A ternary amorphous insulating dielectric thin film, its preparation method and application

Abstract

This invention discloses a ternary amorphous insulating dielectric film, its preparation method, and its applications. The ternary amorphous insulating dielectric film is composed of a material with the chemical formula Al(X)N, ​​where X is selected from any one or a combination of two or more of B, Si, Zr, and Zn. The ternary amorphous insulating dielectric film has a disordered amorphous structure. This invention uses pulsed laser deposition technology to prepare the ternary amorphous insulating dielectric film. The preparation method is simple and controllable. The prepared ternary amorphous insulating dielectric film exhibits high thermodynamic stability, high dielectric constant, and low leakage current density. It can serve as an insulating material resistant to repeated impacts from strong electric fields and high currents, and is heat-resistant, showing great promise for applications in the semiconductor field.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor technology, specifically relating to a ternary amorphous insulating dielectric thin film, its preparation method, and its application. Background Technology

[0002] Third-generation wide-bandgap semiconductor materials, represented by GaN, possess a series of advantages such as direct wide bandgap, high electron mobility, high thermal conductivity, and high stability. They are ideal materials for fabricating high-frequency, high-temperature, high-voltage, high-power power electronic devices and short-wavelength, high-power optoelectronic devices, and have wide applications and a huge market prospect in optoelectronics and microelectronics. In recent years, countries and regions such as the United States, Japan, and Europe have attached great importance to the research and development of GaN devices and have achieved a series of rapid advancements. Since Khan's research group reported the world's first AlGaN / GaN HEMT device in 1993, GaNHEMT devices and monolithic microwave integrated circuits have matured in the microwave field. In the field of power devices, after more than a decade of research and development, they have begun to show promise in high-frequency switching.

[0003] However, GaN HEMTs are subjected to repeated impacts from strong electric fields and large currents during operation. The high junction temperature and high-temperature operating environment affect device performance. Problems such as large gate leakage current and current collapse severely limit the widespread application of AlGaN / GaN heterojunction HEMT devices. Compared to AlGaN / GaN HEMT devices, AlGaN / GaN MIS-HEMT devices offer many advantages. By selecting a suitable gate dielectric layer, not only can leakage current be effectively reduced, but the gate dielectric layer can also act as a surface passivation layer to effectively eliminate current collapse and significantly improve the device's breakdown voltage.

[0004] In 2000, M. Asif Khan et al. first prepared SiO2AlGaN / GaN MOS-HEMT. Since then, there have been numerous reports of using high-k dielectrics as gate dielectrics for GaN HEMTs, such as Ta2O5, Pr2O3, HfO2, and Si3N4. However, not all high-k materials are suitable as gate dielectric materials for AlGaN / GaN HEMT devices. A gate dielectric material should meet several basic requirements: (1) High crystallization temperature; Amorphous state is the most ideal structure for the gate dielectric layer. Besides being easy to prepare experimentally, the main reason is the isotropic grain structure in the amorphous state, which avoids the existence of grain boundaries in the gate dielectric layer; (2) High dielectric constant; A high k value can maintain sufficient driving current and can also maintain the same equivalent thickness (E). OT(3) It maintains good thermodynamic stability with the GaN substrate and the deviation between the GaN conduction band and the GaN conduction band is greater than 1eV; (4) It has a large band gap and a high potential barrier; (5) It has a low gate dielectric charge density and interface defects.

[0005] Al(X)N (where X is B, Si, Zr, Zn, etc.) materials and (Al)GaN barrier layers belong to the same material system, theoretically avoiding the introduction of impurities during the insulating layer deposition process and forming an ideal interface. The high thermal conductivity of Al(X)N insulating materials and the small thermal mismatch between them and the barrier layer enable devices to have good thermal stability, ensuring good thermal diffusion in high-voltage, high-power applications. However, the high-quality growth of Al(X)N gate insulating materials remains a research challenge. Commonly used thin film growth techniques include sputtering (magnetron sputtering, RF sputtering, etc.) and thermal evaporation, but films synthesized using these general physical methods have problems with interface flatness, film uniformity, and defect control. Common chemical vapor deposition methods, such as MOCVD, PECVD, and LPCVD, often require flammable, explosive, or toxic reaction sources and post-reaction gases, and the growth temperature needs to be at least 500℃ or even thousands of degrees Celsius, resulting in poor compatibility with device fabrication processes. Summary of the Invention

[0006] The main objective of this invention is to provide a ternary amorphous insulating dielectric thin film, its preparation method, and its application, so as to overcome the shortcomings of the prior art.

[0007] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0008] This invention provides a ternary amorphous insulating dielectric film, which is composed of a material with the chemical formula Al(X)N, ​​wherein X is selected from any one or a combination of two or more of B, Si, Zr, and Zn, and the ternary amorphous insulating dielectric film has a disordered amorphous structure.

[0009] Furthermore, the ternary amorphous insulating dielectric film maintains its amorphous structure at 600℃ to 1000℃.

[0010] This invention also provides a method for preparing the aforementioned ternary amorphous insulating dielectric thin film, comprising:

[0011] Provide substrate;

[0012] Furthermore, pulsed laser deposition technology is used to deposit Al(X)N ceramic target on the substrate surface to form a ternary amorphous insulating dielectric film.

[0013] Furthermore, the preparation method specifically includes: placing the substrate in a vacuum cavity, using an Al(X)N ceramic target as the target material, using nitrogen as the working gas, and employing pulsed laser deposition technology to focus a pulsed laser beam onto the Al(X)N ceramic target through a lens and a mirror, thereby depositing a ternary amorphous insulating dielectric film on the substrate surface, wherein the flow rate of the working gas is 20-40 sccm, the working gas pressure is 0.2-5.0 Pa, and the deposition time is 1 min-4.0 h.

[0014] The embodiments of the present invention also provide the application of the aforementioned ternary amorphous insulating dielectric thin film in the field of semiconductor materials.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0016] (1) This invention provides a method for preparing ternary amorphous insulating dielectric films using pulsed laser deposition technology. By comprehensively controlling a series of growth parameters such as growth temperature, metastable growth conditions are created, and the prepared ternary insulating dielectric film is in a disordered amorphous state. Its amorphous characteristics can still be maintained at 800℃, and the preparation method is simple and controllable.

[0017] (2) The leakage current density of the ternary amorphous insulating dielectric film (unannealed) and the film after high-temperature annealing prepared by this invention is both ~10 -6 A / cm 2 Its performance indicators have reached a high level compared to those of international peers in gate dielectric materials research, and can meet the requirements of high-temperature heat treatment in the current semiconductor industry.

[0018] (3) The ternary amorphous insulating dielectric film prepared by the present invention has high thermodynamic stability, high dielectric constant and low leakage current density, and can therefore be used as an insulating material that can withstand repeated impacts from strong electric fields and large currents and is resistant to high temperatures. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figures 1a-1d The images shown are high-resolution transmission microscope images and corresponding Fourier transform images of the Al(B)N thin film prepared in Example 1 of this invention and after annealing treatment.

[0021] Figure 2The X-ray diffraction patterns of the GaN substrate, Al(B)N thin film, and Al(B)N thin film after annealing in Example 1 of this invention are shown.

[0022] Figure 3 The image shows the Al(B)N thin film prepared in Example 1 of this invention and its IV curve after annealing. Detailed Implementation

[0023] In view of the deficiencies of the prior art, the inventors of this case, through long-term research and extensive practice, have proposed the technical solution of this invention. The technical solution of this invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0024] One aspect of this invention provides a ternary amorphous insulating dielectric film, wherein the ternary amorphous insulating dielectric film is composed of a material with the chemical formula Al(X)N, ​​wherein X is selected from any one or a combination of two or more of B, Si, Zr, and Zn, and the ternary amorphous insulating dielectric film has a disordered amorphous structure.

[0025] In some more specific embodiments, the ternary amorphous insulating dielectric film comprises, by atomic percentage: 45% to 55% N atoms, 5% to 30% X atoms, and the remainder comprises Al atoms.

[0026] As a preferred embodiment, the ternary amorphous insulating dielectric film exhibits an amorphous structure at 600℃ to 1000℃;

[0027] As a preferred embodiment, the thickness of the ternary amorphous insulating dielectric film is greater than 0 and less than or equal to 300 nm.

[0028] As a preferred embodiment, the leakage current density of the ternary amorphous insulating dielectric film is 10. -5 10 -7 A / cm 2 .

[0029] As a preferred embodiment, the leakage current density of the ternary amorphous insulating dielectric film after high-temperature annealing at 800℃ is ~10. -6 A / cm 2 .

[0030] Another aspect of the present invention provides a method for preparing the aforementioned ternary amorphous insulating dielectric thin film, comprising:

[0031] Provide substrate;

[0032] Furthermore, pulsed laser deposition technology is used to deposit Al(X)N ceramic target on the substrate surface to form a ternary amorphous insulating dielectric film.

[0033] Specifically, the preparation method of the ternary amorphous insulating dielectric thin film may include:

[0034] Al2O3-based GaN was cleaned and dried to serve as a substrate;

[0035] Additionally, the substrate is placed in a growth chamber under high vacuum, the laser is activated, and the pulsed laser beam is focused onto a uniformly rotating ceramic target through a lens and a mirror, generating a plasma plume in a certain N2 atmosphere, and the plasma is uniformly deposited on the substrate that is also rotating at a uniform speed.

[0036] In some more specific embodiments, the preparation method specifically includes: placing a substrate in a vacuum cavity, using an Al(X)N ceramic target as the target material, using nitrogen as the working gas, and employing pulsed laser deposition technology to focus a pulsed laser beam onto the Al(X)N ceramic target through a lens and a mirror, thereby depositing a ternary amorphous insulating dielectric film on the substrate surface, wherein the flow rate of the working gas is 20-40 sccm, the pressure of the working gas is 0.2-5.0 Pa, and the deposition time is 1 min-4.0 h.

[0037] As a preferred embodiment, the laser used in the pulsed laser deposition technology is a krypton fluoride excimer laser with a laser wavelength of 200-300 nm, a pulse width of 20-30 ns, and a maximum single pulse energy of 700 mJ.

[0038] As a preferred embodiment, the pulsed laser deposition technology uses a laser energy of 250–450 mJ and a pulse repetition frequency of 1.0–5.0 Hz.

[0039] As a preferred embodiment, the temperature of the substrate is 20-30°C, and the rotation speed of the substrate is 15-20 r / min.

[0040] As a preferred embodiment, the distance between the substrate and the target is 5 to 7.5 cm.

[0041] As a preferred embodiment, the rotational speed of the Al(X)N ceramic target is 15–20 r / min.

[0042] In some more specific embodiments, the preparation method includes: placing the substrate in a vacuum chamber, and then evacuating the chamber to a vacuum level of less than 5 × 10⁻⁶. -6 Pa.

[0043] As a preferred embodiment, the purity of the nitrogen gas is 99.999 wt.%.

[0044] As a preferred embodiment, the purity of the Al(X)N ceramic target is 99.9–99.99 wt.%.

[0045] In some more specific implementations, the Al(X)N ceramic target is obtained by high-temperature sintering of aluminum nitride with any one or more of boron nitride, silicon nitride, zirconium nitride, and zinc nitride.

[0046] Furthermore, the Al(X)N ceramic target is obtained by sintering at a high temperature of 1850°C with any one or more of aluminum nitride, boron nitride, silicon nitride, zirconium nitride, and zinc nitride.

[0047] As a preferred embodiment, the molar ratio of aluminum nitride to any one or more of boron nitride, silicon nitride, zirconium nitride, and zinc nitride is 9:1 to 1:1.

[0048] In some more specific implementations, the preparation method further includes: first cleaning and drying the substrate.

[0049] As a preferred embodiment, the cleaning process includes ultrasonic cleaning of the substrate using acetone, isopropanol, and water.

[0050] As a preferred embodiment, the drying process includes: drying the substrate obtained from the cleaning process using nitrogen gas.

[0051] As a preferred embodiment, the substrate includes an Al2O3-based GaN substrate, but is not limited thereto.

[0052] In some more specific embodiments, the method for preparing the ternary amorphous insulating dielectric film involves controlling growth parameters such as ceramic target composition, growth temperature, growth gas pressure, laser energy, and substrate-target distance using pulsed laser deposition (PLD) technology to create metastable growth conditions and obtain the amorphous insulating dielectric film. The specific steps are as follows:

[0053] (1) The ceramic target and the Al2O3-based GaN substrate dried by cleaning nitrogen gas are introduced into the sample injection chamber (vacuum degree less than 5×10). - 6 Pa) is transferred to the growth chamber, the target material is placed on the target stage in the growth chamber, and the substrate is placed on the substrate stage;

[0054] (2) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 20-30 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 0.2-3.0 Pa;

[0055] (3) Start the pulsed laser and focus the laser beam onto the ceramic target through the reflector and focusing lens. The laser energy is 250-450mJ and the laser frequency is 1-5Hz. The substrate temperature is room temperature to grow the insulating dielectric film. During the growth process, the target stage and the substrate stage rotate at a constant speed to ensure the uniformity of the film formation.

[0056] Preferably, the ceramic target material mentioned in step (1) above is prepared by hot pressing sintering using any one or more combinations of aluminum nitride, boron nitride, silicon nitride, zirconium nitride, and zinc nitride. The target material has a purity of 99.9%, wherein the molar ratio of aluminum nitride to any one or more combinations of boron nitride, silicon nitride, zirconium nitride, and zinc nitride is 9:1 to 1:1; the substrate is selected as high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0057] Preferably, the growth time in step (3) above is 0 to 4.0 h.

[0058] Another aspect of the present invention provides the use of the aforementioned ternary amorphous insulating dielectric thin film in the field of semiconductor materials.

[0059] The technical solution of the present invention will be further described in detail below with reference to several preferred embodiments and accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides detailed implementation methods and specific operation processes. However, the protection scope of the present invention is not limited to the following embodiments.

[0060] Unless otherwise specified, the experimental materials used in the examples below can be purchased from conventional biochemical reagent companies.

[0061] Example 1

[0062] A method for preparing an Al(B)N amorphous insulating dielectric thin film includes the following steps:

[0063] (1) The Al2O3-based GaN substrate was ultrasonically cleaned in acetone and isopropanol for 10 minutes, with each solution changed once during the process. It was rinsed clean with deionized water multiple times and dried with nitrogen gas to make its surface clean and free of stains and dust.

[0064] (2) The Al(B)N ceramic target (AlN∶BN=8∶2at.%) and the Al2O3-based GaN dried by cleaning nitrogen gas were introduced into the sample injection chamber (vacuum degree less than 5×10⁻⁶). -6 The target material is transferred to the growth chamber, and the substrate is placed on the substrate stage.

[0065] (3) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 20 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 0.5 Pa;

[0066] (4) Start the pulsed laser (fluorinated krypton excimer laser, with a laser wavelength of 248 nm and a pulse width of 25 ns), and focus the laser beam onto the Al(B)N ceramic target through a mirror and a focusing mirror. The laser energy is 350 mJ, the laser frequency is 2 Hz, the substrate temperature is room temperature, the substrate-target distance is 6 cm, and the Al(B)N thin film is grown. During the growth process, the target stage and the substrate stage rotate at a constant speed to ensure the uniformity of the film formation. The growth time is 2 h.

[0067] The Al(B)N ceramic target material mentioned in step (1) above is prepared by hot pressing sintering, with a target purity of 99.9% and a molar ratio of AlN powder to BN powder of 8:2. The substrate is a high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0068] Performance characterization:

[0069] Figures 1a-1b High-resolution transmission microscope image and corresponding Fourier transform image of the Al(B)N thin film prepared in this embodiment; Figures 1c-1d The images shown are high-resolution transmission microscope images and corresponding Fourier transform images of the Al(B)N thin film prepared in this embodiment after annealing at 800℃ for 20 min. It can be seen that the atoms in the AlBN thin film are randomly arranged before and after annealing, and the FFT diffraction images are all diffuse ring-shaped, proving that the film is amorphous before and after annealing.

[0070] Figure 2 The X-ray diffraction patterns of the GaN substrate, Al(B)N thin film, and Al(B)N thin film prepared in this embodiment after annealing at 800℃ for 20 min show that, apart from the diffraction peak corresponding to the GaN substrate, no other obvious crystallization peaks were observed. This indicates that the prepared AlBN thin film does not contain grains before and after annealing and is a single amorphous state.

[0071] Figure 3 The image shows the IV curves of the Al(B)N thin film prepared in this embodiment and after annealing at 800℃ for 20 min. As the voltage increases, the leakage current of the pre-annealed film gradually increases, reaching 5.6 × 10⁻⁶ at 14V. -5 A / cm2 The leakage current density of the film annealed at 800℃ was more than an order of magnitude lower than that before annealing, further indicating that the AlBN film annealed at 800℃ did not exhibit crystallization. Figure 3 The Al(B)N thin film prepared in this embodiment has high resistivity.

[0072] Example 2

[0073] A method for preparing an Al(Zr)N amorphous insulating dielectric thin film includes the following steps:

[0074] (1) The Al2O3-based GaN substrate was ultrasonically cleaned in acetone and isopropanol for 10 min in sequence, with the solution changed once during the process. It was rinsed clean with deionized water multiple times and dried with nitrogen.

[0075] (2) The Al(Zr)N ceramic target (AlN∶ZrN=9∶1 at.%) and the Al2O3-based GaN dried by cleaning nitrogen gas were introduced into the sample injection chamber (vacuum degree less than 5×10⁻⁶). -6 Pa) is transferred to the growth chamber, the target material is placed on the target stage in the growth chamber, and the substrate is placed on the substrate stage;

[0076] (3) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 30 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 3.0 Pa;

[0077] (4) Start the pulsed laser (fluorinated krypton excimer laser, with a laser wavelength of 248 nm and a pulse width of 25 ns), and focus the laser beam onto the Al(Zr)N ceramic target through a mirror and a focusing mirror. The laser energy is 350 mJ, the laser frequency is 2 Hz, the substrate temperature is room temperature, the substrate-target distance is 7 cm, and Al(Zr)N thin film is grown. During the growth process, the target stage and the substrate stage rotate at a constant speed to ensure the uniformity of film formation. The growth time is 2 h.

[0078] The Al(Zr)N ceramic target material mentioned in step (1) above is prepared by hot pressing sintering, with a target purity of 99.9% and a molar ratio of AlN powder to ZrN powder of 9:1; the substrate is selected as high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0079] Example 3

[0080] A method for preparing an Al(Si)N amorphous insulating dielectric thin film includes the following steps:

[0081] (1) The Al2O3-based GaN substrate was ultrasonically cleaned in acetone and isopropanol for 10 min in sequence, with the solution changed once during the process. It was rinsed clean with deionized water multiple times and dried with nitrogen.

[0082] (2) The Al(Si)N ceramic target (AlN∶Si3N4=1∶1at.%) and the Al2O3-based GaN dried by cleaning nitrogen gas were introduced into the sample injection chamber (vacuum degree less than 5×10⁻⁶). -6 Pa) is transferred to the growth chamber, the target material is placed on the target stage in the growth chamber, and the substrate is placed on the substrate stage;

[0083] (3) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 30 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 2.0 Pa;

[0084] (4) The pulsed laser (a krypton fluoride excimer laser with a wavelength of 248 nm and a pulse width of 25 ns) was activated. The laser beam was focused onto the Al(Si)N ceramic target using a mirror and a focusing lens. The laser energy was 400 mJ, the laser frequency was 2 Hz, the substrate temperature was room temperature, and the substrate-target distance was 7 cm. Al(Si)N thin films were grown. During the growth process, the target stage and substrate stage rotated at a constant speed to ensure the uniformity of the film formation. The growth time was 2 hours.

[0085] The Al(Si)N ceramic target material mentioned in step (1) above is prepared by hot pressing sintering, with a target purity of 99.9% and a molar ratio of AlN powder to Si3N4 powder of 1:1; the substrate is a high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0086] Example 4

[0087] A method for preparing an Al(Zn)N amorphous insulating dielectric thin film includes the following steps:

[0088] (1) The Al2O3-based GaN substrate was ultrasonically cleaned in acetone and isopropanol for 10 min in sequence, with the solution changed once during the process. It was rinsed clean with deionized water multiple times and dried with nitrogen.

[0089] (2) The Al(Zn)N ceramic target (AlN∶ZnN=7∶1 at.%) and the Al2O3-based GaN dried by cleaning nitrogen gas were introduced into the sample injection chamber (vacuum degree less than 5×10⁻⁶). -6Pa) is transferred to the growth chamber, the target material is placed on the target stage in the growth chamber, and the substrate is placed on the substrate stage;

[0090] (3) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 40 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 5.0 Pa;

[0091] (4) The pulsed laser (fluorinated krypton excimer laser with a wavelength of 200 nm and a pulse width of 20 ns) was activated. The laser beam was focused onto the Al(Zn)N ceramic target using a mirror and a focusing lens. The laser energy was 450 mJ, the laser frequency was 5 Hz, the substrate temperature was 100 °C, and the substrate-target distance was 7.5 cm. Al(Zn)N thin films were grown. During the growth process, the target stage and substrate stage rotated at a constant speed to ensure the uniformity of the film formation. The growth time was 4 h.

[0092] The Al(Zn)N ceramic target material mentioned in step (1) above is prepared by hot pressing sintering, with a target purity of 99.9% and a molar ratio of AlN powder to BN powder of 1:1; the substrate is selected as high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0093] Example 5

[0094] A method for preparing an Al(B)N amorphous insulating dielectric thin film includes the following steps:

[0095] (1) The Al2O3-based GaN substrate was ultrasonically cleaned in acetone and isopropanol for 10 minutes, with each solution changed once during the process. It was rinsed clean with deionized water multiple times and dried with nitrogen gas to make its surface clean and free of stains and dust.

[0096] (2) The Al(B)N ceramic target (AlN∶BN=5∶1 at.%) and the Al2O3-based GaN dried by cleaning nitrogen gas were introduced into the sample injection chamber (vacuum degree less than 5×10⁻⁶). -6 The target material is transferred to the growth chamber, and the substrate is placed on the substrate stage.

[0097] (3) The growth chamber was evacuated to 5 × 10⁻⁶ using a vacuum pump (mechanical pump and molecular pump). -7 Pa, high-purity nitrogen (99.999%) is introduced into the growth chamber, the N2 flow rate is adjusted to 20 sccm, and the molecular pump gate valve is adjusted to maintain the N2 pressure in the growth chamber at 0.2 Pa;

[0098] (4) Start the pulsed laser (fluorinated krypton excimer laser, with a laser wavelength of 300 nm and a pulse width of 30 ns), and focus the laser beam onto the Al(B)N ceramic target through a reflector and a focusing lens. The laser energy is 250 mJ, the laser frequency is 1.0 Hz, the substrate temperature is 600 ℃, and the substrate-target distance is 5 cm. Grow the Al(B)N thin film. During the growth process, the target stage and the substrate stage rotate at a constant speed to ensure the uniformity of the film formation. The growth time is 1 min.

[0099] The Al(B)N ceramic target material mentioned in step (1) above is prepared by hot pressing sintering. The target material purity is 99.9%, the molar ratio of AlN powder to BN powder is 5:1, and the substrate is a high-quality Al2O3-based n-GaN(002) with a dislocation density of less than 5.0 × 10⁻⁶. 8 cm -2 The resistivity is 6.0 × 10⁻⁶. -3 Ω·cm.

[0100] Comparative Example 1

[0101] A method for preparing an Al(Cr)N amorphous insulating dielectric thin film includes the following steps:

[0102] (1) The Si substrate was ultrasonically cleaned in acetone and isopropanol in sequence, rinsed with deionized water multiple times, and dried with nitrogen to make its surface clean and free of stains and dust.

[0103] (2) Transfer the AlN-Cr2N combined ceramic target (purity of 99%, specific surface area of ​​AlN / (AlN+Cr2N) target varies from 0% to 100%) and the cleaned and dried Si wafer to the growth chamber. The target is placed on the target stage of the growth chamber and the substrate is placed on the substrate stage.

[0104] (3) Use a vacuum pump (mechanical pump and molecular pump) to evacuate the growth chamber and fill the growth chamber with a nitrogen-oxygen mixture (N2:O2=6:4), and adjust the gas flow rate to maintain a gas pressure of 1Pa in the growth chamber;

[0105] (4) The pulsed laser was started, and the laser beam was focused onto the AlN-Cr2N target using a reflector and a focusing lens. The laser wavelength was 355 mJ, the laser frequency was 10 Hz, and the substrate temperature was room temperature. An Al(Cr)N thin film was grown. During the growth process, the target stage and the substrate stage rotated at a constant speed to ensure the uniformity of the film formation. The growth time was 60 min. The crystal structure of the thin film was studied by X-ray diffraction (XRD), and it was found that the thin film had a wurtzite structure.

[0106] In addition, the inventors of this case also conducted experiments with other raw materials, process operations, and process conditions described in this specification, referring to the aforementioned embodiments, and obtained relatively ideal results in all cases.

[0107] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the described embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this invention is not intended to be limited to the specific embodiments disclosed for carrying out the invention, but rather is intended to encompass all embodiments falling within the scope of the appended claims.

Claims

1. A ternary amorphous insulating dielectric thin film, characterized in that: The ternary amorphous insulating medium thin film is composed of a material with a chemical formula of Al(X)N, wherein X is selected from any one or a combination of two or more of B, Si, Zr, and Zn, and the ternary amorphous insulating medium thin film has a disordered amorphous structure; the ternary amorphous insulating medium thin film has an amorphous structure at 600-1000°C, and a leakage current density of 10 -6 A / cm² after high-temperature annealing at 800°C.

2. The ternary amorphous insulating dielectric thin film according to claim 1, characterized in that, The ternary amorphous insulating dielectric film comprises, by atomic percentage: 45%~55% N atoms, 5%~30% X atoms, and the remainder comprises Al atoms.

3. The ternary amorphous insulating dielectric thin film according to claim 1, characterized in that: The thickness of the ternary amorphous insulating dielectric film is greater than 0 and less than or equal to 300 nm.

4. The method for preparing a ternary amorphous insulating dielectric thin film according to any one of claims 1-3, characterized in that... include: Provide substrate; Furthermore, pulsed laser deposition technology is used to deposit Al(X)N ceramic target on the substrate surface to form a ternary amorphous insulating dielectric film.

5. The preparation method according to claim 4, characterized in that... Specifically, it includes: The substrate is placed in a vacuum chamber, using an Al(X)N ceramic target as the target material and nitrogen as the working gas. Pulsed laser deposition technology is used, in which a pulsed laser beam is focused onto the Al(X)N ceramic target through a lens and a mirror, thereby depositing a ternary amorphous insulating dielectric film on the substrate surface. The working gas flow rate is 20~40 sccm, the working gas pressure is 0.2~5.0 Pa, the deposition temperature is room temperature~600℃, and the deposition time is 1 min~4.0 h.

6. The preparation method according to claim 5, characterized in that: The pulsed laser deposition technology uses a krypton fluoride excimer laser with a wavelength of 200-300 nm, a pulse width of 20-30 ns, and a maximum single pulse energy of 700 mJ.

7. The preparation method according to claim 5, characterized in that: The pulsed laser deposition technology uses a laser energy of 250~450mJ and a pulse repetition frequency of 1.0~5.0Hz.

8. The preparation method according to claim 5, characterized in that: The temperature of the substrate is 20~30℃, and the rotation speed of the substrate is 15~20r / min.

9. The preparation method according to claim 5, characterized in that: The distance between the substrate and the target is 5~7.5cm.

10. The preparation method according to claim 5, characterized in that: The rotational speed of the Al(X)N ceramic target is 15~20 r / min.

11. The preparation method according to claim 5, characterized in that... include: After placing the substrate in the vacuum chamber, first evacuate the chamber to make the vacuum level less than 5 × 10⁻⁶. -6 Pa.

12. The preparation method according to claim 5, characterized in that: The purity of the Al(X)N ceramic target is 99.9~99.99 wt%.

13. The preparation method according to claim 5, characterized in that: The Al(X)N ceramic target is obtained by high-temperature sintering of aluminum nitride with any one or more of boron nitride, silicon nitride, zirconium nitride, and zinc nitride. Wherein, the molar ratio of aluminum nitride to any one or more of boron nitride, silicon nitride, zirconium nitride, and zinc nitride is 9:1 to 1:

1.

14. The preparation method according to claim 5, characterized in that... Also includes: The substrate is first cleaned and dried; wherein the cleaning process includes ultrasonic cleaning of the substrate using acetone, isopropanol and water; and the drying process includes blowing the cleaned substrate dry with nitrogen.

15. The preparation method according to claim 4, characterized in that: The substrate includes an Al2O3-based GaN substrate.

16. Use of the ternary amorphous insulating dielectric thin film according to any one of claims 1-3 in the field of semiconductor materials.

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