer is peeled off from the substrate, so as to obtain the Al 1-x Sc x N film which can be directly used to prepare a filter device. Therefore, the present application effectively overcomes some practical problems in the prior art, and has high utilization value and use significance.

[0068] The above embodiments only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes completed by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. An Al 1-x Sc x The method for preparing N thin films is characterized by, include: Provide substrate; A buffer layer is grown on the substrate; The buffer layer material is Al. X Ga 1-X N, where 0 ≤ X ≤ 0.3; A GaN material layer is grown on the buffer layer; Al is grown on the GaN material layer 1-x Sc x N thin film layer, wherein the Al 1-x Sc x The Sc component content x in the N thin film layer is 10% to 20%; The Al 1-x Sc x The N thin film layer was peeled off from the substrate to obtain Al. 1-x Sc x N thin film.

2. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, The substrate material includes any one of Si, sapphire, SiC, diamond, and GaN composite substrates.

3. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, The growth of the buffer layer on the substrate includes: A buffer layer is grown on the substrate, provided with gallium source trimethylgallium, aluminum source trimethylaluminum and nitrogen source ammonia; during the growth process, the V / III molar ratio is 50 to 500, the growth temperature is controlled at 500℃ to 900℃, and the growth pressure is 30 to 100 mbar; the thickness of the grown buffer layer is 3 to 50 nm.

4. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, The process of growing a GaN material layer on the buffer layer includes: A GaN material layer is grown on the buffer layer, with trimethylgallium as the gallium source and ammonia as the nitrogen source. During the growth process, the V / III molar ratio is 20 to 150, the growth temperature is controlled at 900℃ to 1150℃, and the growth pressure is 50 to 200 mbar. The thickness of the grown GaN material layer is 100 to 3000 nm.

5. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, Al is grown on the GaN material layer 1-x Sc x N thin film layer, including: Al is grown on the GaN material layer 1-x Sc x The N thin film layer provides scandium source tricendolite, aluminum source trimethylaluminum, and nitrogen source ammonia; during growth, the V / III molar ratio is 2000–5000, the growth temperature is controlled at 950℃–1250℃, and the growth pressure is 20–80 mbar; the grown Al... 1-x Sc x The thickness of the N thin film layer is 10–2000 nm.

6. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, The Al 1-x Sc x The Sc component content x in the N thin film layer is 18%.

7. The Al according to claim 1 1-x Sc x The method for preparing N thin films is characterized by, The Al 1-x Sc x The N thin film layer was peeled off from the substrate to obtain Al. 1-x Sc x N thin films, including: Laser lift-off technology is used to focus and scan the GaN material layer on one side of the bottom of the substrate, removing the GaN material layer and Al. 1-x Sc x The N thin film layer is peeled off from the substrate to obtain Al. 1-x Sc x N thin film.

Images