Transition layer for metallization of silicon carbide ceramic and preparation method of transition layer

Abstract

The invention belongs to the technical field of surface science and engineering, and particularly relates to a transition layer for metallization of silicon carbide ceramic and a preparation method of the transition layer. The transition layer for silicon carbide ceramic metallization is composed of a TiSiN layer, a TiN layer and a Ti layer which are sequentially stacked from bottom to top, and the content of Si in the TiSiN layer is 5 at%-30 at%. By replacing a Ti layer in the prior art with the transition layer for metallization of the silicon carbide ceramic, gradient transition of components and thermal expansion coefficients between the silicon carbide ceramic substrate and the copper layer is ensured, and the problem of low bonding strength caused by only depositing the Ti layer at present is solved; the silicon carbide ceramic copper-clad substrate is adopted, so that the thermal management efficiency of the electronic device is improved, the performance of the electronic device is enhanced, and the service life is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of surface science and engineering technology, specifically relating to a transition layer for metallization of silicon carbide ceramics and its preparation method. It is a process method for preparing a transition layer for metallization of silicon carbide ceramics using magnetron sputtering technology, which is particularly suitable for the preparation of ceramic-metal bonding materials with excellent interfacial bonding strength and structural uniformity. The obtained silicon carbide ceramic copper-clad substrate can be applied to the field of heat dissipation of electronic devices. Background Technology

[0002] In the field of modern electronics, especially with the increasing prominence of heat dissipation issues in high-power, high-frequency electronic devices, the demand for high-performance heat sink materials is also growing. In the field of electronic devices, heat sink materials are widely used in chip heat dissipation, heat sinks, etc., to ensure the normal operation of electronic devices. Therefore, selecting appropriate heat sink materials and processes, and improving the heat dissipation capacity of devices, has become a technological bottleneck in the development of power devices. In practical applications, the surface of ceramic packaging substrates usually needs to be covered with a layer of metal to facilitate subsequent connection and installation with metal heat sinks. Due to the significant differences in structure and properties between ceramic and metal materials, general welding processes often fail to wet the ceramic surface or form a strong bond between the two. Therefore, the process of first depositing a high-conductivity metal film on the ceramic surface to achieve a strong bond between the ceramic and the metal is called ceramic surface metallization.

[0003] Among common packaging materials, ceramic substrates possess excellent overall performance. Silicon carbide ceramic substrates, in particular, exhibit good heat resistance, high thermal conductivity, and a coefficient of thermal expansion similar to silicon, perfectly meeting the heat dissipation requirements of power devices. SiC ceramics have a coefficient of thermal expansion very close to silicon, a density of only 3.2 g / cm³, small size, high strength, excellent chemical stability, high hardness, high wear resistance, and high thermal conductivity. High-purity single-crystal SiC can achieve a thermal conductivity of up to 490 W / m·K at room temperature. Compared to commonly used ceramic heat dissipation substrates such as Al₂O₃ (30 W / m·K), AlN (260 W / m·K), and Si₃N₄ (40 W / m·K), SiC ceramics have enormous application potential in the field of heat sink materials.

[0004] Currently, common ceramic metallization methods in production include direct copper plating and active metal brazing. Although these methods are widely used, they have problems such as interface stress concentration and large differences in thermal expansion coefficients. Under operating conditions, large thermal stress is generated at the interface between the two, which can easily lead to ceramic cracking or metal layer peeling.

[0005] Based on the shortcomings of the existing technology, the problem is currently solved by depositing a transition layer between silicon carbide and copper layers. The transition layer in the existing technology is generally a Ti layer. However, directly preparing a Ti layer on a silicon carbide ceramic substrate will result in a weakened interface due to the high reactivity of the TiSi phase generated, thereby reducing the bonding strength. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention provides a transition layer for silicon carbide ceramic metallization and its preparation method. The transition layer for silicon carbide ceramic metallization consists of a TiSiN layer, a TiN layer, and a Ti layer stacked sequentially from bottom to top. By replacing the Ti layer in the prior art with the transition layer of this invention, a gradient transition in composition and thermal expansion coefficient between the silicon carbide ceramic substrate and the copper layer is ensured, solving the problem of low bonding strength caused by only depositing the Ti layer. Using a silicon carbide ceramic copper-clad substrate improves the thermal management efficiency of electronic devices, enhances their performance, and extends their service life.

[0007] Based on the above technical objectives, the present invention adopts the following technical solution: The present invention provides a transition layer for metallization of silicon carbide ceramics, which is composed of a TiSiN layer, a TiN layer and a Ti layer stacked sequentially from bottom to top. The TiSiN layer is chosen to replace the Ti layer to reduce reactivity. Si helps to reduce abrupt changes in composition at the interface and decrease the difference in thermal expansion coefficients between the underlayer (TiSiN layer) and the SiC substrate (silicon carbide ceramic substrate), thereby effectively improving the bonding strength at the interface. In addition, at the SiC substrate surface, the silicon nitride generated in situ by the reaction of deposited Si with nitrogen matches the SiC substrate lattice, which helps to reduce the interfacial stress caused by lattice distortion. Both silicon nitride and TiN have diffusion blocking effects, which can inhibit the diffusion of Ti atoms into the SiC substrate and avoid the formation of brittle phases, thereby effectively improving the bonding strength at the interface. Directly connecting the TiSiN layer and the Ti layer will result in abrupt changes at the interface, which is not conducive to bonding. By using the gradient reduction of Si element content and nitrogen flow rate in the TiSiN layer / TiN layer / Ti layer, a smooth transition of the transition layer for metallization of silicon carbide ceramic is achieved. The mutual diffusion of metals between the Ti layer and the copper-plated metal layer further ensures the bonding between the two layers.

[0008] In the TiSiN layer, the Si content is 5 at% to 30 at, and the Ti content is 10 at% to 30 at; in the TiN layer, the Ti content is 20 at% to 40 at.

[0009] Preferably, the thickness of the transition layer for metallizing silicon carbide ceramic is 450 nm to 550 nm.

[0010] Preferably, the thickness of the TiSiN layer is 180nm~220nm. If it is too thin, the reaction will be insufficient, thus reducing the bonding strength; if it is too thick, the cost will be too high.

[0011] Preferably, the thickness of the TiN layer is 180nm~220nm. If it is too thin, the reaction will be insufficient, thus reducing the bonding strength; if it is too thick, the cost will be too high.

[0012] Preferably, the thickness of the Ti layer is 80nm~120nm. If it is too thin, the reaction will be insufficient, thus reducing the bonding strength; if it is too thick, the cost will be too high.

[0013] This invention also protects a method for preparing a transition layer for metallization of silicon carbide ceramics, comprising the following steps: first depositing a TiSiN layer by magnetron sputtering, then depositing a TiN layer on the TiSiN layer, and finally depositing a Ti layer on the TiN layer to obtain a transition layer for metallization of silicon carbide ceramics.

[0014] Preferably, the TiSiN layer deposition method is as follows: the gas pressure in the vacuum chamber of the magnetron sputtering equipment is evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of not less than 99.9% are introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 1~3:5 (too low a nitrogen flow rate will result in too low content of in-situ generated TiN and silicon nitride, while too high a nitrogen flow rate will easily poison the target). At a working pressure of 0.2Pa~0.4Pa, the power supplies for sputtering the Si target and Ti target are turned on simultaneously, and the power ratio of the Si target to the Ti target is set to 1:1~4 (too high silicon content will cause silicon elements to accumulate at the interface, thus affecting the bonding strength; too low a content will cause abrupt changes in the composition of silicon elements generated by the reaction at the interface, which will not play a gradient transition role). A TiSiN layer is deposited on the surface of the silicon carbide ceramic substrate with a substrate bias of -200V. When the TiSiN layer thickness reaches 90nm~110nm, the power of the Ti target is fixed, and the power ratio of the Si target to the Ti target is reduced to 0:1~4. At this time, only the power of the Si target is changed and reduced to 0 at a constant rate until the required thickness of the TiSiN layer is achieved.

[0015] Preferably, the TiN layer deposition method is as follows: the gas pressure in the vacuum chamber of the magnetron sputtering equipment is evacuated to ≤5×10⁻⁶. -3After Pa, nitrogen and argon with a purity of not less than 99.9% are introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 2:5 (too low a nitrogen flow rate will result in too low a TiN content generated in situ, while too high a nitrogen flow rate can easily poison the target). At a working pressure of 0.2 Pa to 0.4 Pa, the sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the surface of the TiSiN layer. When the TiN layer thickness reaches 90 nm to 110 nm, the nitrogen to argon flow rate ratio is reduced from 2:5 to 0:5. The argon flow rate is fixed, and only the nitrogen flow rate is changed and uniformly reduced to 0 until the required thickness of the TiN layer is achieved.

[0016] Preferably, the method for depositing the Ti layer is as follows: the gas pressure in the vacuum chamber of the magnetron sputtering equipment is evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of not less than 99.9% is introduced into the vacuum chamber. When the working pressure is 0.2Pa~0.4Pa, the sputtering Ti target power supply is turned on and the substrate bias voltage is -60V to deposit a Ti layer on the TiN layer surface.

[0017] The present invention also protects a silicon carbide ceramic copper-clad substrate, which is made by using the above-mentioned silicon carbide ceramic metallization transition layer. The silicon carbide ceramic copper-clad substrate is made by stacking a silicon carbide ceramic substrate, a silicon carbide ceramic metallization transition layer and a copper layer in sequence from bottom to top.

[0018] This invention also protects a method for preparing a silicon carbide ceramic copper-clad substrate, comprising the following steps: A transition layer for silicon carbide ceramic metallization is deposited on a silicon carbide ceramic substrate using magnetron sputtering, and then a copper layer is deposited on the transition layer for silicon carbide ceramic metallization.

[0019] Preferably, the silicon carbide ceramic substrate is fixed on the sample stage within the vacuum chamber of the magnetron sputtering equipment, and the titanium, copper, and silicon targets are placed at their respective target positions within the magnetron sputtering vacuum chamber. The silicon carbide ceramic substrate is then subjected to glow discharge sputtering cleaning. The glow discharge sputtering cleaning process involves evacuating the vacuum chamber of the magnetron sputtering equipment to a pressure ≤5×10⁻⁶. - 3 After Pa, argon gas with a purity of not less than 99.9% is introduced, and the gas pressure in the vacuum chamber is controlled at 0.3Pa~0.5Pa. A bias voltage of -200V~-500V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 30min~40min to obtain a clean silicon carbide ceramic substrate.

[0020] Preferably, the Cu layer deposition method is as follows: the gas pressure in the vacuum chamber of the magnetron sputtering equipment is evacuated to ≤5×10⁻⁶. -3After Pa, argon gas with a purity of not less than 99.9% is introduced into the vacuum chamber. When the working gas pressure is 0.2Pa~0.4Pa, the sputtering Cu target power supply is turned on, the substrate bias voltage is -60V, and a Cu layer with a thickness of 1μm~3μm is deposited on the Ti layer.

[0021] Compared with the prior art, the beneficial effects of the present invention are reflected in: 1. This invention achieves a reliable connection between a silicon carbide ceramic substrate and metallic copper by constructing a three-layer gradient transition layer of TiSiN / TiN / Ti, ensuring a gradient transition in composition and thermal expansion coefficient between the silicon carbide ceramic substrate and the copper cladding layer. The thermal expansion coefficients of SiC and Cu are 4.3 and 17 (in units of 10⁻¹⁰), respectively. -6 / K), while Ti and TiN are 8.8 and 9.3, respectively, which is in between. TiSiN controls the silicon content so that its thermal expansion coefficient is between 6 and 8.5, thereby achieving a gradient increase in thermal expansion coefficient from bottom to top, reducing the interfacial thermal stress between silicon carbide ceramic and copper clad layer under operating conditions, so as to solve the existing problems of ceramic cracking or metal layer peeling.

[0022] 2. This invention can regulate the gradient transition of Si elements from the TiSiN layer to the TiN layer by changing the power ratio of Si target to Ti target in the TiSiN layer (too high silicon content will cause silicon elements to accumulate at the interface, thus affecting the bonding strength; too low silicon content will cause abrupt changes in the composition of silicon elements generated by the reaction at the interface, which will not play the role of gradient transition), and control the reaction between Ti elements and SiC substrate at the interface (too high Ti content will cause the interface reaction to be too strong, and the generation of TiSi phase will lead to interface weakening; too low Ti content will cause too few atoms to participate in the interface reaction, and the bonding strength cannot be guaranteed by chemical bonding).

[0023] 3. This invention uses magnetron sputtering to prepare silicon carbide ceramic copper-clad substrates. The preparation method is simple, controllable, and easy to commercialize. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the silicon carbide ceramic copper-clad substrate prepared by the present invention; wherein, the TiSiN layer / TiN layer / Ti layer is a three-layer gradient transition layer, and the Cu layer is a metallization layer.

[0025] Figure 2 This is a cross-sectional morphology diagram of the TiSiN layer, TiN layer, Ti layer and copper layer on the surface of the silicon carbide ceramic copper-clad substrate in Example 2.

[0026] Figure 3 Figure 1 shows the elemental distribution diagrams of Examples 1 and 2 obtained by glow discharge spectroscopy; wherein, (a) is the transition layer for metallization of silicon carbide ceramic in Example 1; and (b) is the transition layer for metallization of silicon carbide ceramic after copper plating in Example 2.

[0027] Figure 4 These are morphology images of silicon carbide ceramic copper-clad substrates prepared in Example 2 and Comparative Example 1 after multiple scratches under 5N constant load; wherein, (a) is a morphology image of the transition layer for silicon carbide ceramic metallization in Example 2 after 30 scratches; (b) is a morphology image of the TiN / Ti transition layer in Comparative Example 1 after 15 scratches.

[0028] Figure 5 These are comparative images showing the minimum number of cycles at which the silicon carbide ceramic copper-clad substrates prepared in Examples 1, 2, and Comparative Example 1 exhibited peeling off due to constant-load scratches. Detailed Implementation

[0029] The technical solutions of the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] This invention prepares a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition layer structure of TiSiN / TiN / Ti. Using magnetron sputtering technology, Ti and Si targets are first sputtered and reacted with nitrogen in a vacuum chamber to deposit a TiSiN layer on the clean surface of the silicon carbide ceramic copper-clad substrate. By adjusting the power ratio of Si and Ti targets, the composition of the transition layer for silicon carbide ceramic metallization gradually transitions from the TiSiN layer to the TiN layer. Then, by gradually reducing the nitrogen flow rate, the composition of the TiN layer gradually transitions to the Ti layer.

[0031] This invention provides a method for preparing a silicon carbide ceramic copper-clad substrate with a TiSiN layer / TiN layer / Ti layer multilayer transition layer structure, the specific steps of which are as follows: Step 1: Fix the silicon carbide ceramic substrate on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and place the titanium, copper, and silicon targets at their respective target positions inside the magnetron sputtering vacuum chamber. Evacuate the vacuum chamber of the magnetron sputtering equipment to ≤5×10⁻⁶. -3 After Pa, the silicon carbide ceramic substrate is cleaned using glow discharge to obtain a clean silicon carbide ceramic substrate.

[0032] Step 2: Evacuate the vacuum chamber of the magnetron sputtering equipment to ≤5×10⁻⁶. -3After Pa, nitrogen and argon with a purity of not less than 99.9% are introduced into the vacuum chamber, with the flow ratio of nitrogen to argon ranging from 1:5 to 3:5 and the working pressure from 0.2 Pa to 0.4 Pa. At the same time, the power supplies of the Si target and Ti target are turned on, and the power ratio of the Si target to the Ti target is adjusted to a range of 1:1 to 1:4. The substrate bias voltage is -200V. When the thickness of the TiSiN layer reaches 90nm to 110nm, the power of the Ti target is fixed, and the power ratio of the Si target to the Ti target is uniformly reduced to 0:1 to 4. The TiSiN layer is deposited to continue, and a TiSiN layer with a total thickness of 180nm to 220nm is obtained on the clean silicon carbide ceramic substrate.

[0033] Step 3: Evacuate the vacuum chamber of the magnetron sputtering equipment to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of not less than 99.9% are introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 2:5 and a working pressure of 0.2 Pa to 0.4 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 90 nm to 110 nm, the argon flow rate is fixed, and the nitrogen to argon flow rate ratio is uniformly reduced from 2:5 to 0:5. The total thickness of the TiN layer is 180 nm to 220 nm.

[0034] Step 4: Evacuate the vacuum chamber of the magnetron sputtering equipment to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of not less than 99.9% is introduced into the vacuum chamber at a working pressure of 0.2 Pa to 0.4 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 80 nm to 120 nm is deposited on the TiN layer.

[0035] Step 5: Evacuate the vacuum chamber of the magnetron sputtering equipment to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of not less than 99.9% is introduced into the vacuum chamber at a working pressure of 0.2 Pa to 0.4 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 1 μm to 3 μm is deposited on the Ti transition layer.

[0036] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below with reference to specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention. Unless otherwise specified, the experimental methods and detection methods described in the following embodiments are conventional methods; unless otherwise specified, the reagents and materials described are commercially available.

[0037] Example 1 This embodiment provides a method for preparing a silicon carbide ceramic copper-clad substrate, which utilizes magnetron sputtering technology to sequentially deposit a TiSiN layer / TiN layer / Ti layer three-layer gradient transition layer and a Cu metal layer on the surface of the silicon carbide ceramic substrate, including the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium, copper, and silicon targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of 99.99% is introduced, and the gas pressure in the vacuum chamber is controlled at 0.5 Pa. A bias voltage of -500V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 30 minutes to obtain a clean silicon carbide ceramic substrate.

[0038] Step 2, Deposit TiSiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 3:5 and a working pressure of 0.4 Pa. At the same time, the power supplies for sputtering the Si and Ti targets were turned on, and the power ratio of the Si and Ti targets was set to 1:1. The substrate bias voltage was -200V. When the TiSiN layer thickness reached 100nm, the power ratio of the Si and Ti targets was gradually reduced to 0:1, and a TiSiN layer with a thickness of 100nm was deposited. A TiSiN layer with a total thickness of 200nm was deposited on the clean silicon carbide ceramic substrate surface.

[0039] Step 3: Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon are introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.4 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 100 nm, the nitrogen to argon flow ratio is gradually reduced from 2:5 to 0:5, and a TiN layer with a thickness of 100 nm is deposited. A TiN layer with a total thickness of 200 nm is deposited on the TiSiN layer surface.

[0040] Step 4: Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.4 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 100 nm is deposited on the TiN layer.

[0041] Step 5: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.4 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 2 μm is deposited on the Ti layer surface of the three-layer gradient transition layer of TiSiN / TiN / Ti.

[0042] After the coating process is complete, the gas supply is stopped, and a vacuum state is maintained. The sample is then removed after cooling to room temperature in the furnace. This yields a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition structure of TiSiN / TiN / Ti layers and a copper layer formed on the surface of the silicon carbide ceramic substrate. A schematic diagram of its structure is shown below. Figure 1 As shown.

[0043] Example 2 This embodiment provides a method for preparing a silicon carbide ceramic copper-clad substrate, which utilizes magnetron sputtering technology to sequentially deposit a TiSiN layer / TiN layer / Ti layer three-layer gradient transition layer and a Cu metal layer on the surface of the silicon carbide ceramic substrate, including the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium, copper, and silicon targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of 99.99% is introduced, and the gas pressure in the vacuum chamber is controlled at 0.5 Pa. A bias voltage of -500V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 30 minutes to obtain a clean silicon carbide ceramic substrate.

[0044] Step 2, Deposit TiSiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 2:5 and a working pressure of 0.3 Pa. At the same time, the power supplies for sputtering the Si and Ti targets were turned on, and the power ratio of the Si and Ti targets was set to 1:2. The substrate bias voltage was -200V. When the TiSiN layer thickness reached 100nm, the power ratio of the Si and Ti targets was gradually reduced to 0:2, and a TiSiN layer with a thickness of 100nm was deposited. A TiSiN layer with a total thickness of 200nm was deposited on the clean silicon carbide ceramic substrate surface.

[0045] Step 3: Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3After Pa, nitrogen and argon are introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.3 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 100 nm, the nitrogen to argon flow ratio is gradually reduced from 2:5 to 0:5, and a TiN layer with a thickness of 100 nm is deposited. A TiN layer with a total thickness of 200 nm is deposited on the TiSiN layer surface.

[0046] Step 4: Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.3 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 100 nm is deposited on the TiN layer.

[0047] Step 5: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.3 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of about 2 μm is deposited on the Ti layer surface of the three-layer gradient transition layer of TiSiN / TiN / Ti.

[0048] After the coating is completed, the gas supply is stopped, and a vacuum state is maintained. After the furnace cools to room temperature, the sample is taken out, thus obtaining a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition layer structure of TiSiN layer / TiN layer / Ti layer and a copper layer formed on the surface of the silicon carbide ceramic substrate.

[0049] Example 3 This embodiment provides a method for preparing a silicon carbide ceramic copper-clad substrate, which utilizes magnetron sputtering technology to sequentially deposit a TiSiN layer / TiN layer / Ti layer three-layer gradient transition layer and a Cu metal layer on the surface of the silicon carbide ceramic substrate, including the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium, copper, and silicon targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of 99.99% is introduced, and the gas pressure in the vacuum chamber is controlled at 0.3 Pa. A bias voltage of -200V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 40 minutes to obtain a clean silicon carbide ceramic substrate.

[0050] Step 2, Deposit TiSiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶.-3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 1:5 and a working pressure of 0.2 Pa. At the same time, the power supplies for sputtering the Si and Ti targets were turned on, and the power ratio of the Si and Ti targets was set to 1:4. The substrate bias voltage was -200V. When the TiSiN layer thickness reached 100nm, the power ratio of the Si and Ti targets was gradually reduced to 0:4, and a TiSiN layer with a thickness of 100nm was deposited. A TiSiN layer with a total thickness of 200nm was deposited on the clean silicon carbide ceramic substrate surface.

[0051] Step 3: Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon are introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.2 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 100 nm, the nitrogen to argon flow ratio is gradually reduced from 2:5 to 0:5, and a TiN layer with a thickness of 100 nm is deposited. A TiN layer with a total thickness of 200 nm is deposited on the TiSiN layer surface.

[0052] Step 4: Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 100 nm is deposited on the TiN layer.

[0053] Step 5: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 2 μm is deposited on the Ti layer surface of the three-layer gradient transition layer of TiSiN / TiN / Ti.

[0054] After the coating is completed, the gas supply is stopped, and a vacuum state is maintained. After the furnace cools to room temperature, the sample is taken out, thus obtaining a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition layer structure of TiSiN layer / TiN layer / Ti layer and a copper layer formed on the surface of the silicon carbide ceramic substrate.

[0055] Example 4 This embodiment provides a method for preparing a silicon carbide ceramic copper-clad substrate, which utilizes magnetron sputtering technology to sequentially deposit a TiSiN layer / TiN layer / Ti layer three-layer gradient transition layer and a Cu metal layer on the surface of the silicon carbide ceramic substrate, including the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium, copper, and silicon targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of 99.99% is introduced and the pressure in the vacuum chamber is controlled at 0.4 Pa. A bias voltage of -400V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 35 minutes to obtain a clean silicon carbide ceramic substrate.

[0056] Step 2, Deposit TiSiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a nitrogen to argon flow rate ratio of 2:5 and a working pressure of 0.2 Pa. At the same time, the power supplies for sputtering the Si and Ti targets were turned on, and the power ratio of the Si and Ti targets was set to 1:3. The substrate bias voltage was -200V. When the TiSiN layer thickness reached 90 nm, the power ratio of the Si and Ti targets was gradually reduced to 0:3, and a TiSiN layer with a thickness of 90 nm was deposited. A TiSiN layer with a total thickness of 180 nm was deposited on the clean silicon carbide ceramic substrate surface.

[0057] Step 3: Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon are introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.3 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 110 nm, the nitrogen to argon flow ratio is gradually reduced from 2:5 to 0:5, and an 80 nm thick TiN layer is deposited. A total TiN layer with a thickness of 190 nm is deposited on the TiSiN layer surface.

[0058] Step 4: Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 80 nm is deposited on the TiN layer.

[0059] Step 5: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 3 μm is deposited on the Ti layer surface of the three-layer gradient transition layer of TiSiN / TiN / Ti.

[0060] After the coating is completed, the gas supply is stopped, and a vacuum state is maintained. After the furnace cools to room temperature, the sample is taken out, thus obtaining a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition layer structure of TiSiN layer / TiN layer / Ti layer and a copper layer formed on the surface of the silicon carbide ceramic substrate.

[0061] Example 5 This embodiment provides a method for preparing a silicon carbide ceramic copper-clad substrate, which utilizes magnetron sputtering technology to sequentially deposit a TiSiN layer / TiN layer / Ti layer three-layer gradient transition layer and a Cu metal layer on the surface of the silicon carbide ceramic substrate, including the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium, copper, and silicon targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas with a purity of 99.99% is introduced and the pressure in the vacuum chamber is controlled at 0.4 Pa. A bias voltage of -400V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 35 minutes to obtain a clean silicon carbide ceramic substrate.

[0062] Step 2, Deposit TiSiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a flow rate ratio of nitrogen to argon of 2:5 and a working pressure of 0.2 Pa. At the same time, the power supplies for sputtering the Si and Ti targets were turned on, and the power ratio of the Si and Ti targets was set to 1:3. The substrate bias voltage was -200V. When the TiSiN layer thickness reached 110 nm, the power ratio of the Si and Ti targets was gradually reduced to 0:3, and a TiSiN layer with a thickness of 110 nm was deposited. A TiSiN layer with a total thickness of 220 nm was deposited on the clean silicon carbide ceramic substrate surface.

[0063] Step 3: Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3After Pa, nitrogen and argon are introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.3 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A TiN layer is deposited on the TiSiN layer surface. When the TiN layer thickness reaches 110 nm, the nitrogen to argon flow ratio is gradually reduced from 2:5 to 0:5, and an 80 nm thick TiN layer is deposited. A total TiN layer with a thickness of 190 nm is deposited on the TiSiN layer surface.

[0064] Step 4: Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 120 nm is deposited on the TiN layer.

[0065] Step 5: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.2 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 1 μm is deposited on the Ti layer surface of the three-layer gradient transition layer of TiSiN / TiN / Ti.

[0066] After the coating is completed, the gas supply is stopped, and a vacuum state is maintained. After the furnace cools to room temperature, the sample is taken out, thus obtaining a silicon carbide ceramic copper-clad substrate with a three-layer gradient transition layer structure of TiSiN layer / TiN layer / Ti layer and a copper layer formed on the surface of the silicon carbide ceramic substrate.

[0067] Comparative Example 1 This comparative example provides a method for preparing a silicon carbide ceramic copper-clad substrate, which involves sequentially depositing a TiN / Ti bilayer transition layer and a Cu metal layer on the surface of a silicon carbide ceramic substrate using magnetron sputtering technology. The specific method includes the following steps: Step 1, Glow Sputtering Cleaning Treatment: A silicon carbide ceramic substrate was fixed on the sample stage inside the vacuum chamber of the magnetron sputtering equipment, and titanium and copper targets were placed at their respective target positions within the vacuum chamber. The pressure inside the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. - 3 After Pa, argon gas with a purity of 99.99% is introduced, and the gas pressure in the vacuum chamber is controlled at 0.5 Pa. A bias voltage of -500V is applied to the silicon carbide ceramic substrate, and glow discharge cleaning is performed for 30 minutes to obtain a clean silicon carbide ceramic substrate.

[0068] Step 2, Deposit TiN layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶.-3 After Pa, nitrogen and argon with a purity of 99.99% were introduced into the vacuum chamber, with a nitrogen to argon flow ratio of 2:5 and a working pressure of 0.4 Pa. The sputtering Ti target power supply was turned on, and the substrate bias voltage was -60V. A TiN layer was deposited on the clean silicon carbide ceramic substrate. When the TiN layer thickness reached 100 nm, the nitrogen to argon flow ratio was gradually reduced from 2:5 to 0:5, and a TiN layer with a thickness of 300 nm was deposited. A total TiN layer with a thickness of 400 nm was deposited on the silicon carbide ceramic substrate.

[0069] Step 3, Deposit Ti layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.4 Pa. The sputtering Ti target power supply is turned on, and the substrate bias voltage is -60 V. A Ti layer with a thickness of 100 nm is deposited on the TiN layer.

[0070] Step 4: Deposit Cu metal layer: The pressure in the vacuum chamber of the magnetron sputtering equipment was evacuated to ≤5×10⁻⁶. -3 After Pa, argon gas is introduced into the vacuum chamber at a working pressure of 0.4 Pa. The sputtering Cu target power supply is turned on, and the substrate bias voltage is -60 V. A Cu metal layer with a thickness of 2 μm is deposited on the Ti layer surface of the TiN / Ti layer double transition layer.

[0071] After the coating is completed, the gas supply is stopped, and a vacuum state is maintained. After the furnace cools to room temperature, the sample is taken out, thus obtaining a silicon carbide ceramic copper-clad substrate with a TiN / Ti double-layer transition layer structure and a copper layer formed on the surface of the silicon carbide ceramic substrate.

[0072] Table 1 Comparison of structural composition, thickness, and transition layer preparation conditions of silicon carbide ceramic copper-clad substrates Test 1: Cross-sectional morphology analysis: The cross-sectional morphology of the TiSiN / TiN / Ti gradient transition layer and copper layer of the silicon carbide ceramic copper-clad substrate prepared in Example 2 was analyzed. The results are shown in […]. Figure 2 The cross-sectional morphology of the remaining embodiments is similar to... Figure 2 There is no significant difference. Figure 2 The results analysis showed that the TiSiN / TiN / Ti gradient transition layer and copper layer deposited in Example 2 had a dense microstructure, and the film (copper layer) was tightly bonded to the SiC substrate interface. No obvious interface separation or gaps were observed, and the film surface did not show any undulations, and there were no obvious defects at the interface.

[0073] Test 2: Glow Discharge Spectroscopy Analysis: Glow discharge spectroscopy analysis was performed on the TiSiN / TiN / Ti gradient transition layer of the silicon carbide ceramic copper-clad substrates prepared in Examples 1 and 2. The results are shown in […]. Figure 3 .Depend on Figure 3 Analysis of the results shows that the Si content at the interface of the TiSiN / TiN / Ti gradient transition layer film deposited in Example 1 is 30%, and the SiTi atomic ratio gradually decreases from 2:1 to 0:1; the Si content at the interface of the TiSiN / TiN / Ti gradient transition layer film deposited in Example 2 is 20%, and the SiTi atomic ratio gradually decreases from 1:1 to 0:1.

[0074] Test 3: Constant Small Load Reciprocating Scratch Test: A constant small load reciprocating scratch test was conducted on the gradient transition layer of the silicon carbide ceramic copper-clad substrates prepared in Examples 1, 2, and Comparative Example 1, and the surface condition of the scratch after the minimum number of scratch cycles that resulted in peeling was observed. In the scratch test, the diamond indenter diameter was 0.2 mm, and the test was conducted under a constant load of 5 N, with a scratch length of 3 mm. The results are shown below. Figure 4 , 5 .

[0075] like Figure 4 As shown in Figure (a), after 30 cycles of scratch testing, the TiSiN / TiN / Ti gradient transition layer only exhibits peeling at the edges; while... Figure 4 In Figure (b), after 15 scratch tests, the TiN / Ti transition layer showed obvious peeling in the entire scratch area. This cycle can be determined as the critical peeling cycle, so as to qualitatively compare the bonding strength of different systems.

[0076] Depend on Figure 5 The results show that the bonding strength of the TiSiN layer / TiN layer / Ti layer gradient transition layer system in Examples 1 and 2 is better than that of the TiN layer / Ti layer transition layer in Comparative Example 1, and the bonding strength of the TiSiN layer / TiN layer / Ti layer gradient transition layer system in Example 2 is the best.

[0077] The above embodiments are merely illustrative of the principles and effects of this patent application and are not intended to limit this patent application. Any person skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of this patent application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this patent application shall still be covered by the claims of this patent application.

Claims

1. A transition layer for silicon carbide ceramic metallization, characterized by, The transition layer for metallization of silicon carbide ceramic is composed of a TiSiN layer, a TiN layer and a Ti layer stacked from bottom to top. In the TiSiN layer, the content of Si is 5at%-30at%.

2. The transition layer for silicon carbide ceramic metallization according to claim 1, characterized in that, The thickness of the TiSiN layer is 180nm-220nm.

3. The transition layer for silicon carbide ceramic metallization according to claim 1, characterized in that, The thickness of the TiN layer is 180nm-220nm.

4. The transition layer for silicon carbide ceramic metallization according to claim 1, characterized by, The thickness of the Ti layer is 80nm-120nm.

5. A method of producing a transition layer for silicon carbide ceramic metallization according to any one of claims 1 to 4, characterized in that The method comprises the following steps: The transition layer for metallization of silicon carbide ceramic is obtained by depositing a TiSiN layer first, then depositing a TiN layer on the TiSiN layer, and finally depositing a Ti layer on the TiN layer by using a magnetron sputtering method.

6. The method of producing a transition layer for silicon carbide ceramic metallization according to claim 5, characterized by, The deposition method of the TiSiN layer is: the air pressure in the vacuum chamber of the magnetron sputtering device is extracted to ≤5×10 -3 After the air pressure in the vacuum chamber is extracted to 0.2 Pa~0.4 Pa, the nitrogen gas and the argon gas with a purity of not less than 99.9% are respectively introduced into the vacuum chamber, the flow ratio of the nitrogen gas to the argon gas is 1~3:5, the Si target and the Ti target are sputtered at the same time, the base bias is-200 V, the power ratio of the Si target to the Ti target is set to 1:1~4 at first, the TiSiN layer is deposited, when the thickness of the TiSiN layer reaches 90 nm~110 nm, the power of the Ti target is fixed, the power ratio of the Si target to the Ti target is uniformly reduced to 0:1~4, and the TiSiN layer reaches the required thickness.

7. The method of claim 5, wherein the transition layer is formed by a process comprising: forming a first layer of a first material on a surface of a silicon carbide substrate; and forming a second layer of a second material on the first layer, the second material being different from the first material. The deposition method of the TiN layer is: the gas pressure in the vacuum chamber of the magnetron sputtering device is extracted to ≤5×10 -3 After the pressure is 0.2 Pa~0.4 Pa, nitrogen gas with a purity of not less than 99.9% and argon gas with a purity of not less than 99.9% are respectively introduced into the vacuum chamber, the flow ratio of the nitrogen gas to the argon gas is 2:5, the Ti target is sputtered under a substrate bias of-60 V, and the TiN layer is deposited on the surface of the TiSiN layer; when the thickness of the TiN layer reaches 90 nm~110 nm, the flow ratio of the nitrogen gas to the argon gas is uniformly reduced from 2:5 to 0:5 at a constant speed until the required thickness of the TiN layer is reached.

8. The method of claim 5, wherein the transition layer is formed by a process comprising: depositing a first layer of a first metal on a surface of a silicon carbide substrate; and depositing a second layer of a second metal on the first layer of the first metal, wherein the first metal and the second metal are different. The deposition method of the Ti layer is: the gas pressure in the vacuum chamber of the magnetron sputtering device is extracted to ≤5×10 -3 After the pressure is adjusted to 0.2 Pa~0.4 Pa, the Ti target is sputtered, the substrate bias is -60 V, and the Ti layer is deposited on the surface of the TiN layer.

9. A silicon carbide ceramic copper clad substrate, characterized by, The copper-clad silicon carbide ceramic substrate is prepared from a silicon carbide ceramic substrate, the transition layer for metallization of silicon carbide ceramic and a copper layer stacked from bottom to top.

10. The method of producing a silicon carbide ceramic copper-clad substrate according to claim 9, wherein The method comprises the following steps: The transition layer for metallization of silicon carbide ceramic is deposited on the silicon carbide ceramic substrate by using a magnetron sputtering method, and then the copper layer is deposited on the transition layer for metallization of silicon carbide ceramic.

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