Preparation method of metalized aluminum nitride ceramic plate and semiconductor power device

Abstract

The invention discloses a preparation method of a metalized aluminum nitride ceramic plate and a semiconductor power device. The preparation method comprises the following steps: providing an aluminum nitride ceramic substrate with a target surface; wherein the roughness Rq of the target surface of the aluminum nitride ceramic substrate is 150 to 600 nm; sequentially depositing a transition layer and a functional layer on the target surface of the aluminum nitride ceramic substrate to form an AlN / transition layer / functional layer composite structural plate; and under a vacuum condition, carrying out annealing treatment on the AlN / transition layer / functional layer composite structure plate to obtain the metallized aluminum nitride ceramic plate. The metalized aluminum nitride ceramic plate is high in heat conductivity, the problems that an existing metalized aluminum nitride ceramic plate is large in interface thermal resistance and poor in reliability in high-temperature and high-heat-flow application are solved, and the heat dissipation bottleneck of a high-power semiconductor power device can be broken through and solved.

Description

TECHNICAL FIELD

[0001] The application relates to a preparation method of a metalized aluminum nitride ceramic plate and a semiconductor power device, and belongs to the technical field of electronic packaging materials and processes. BACKGROUND

[0002] With the vigorous development of 5G communication, artificial intelligence, new energy vehicles and high-performance computing industries, electronic devices are rapidly evolving towards higher power and integration, leading to a sharp rise in heat flux, so that efficient thermal management has become a core bottleneck restricting the performance and reliability of devices. Under this background, aluminum nitride ceramics have become an indispensable substrate and heat sink material in high-power electronic packaging due to their excellent thermal conductivity, reliable electrical insulation and matching thermal expansion coefficient with semiconductors. However, when a metal layer is deposited on the surface of AlN through sputtering or other processes to realize electrical interconnection, the actual heat dissipation performance of the composite structure is often limited by the high interfacial thermal resistance between AlN and the metal layer. This thermal resistance is mainly due to the severe phonon scattering at the interface, and with the continuous improvement of chip integration and operating frequency, this bottleneck effect is becoming more and more prominent, which has become a key obstacle to limiting the heat dissipation efficiency and hindering the full play of chip performance. Therefore, developing new high-performance interfacial materials and processes to break through this thermal resistance bottleneck has become a key technical problem to be solved in the field of heat dissipation of semiconductor power devices (such as semiconductor lasers LD, light-emitting diodes LED, power devices IGBT, etc.).

[0003] Chinese patent application CN103741141A discloses a method for metalizing an aluminum nitride ceramic plate, which comprises the following steps: titanium plating by physical vapor deposition: forming a certain thickness of titanium conductive layer on the surface of the cleaned aluminum nitride ceramic plate by vacuum magnetron sputtering plating; chemical copper plating: according to the conductivity of metal titanium, the aluminum nitride ceramic plate plated with titanium on the surface is placed as a cathode in an electrolytic cell containing an acidic copper sulfate plating solution, a phosphor copper plate is used as an anode, and the corresponding thickness of copper plating layer is obtained by controlling the cathode current density and plating time; heat treatment: the aluminum nitride ceramic plate plated with titanium conductive layer and copper plating layer on the surface is placed in a heat treatment furnace, heated under argon atmosphere protection, and the corresponding heat treatment temperature and holding time are controlled to realize the interfacial metallurgical bonding of aluminum nitride and titanium to form a TiN metallurgical transition layer and the interfacial metallurgical bonding of copper and titanium to form a TiCu metallurgical transition layer. This method can obtain an aluminum nitride ceramic plate with copper on the outermost layer and excellent bonding force, but the influence on the thermal conductivity is unknown. SUMMARY

[0004] In view of the deficiencies of the prior art, one of the purposes of the present application is to provide a preparation method of a metalized aluminum nitride ceramic plate with excellent thermal conductivity; and the second purpose of the present application is to provide a semiconductor power device.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows: A method for preparing a metallized aluminum nitride ceramic plate includes the following steps: S1. Provide an aluminum nitride ceramic substrate with a target surface; The roughness Rq (arithmetic mean roughness) of the target surface of the aluminum nitride ceramic substrate is 150-600 nm. S2. A transition layer and a functional layer are sequentially deposited on the target surface of the aluminum nitride ceramic substrate to form an AlN / transition layer / functional layer composite structure plate. The transition layer contains at least one of Ti, Cr, Ta, W, Zr, and Ni; the functional layer contains at least one of Cu, Ag, Au, and Al. S3. Under vacuum or protective atmosphere conditions, the AlN / transition layer / functional layer composite structure plate is annealed to obtain a metallized aluminum nitride ceramic plate.

[0006] Optionally, the roughness Rq of the target surface of the aluminum nitride ceramic substrate is 165-585 nm, preferably 175-575 nm, more preferably 180-570 nm, and further optionally 190, 200, 210, 220 / 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 520, 540 or 560 nm.

[0007] Optionally, the aluminum nitride ceramic substrate with the target surface is obtained by sequentially subjecting an aluminum nitride ceramic blank to surface pretreatment, roughening treatment, and cleaning; to obtain an aluminum nitride ceramic substrate with a target surface of a specific roughness, and to remove residual abrasive particles, oil stains, and other contaminants from the surface, in order to prepare for the subsequent deposition of transition layers and functional layers. Among them, surface pretreatment includes one or more of ultrasonic cleaning and surface activation treatment.

[0008] Optionally, ultrasonic cleaning can be performed using water, isopropanol, or acetone; surface activation treatment can be performed using argon plasma or oxygen plasma.

[0009] Optionally, the roughening treatment is graded mechanical grinding; when performing graded mechanical grinding, at least two grades of abrasives with different particle sizes are used, and grinding is performed sequentially from coarse to fine; wherein, the abrasive is at least one of diamond grinding wheel, silicon carbide grinding wheel, and alumina grinding wheel.

[0010] Mechanical grinding allows for precise control of the surface microstructure and roughness of aluminum nitride ceramic substrates, laying the foundation for significantly reducing the interfacial thermal resistance between the substrate and subsequently deposited transition and functional layers, thereby greatly improving the thermal management performance of the overall packaging structure.

[0011] Optionally, the graded mechanical grinding includes preliminary grinding and fine grinding; the abrasive used in the preliminary grinding has a mesh size of 200 to 600 mesh, and further 300 to 500 mesh; the abrasive used in the fine grinding has a mesh size of 800 to 5000 mesh, further 1000 to 4800 mesh, further 1200 to 4500 mesh, and further 1500 to 4000 mesh, for example, 2000 mesh, 2500 mesh, 3000 mesh, 3500 mesh, or 3800 mesh.

[0012] Optionally, in S2, the transition layer is made of Ti, and the functional layer is made of Cu.

[0013] Optionally, the thickness of the transition layer is 50-500 nm, further 100-450 nm, even further 150-400 nm, and still further 200-350 nm; the thickness of the functional layer is 1-10 μm, further 2-8 μm, and even further 4-6 μm.

[0014] The transition layer can improve the bonding force between the aluminum nitride ceramic substrate and the functional layer, which serves as the main conductive and thermally conductive layer.

[0015] Optionally, in S2, the deposition method includes one or more of physical vapor deposition, chemical plating, and electroplating; wherein, physical vapor deposition includes one or more of magnetron sputtering, electron beam evaporation, and thermal evaporation. Preferably, in step S2, the transition layer is deposited by magnetron sputtering, during which the sputtering power is controlled at 300-600W, more preferably 350-550W, further preferably 400-500W, the sputtering time is 10-30min, more preferably 15-25min, and even more preferably 18-22min, and the working gas pressure is 4.0×10⁻⁶. -4 Pa up to 2.0 × 10 -1 Pa, the sputtering atmosphere is an argon atmosphere or a mixture of argon and nitrogen; Optionally, the functional layer is deposited by magnetron sputtering, during which the sputtering power is controlled at 350-650W, further at 400-500W, and even further at 420-480W, the sputtering time is 8-20min, further at 10-18min, and even further at 12-16min, and the working gas pressure is 4.0×10⁻⁶. -4 Pa up to 2.0 × 10 -1 Pa, the sputtering atmosphere is an argon atmosphere or a mixture of argon and nitrogen.

[0016] Optionally, the nitrogen content in the mixed atmosphere is ≤15 vol%, further ≤10 vol%, and even further ≤5 vol%.

[0017] Optionally, in step S3, annealing is performed under vacuum conditions; wherein, during annealing, the vacuum level is controlled to be no higher than 10. -3 Pa, the annealing temperature is 400-600℃, further 450-550℃, and even further 480-520℃, and the annealing time is 30-120min, further 50-100min, and even further 60-90min; preferably, the heating rate is 2-10℃ / min, and the temperature is increased to the above-mentioned annealing temperature at this heating rate.

[0018] Annealing can promote atomic diffusion between the interfaces of the AlN / transition layer / functional layer composite structure, forming a more robust composite interface structure.

[0019] Optionally, the overall thermal conductivity of the metallized aluminum nitride ceramic plate is ≥170W / m·K, and further 175-185W / m·K.

[0020] Based on the same inventive concept, the present invention also provides: a semiconductor power device comprising a metallized aluminum nitride ceramic plate prepared by the preparation method described above.

[0021] Optionally, the semiconductor power device is one or more of a semiconductor laser (LD), a light-emitting diode (LED), and an IGBT.

[0022] This invention controls the roughness Rq of the target surface of the aluminum nitride ceramic substrate to ensure that the target surface has appropriate roughness while maintaining good flatness, avoiding local stress concentration, and laying the foundation for finally obtaining a metallized aluminum nitride ceramic plate with excellent thermal conductivity and regular interface structure.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The aluminum nitride ceramic plate of the present invention has high thermal conductivity, which solves the problem of high interfacial thermal resistance and poor reliability of existing aluminum nitride ceramic plates in high temperature and high heat flux applications, and helps to break through and solve the heat dissipation bottleneck of high power semiconductor power devices. Moreover, the aluminum nitride ceramic plate of the present invention has regular interfaces between layers, dense and continuous layers, and excellent quality, which is conducive to the normal performance of the semiconductor power devices assembled with it.

[0024] (2) The preparation method of the present invention can be achieved using existing mature equipment or means, and is easy to apply and implement. Attached Figure Description

[0025] Figure 1 The images shown are SEM images (top) and partial enlarged images (bottom) of the target surfaces of the aluminum nitride ceramic substrates in Comparative Examples 1-2 and Examples 1-3 of the present invention. In these images, a1 and a2 correspond to Comparative Example 1, b1 and b2 correspond to Example 1, c1 and c2 correspond to Example 2, d1 and d2 correspond to Example 3, and e1 and e2 correspond to Comparative Example 2.

[0026] Figure 2 The images shown are SEM images (top) and partial magnified images (bottom) of the target surfaces of the AlN / Ti composite materials prepared in Comparative Examples 1-2 and Examples 1-3 of this invention. In these images, a1 and a2 correspond to Comparative Example 1, b1 and b2 correspond to Example 1, c1 and c2 correspond to Example 2, d1 and d2 correspond to Example 3, and e1 and e2 correspond to Comparative Example 2.

[0027] Figure 3 The images show the SEM (left) and EDS (right) images of the cross-section of the metallized aluminum nitride ceramic plate prepared in Example 2 of this invention.

[0028] Figure 4 The graph shows the changes in the overall thermal conductivity of each metallized aluminum nitride ceramic plate in Comparative Examples 1-2 and Examples 1-3 of the present invention. In the graph, Sf corresponds to Comparative Example 1, P5000 corresponds to Example 1, P2000 corresponds to Example 2, P1200 corresponds to Example 3, and Rf corresponds to Comparative Example 2. Detailed Implementation

[0029] The present invention will be described in detail below with reference to embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the present invention can be combined with each other. Unless otherwise specified, the relevant percentages refer to mass percentages.

[0030] Comparative Examples 1-2, Examples 1-3 (1) Substrate selection: Five high-purity (>99.5%) and high-density (>99.5% theoretical density) aluminum nitride ceramic substrates (samples A, B, C, D, and E) were selected, each with dimensions of 10 mm × 10 mm × 1.0 mm. Each aluminum nitride ceramic substrate had two different surface roughnesses: one surface had a roughness Rq = 23.693 nm (initial smooth surface), and the other surface had a roughness Rq = 874 nm (initial rough surface). The samples were specifically grouped as follows: Sample A (Comparative Example 1): The initial smooth surface (Rq=23.693nm) was used as the target surface; Sample E (Comparative Example 2): The initial rough surface (Rq=874nm) was used as the target surface; Samples B (Example 1), C (Example 2), and D (Example 3) were polished with 5000-mesh, 2000-mesh, and 1200-mesh grinding wheels, respectively, with the initial smooth surface as the target surface, until the target roughness Rq was 185 nm, 208 nm, and 565 nm, respectively. All non-target surfaces of the samples were uniformly polished to Rq=335nm to ensure the uniqueness of the experimental variables.

[0031] Specifically, the method for obtaining a sample with the above-mentioned roughness is as follows: (a) Ultrasonic cleaning: The aluminum nitride ceramic substrate was placed in three separate cleaning tanks in sequence, and pure acetone, isopropanol and deionized water were used as cleaning solutions in sequence. Each tank was cleaned for 5 minutes in an ultrasonic cleaner to thoroughly remove organic oil, particulate matter and other adsorbed contaminants from the substrate surface.

[0032] (b) Drying: After cleaning, immediately place the substrate in a spin dryer to dry. After drying, put the aluminum nitride ceramic substrate into an oven and bake it in a nitrogen atmosphere for 30 minutes.

[0033] (c) Mechanical grinding (Examples 1-3; unless otherwise specified, this step is omitted in Comparative Examples 1-2): Equipment and consumables: A CNC precision grinding and polishing machine is used, and the grinding consumables are diamond grinding wheels and corresponding diamond grinding suspension.

[0034] Rough grinding: The aluminum nitride ceramic substrates from Examples 1-3 were fixed onto a grinding wheel using a fixture. First, a 400-grit diamond wheel was used to rough grind the corresponding target surfaces at a rotation speed of 600 rpm and a feed rate of 5 mm / min. This ensured that the ground target surfaces were free of macroscopic cracks, with a surface roughness Rq of approximately 700 nm and a substrate thickness of approximately 0.7 mm. Simultaneously, deionized water was continuously supplied as a coolant, and a diamond grinding suspension was added. The goal of this stage was to quickly remove the micro-scratches and surface stress layer of the original polished layer, establishing a uniform initial rough morphology.

[0035] Fine grinding: Diamond grinding wheels of 5000 grit (Example 1), 2000 grit (Example 2), and 1200 grit (Example 3) were used respectively. Fine grinding was performed at a rotation speed of 1200 rpm and a feed rate of 2 mm / min to ensure that the target surface was free of macroscopic cracks after grinding. The thickness of the aluminum nitride ceramic substrate was 0.5 mm, and the surface roughness Rq was 185 nm, 208 nm, and 565 nm, respectively. During fine grinding, a diamond grinding suspension was added for cooling. This stage aims to refine the microscopic peak-valley structure formed by rough grinding, eliminate deeper scratches, and precisely control the surface roughness to the preset target range, obtaining samples B, C, and D with the target roughness.

[0036] The non-target surfaces of samples A, B, C, D, and E were uniformly polished to Rq=335 nm using the same polishing process.

[0037] (d) Cleaning: In order to thoroughly remove the diamond particles and ceramic debris remaining during the grinding process, the aluminum nitride ceramic substrate was then ultrasonically cleaned for 10 min each in fresh isopropanol and deionized water.

[0038] (e) Drying: After spin drying, place the aluminum nitride ceramic substrate in a clean oven at 100°C for 10 minutes to ensure that the surface is completely dry and clean before entering the sputtering chamber.

[0039] Roughness characterization: To evaluate the effect of the polishing process on surface morphology control, the microstructure of the target surface of the treated aluminum nitride ceramic substrate was observed using scanning electron microscopy (SEM). Typical microstructure characteristics are as follows: Figure 1 As shown. To illustrate the microscopic features of surfaces with different roughnesses in detail, SEM images at different magnifications are provided for each sample, for example... Figure 1 Image a1 shows the overall morphology at 50x magnification, while a2 shows a magnified view of a1's local morphological features. Other samples also have corresponding morphology images and magnified views, visually revealing the evolution of scratches, grain exposure, and pits from smooth to rough surfaces. Subsequently, a non-contact white light interferometry profilometer was used to quantitatively characterize the roughness of each aluminum nitride ceramic substrate. To ensure data representativeness and uniformity, all samples were cleaned and dried again, and measurements were taken at five locations: the center and four corners. The arithmetic mean of these measurements was taken as the final roughness result. The measured roughness (Rq) was as follows: Rq of the target surface of sample A was 23.693 nm; Rq of the target surface of sample B was 185 nm; Rq of the target surface of sample C was 208 nm; Rq of the target surface of sample D was 565 nm; and Rq of the target surface of sample E was 874 nm. The results clearly demonstrate that a wide range of surface roughness gradients, from the near-mirror state of sample A to the highly rough state of sample E, was successfully constructed through the grinding process, verifying the feasibility of obtaining surfaces with different roughnesses.

[0040] (2) Loading and Vacuuming: Load the dried aluminum nitride ceramic substrate onto the sample stage of the high-vacuum multi-target magnetron sputtering instrument. Close the chamber, start the molecular pump and mechanical pump, and evacuate the background vacuum to a level better than 5.0 × 10⁻⁶. -4 Pa.

[0041] Plasma cleaning: Before deposition, high-purity argon (Ar) gas is introduced into the chamber to a pressure of 0.5 Pa, and a bias voltage of -1000V is applied to the aluminum nitride ceramic substrate for 3 minutes of radio frequency plasma cleaning. This step can further physically bombard and remove any extremely thin oxide layers or adsorbates that may exist on the surface, activate the surface, and enhance the adhesion of the thin film.

[0042] Ti layer deposition: Using a 99.99 wt% titanium (Ti) target, a Ti layer with a thickness of approximately 500 nm was deposited on an AlN substrate by sputtering at a DC power of 450 W for 20 min under an argon pressure of 0.5 Pa. This layer reacts with AlN during subsequent annealing to form a dense TiN transition layer, ensuring strong adhesion of the Cu layer. Thus, an AlN / Ti composite material is formed.

[0043] Cu layer deposition: Without disrupting the vacuum, a copper (Cu) target with a purity of 99.99 wt% was switched. A Cu layer with a thickness of approximately 1.2 μm was deposited on the Ti layer by sputtering at a DC power of 500 W for 14 min under an argon pressure of 0.4 Pa, serving as the primary conductive and thermal pathway. This yielded the AlN / Ti / Cu composite material.

[0044] (3) Purpose of annealing: In order to eliminate the internal stress generated during the deposition process, promote the appropriate reaction of the Ti / AlN interface to generate a more stable TiN layer, and improve the grain structure of the Cu layer, thereby further reducing the interfacial thermal resistance and improving the electrical conductivity of the film.

[0045] Annealing process: The AlN / Ti / Cu composite material is removed from the sputtering chamber and rapidly transferred to a vacuum annealing furnace. The vacuum level is reduced to below 1.0 × 10⁻⁶. -3 After Pa, the temperature is increased to 500°C at a rate of 5°C / min, held for 60 min, and then naturally cooled to room temperature in the furnace to obtain a metallized aluminum nitride ceramic plate.

[0046] AlN / Ti composite materials were prepared according to the above method, and the microstructure of the target surface was characterized by scanning electron microscopy (SEM). Figure 2 As shown in the diagram, a continuous and dense Ti layer was formed on the AlN substrate. (See magnified view). Figure 2 -a2- Figure 2As can be observed in -e2, on AlN surfaces with good roughness, the Ti layer can conformally cover and fill the micro-pits generated on the surface of the aluminum nitride ceramic substrate by mechanical grinding. However, when the roughness of the aluminum nitride ceramic substrate is large, the deposited Ti layer is not enough to completely smooth out the original undulations on its surface. This causes the surface roughness characteristics of the aluminum nitride ceramic substrate to be partially replicated and transferred to the Ti layer surface, and further transferred to the subsequently deposited Cu layer, ultimately forming an undulation similar to the substrate on the Cu layer surface.

[0047] Depend on Figure 3 It can be seen that the interfaces between the layers of the metallized aluminum nitride ceramic plate obtained in Example 2 are regular and tightly bonded, dense and continuous, and there are no defects.

[0048] Thermal conductivity testing: To evaluate the overall heat dissipation performance of the finally prepared aluminum nitride metallized ceramic plate, this invention employs a laser scintillation method for thermal conductivity testing. The specific steps include: First, a thin layer of graphite is uniformly sprayed onto both the upper and lower surfaces of the aluminum nitride metallized ceramic plate sample. This significantly improves the absorption rate of the sample surface to incident laser energy and enhances its ability to emit thermal radiation signals from its back side to the infrared detector, thereby ensuring the accuracy of the test signal. Then, the pretreated sample is placed in the instrument's testing chamber, and its front surface is bombarded with a short-duration high-energy laser pulse with a lamp voltage of 250V, a pulse width of 600μs, and a pulse energy ≥10J / Pulse. Simultaneously, the response curve of the temperature change of its back side over time is accurately recorded using an infrared detector. Finally, the thermal diffusivity of the material is calculated by analyzing this temperature rise curve, and combined with known sample density and specific heat capacity data, the overall macroscopic thermal conductivity of the aluminum nitride metallized ceramic plate is obtained. The test results can effectively evaluate the comprehensive thermal conductivity of the aluminum nitride ceramic substrate, Ti transition layer and Cu copper cladding layer and their interface, and are a key indicator for measuring the thermal management performance of the metallized aluminum nitride ceramic plate.

[0049] See Figure 4The test results unexpectedly showed that the overall thermal conductivity of the metallized aluminum nitride ceramic plate exhibited a significant and non-monotonic dependence on the surface roughness of the aluminum nitride ceramic substrate. For the five samples with progressively increasing roughness in Examples 1-3 and Comparative Examples 1-2, their thermal conductivity showed a pattern of first increasing and then decreasing, reaching a peak at a roughness Rq of 208 nm (corresponding to Example 2, P2000), where the thermal conductivity of the metallized aluminum nitride ceramic plate reached 184.23 W / m·K, demonstrating excellent thermal conductivity. Compared to Comparative Example 1 (Sf), the thermal conductivity increased by 11%. Furthermore, in the initial stage of increasing roughness, the micro-pits and protrusions of the aluminum nitride ceramic substrate increased the effective interfacial contact area between the AlN and Ti layers, thereby widening the heat flow transport channels, reducing phonon scattering at the interface, and thus improving the interfacial thermal conductivity. However, when the surface roughness exceeds a certain threshold, excessively deep pits may prevent the deposited Ti layer from achieving complete conformal coverage, thus introducing defects such as micropores or gaps at the AlN / Ti interface. These defects become new phonon scattering centers, weakening the interfacial bonding and leading to a decrease in overall thermal conductivity. Therefore, this invention, by precisely controlling the surface roughness of the target surface of the aluminum nitride ceramic substrate before deposition and annealing, can effectively optimize the thermal resistance of the AlN / Ti interface, thereby significantly improving the thermal conductivity of the metallized aluminum nitride ceramic plate.

[0050] The above embodiments should be understood as being used only to illustrate the present invention more clearly, and not to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art fall within the scope defined by the appended claims.

Claims

1. A method for producing a metallized aluminum nitride ceramic plate, characterized by, The method comprises the following steps: S1, providing an aluminum nitride ceramic substrate with a target surface; wherein the roughness Rq of the target surface of the aluminum nitride ceramic substrate is 150-600 nm; S2, sequentially depositing a transition layer and a functional layer on the target surface of the aluminum nitride ceramic substrate to form an AlN / transition layer / functional layer composite structure plate; wherein the transition layer contains at least one of Ti, Cr, Ta, W, Zr and Ni; and the functional layer contains at least one of Cu, Ag, Au and Al; S3, annealing the AlN / transition layer / functional layer composite structure plate under vacuum or protective atmosphere to obtain a metallized aluminum nitride ceramic plate.

2. The production method according to claim 1, characterized by, The roughness Rq of the target surface of the aluminum nitride ceramic substrate is 165-585 nm, preferably 175-575 nm, and more preferably 180-570 nm.

3. The preparation method according to claim 1, characterized in that, The aluminum nitride ceramic substrate with a target surface is obtained by sequentially subjecting an aluminum nitride ceramic plate blank to surface pretreatment, roughening treatment and cleaning. The surface pretreatment includes one or more of ultrasonic cleaning and surface activation treatment.

4. The production method according to claim 3, characterized by, Ultrasonic cleaning is performed using water, isopropyl alcohol or acetone; and surface activation treatment is performed using argon plasma or oxygen plasma.

5. The preparation method according to claim 3, characterized in that, The roughening treatment is a graded mechanical grinding; at least two abrasives with different particle sizes are used for the graded mechanical grinding, and the grinding is performed from coarse to fine; wherein the abrasive is at least one of a diamond grinding wheel, a silicon carbide grinding wheel and an alumina grinding wheel.

6. The preparation method according to claim 5, characterized in that, The graded mechanical grinding includes preliminary grinding and fine grinding; the abrasive used for the preliminary grinding has a mesh size of 200-600 mesh; and the abrasive used for the fine grinding has a mesh size of 800-5000 mesh.

7. The preparation method according to claim 1, characterized in that, In S2, the transition layer is composed of Ti, and the functional layer is composed of Cu; and / or, the thickness of the transition layer is 50-500 nm; and the thickness of the functional layer is 1-10 μm.

8. The method of any one of claims 1-7, wherein, In S2, the deposition method includes one or more of physical vapor deposition, chemical plating and electroplating; wherein the physical vapor deposition includes one or more of magnetron sputtering, electron beam evaporation and thermal evaporation. Preferably, in S2, the transition layer is deposited by magnetron sputtering, during which the sputtering power is controlled to be 300-600 W, the sputtering time is 10-30 min, and the working pressure is 4.0x10 -4 Pa. -1 Pa, and the sputtering atmosphere is an argon atmosphere or a mixed atmosphere of argon and nitrogen. The functional layer is deposited by magnetron sputtering, during which the sputtering power is controlled to be 350-650 W, the sputtering time is 8-20 min, the working pressure is 4.0×10 -4 Pa, the sputtering atmosphere is argon atmosphere or mixed atmosphere of argon and nitrogen. -1 Pa, the sputtering atmosphere is argon atmosphere or mixed atmosphere of argon and nitrogen.

9. The method of any one of claims 1-7, wherein, In S3, annealing treatment is performed under vacuum; wherein, during the annealing treatment, the vacuum degree is controlled to be not higher than 10 -3 Pa, the annealing temperature is 400-600℃, and the annealing time is 30-120min.

10. A semiconductor power device, characterized by, The metallized aluminum nitride ceramic plate prepared by the preparation method of any one of claims 1-9.

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