Method for manufacturing silicon carbide device through blue film and laser technology

Abstract

The invention relates to the technical field of silicon carbide devices, and discloses a method for manufacturing a silicon carbide device through a blue film and a laser technology, which comprises the following steps of: attaching a layer of blue film (2) on a silicon carbide substrate (1); cutting the blue film (2) through a laser technology to enable the blue film (2) to form a target pattern on the silicon carbide substrate (1); electroplating and depositing a metal layer (3) on the surfaces of the silicon carbide substrate (1) and the blue film (2) obtained in the step (2); and stripping the blue film (2) and the metal layer (3) on the blue film (2) to obtain the metal layer (3) deposited on the surface of the silicon carbide substrate (1). According to the method, expensive equipment such as a photoetching machine and a gluing developing machine and consumables such as high-purity photoresist, developing liquid and photoresist removing liquid are omitted, so that the cost can be effectively saved; the process period is shortened by more than 30%, and the cost and yield loss risk of the clean room are reduced.

Description

Technical Field

[0001] This invention relates to the field of silicon carbide technology, and in particular to a method for manufacturing silicon carbide devices using blue film and laser technology. Background Technology

[0002] In current integrated circuit and micro / nano device manufacturing, mainstream metal electrode fabrication technologies (such as etching-based patterning processes or traditional lift-off processes) all rely on the core process chain of photolithography-development-etching / stripping. The complexity and high cost of these processes are particularly prominent in high-precision, large-scale mass production scenarios.

[0003] Specifically, the complete process involves several precisely controlled steps: First, a photoresist is uniformly coated onto the substrate surface using a coating machine (positive or negative photoresist is selected based on precision requirements, and the film thickness must be controlled precisely to the nanometer level to adapt to the subsequent pattern resolution); then, exposure is performed using a stepper lithography machine, using ultraviolet or deep ultraviolet (DUV) light to transfer the electrode pattern on the mask to the photoresist layer. This process requires strict control of the exposure dose, focal length, and alignment accuracy (in advanced processes, the alignment error must be less than 1nm) to avoid pattern distortion; after exposure, the development stage begins, using a developer (such as TMAH solution) to dissolve the unexposed or exposed photoresist areas, forming a photoresist mask complementary to the target electrode. Even slight fluctuations in development time, temperature, and developer concentration can lead to increased edge roughness or dimensional deviations in the pattern; after metal deposition (such as sputtering, evaporation, or electroplating), residual photoresist must be removed through a photoresist stripping process (wet solvent dissolution or dry plasma ashing). Incomplete photoresist stripping can lead to poor electrode contact, while excessive photoresist stripping may damage the substrate or metal layer.

[0004] From a cost and efficiency perspective, the resource investment in this process grows exponentially: In terms of core equipment, a single advanced DUV lithography machine costs over ten million US dollars, and the cost of supporting equipment such as coating and developing machines and plasma etching machines also reaches several million US dollars per unit. Furthermore, it requires a constant temperature and humidity, ultra-clean (Class 1) factory environment, resulting in huge initial fixed asset investment. In terms of materials, the purity requirements for chemicals such as photoresist (especially deep ultraviolet photoresist), developer, and resist remover are extremely high (metal ion impurities must be below ppb), and the consumption increases significantly with wafer size (e.g., 12-inch wafers), with the cost of lithography-related materials per wafer reaching tens of US dollars. In addition, the complexity of the process directly leads to extended process cycles (single batch processing takes several hours), and yield losses at each stage accumulate and amplify (e.g., lithography alignment errors, developing defects, etc., can all lead to the scrapping of the entire batch of wafers), further increasing manufacturing costs. This "high investment-long cycle-high risk" characteristic has become a significant obstacle to technology implementation in small-batch device development or low-cost application scenarios (such as some sensors and power devices). For example, patent number 202210282247.1, patent title is "Manufacturing Method of Silicon Carbide Device", which is similar to the method described above.

[0005] To address the above shortcomings, this process replaces the coating, exposure, and development process with laser and blue film removal of unwanted graphic areas during the coating stage. Subsequently, film peeling replaces the adhesive removal process, aiming to shorten the process flow, reduce costs, and improve efficiency. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing a method for manufacturing silicon carbide devices using blue film and laser technology.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for manufacturing silicon carbide devices using blue film and laser technology includes the following steps: 1) A blue film is laminated onto a silicon carbide substrate; 2) The blue film is cut using laser technology to form the target pattern on the silicon carbide substrate; 3) Electroplating and depositing a metal layer on the silicon carbide substrate and blue film obtained in step 2); 4) Peel off the blue film and the metal layer on it to obtain the metal layer deposited on the surface of the silicon carbide substrate. The final metal layer is the inverse of the target pattern in step 2).

[0008] Preferably, the silicon carbide substrate is pretreated before step 1). Step 1) specifically includes the following steps: stretching the blue film and fixing it in the metal ring frame, fixing the silicon carbide substrate by vacuum adsorption equipment (film attaching machine), and uniformly attaching the blue film to the silicon carbide substrate by the metal ring frame.

[0009] Preferably, step 1) further includes the following steps: after the blue film is bonded to the silicon carbide substrate, it is subjected to low-temperature heating treatment at a temperature of 60-80℃ for 2-20 minutes. Heating results in a more stable film state and better wafer fixation. Heating and curing are performed in a dedicated oven with uniform temperature distribution.

[0010] Preferably, the blue film is a polymer film with a thickness of 40-80 μm and an adhesive peel strength typically of 0.5-1.2 N / 25 mm.

[0011] As a preferred option, the blue film is chip cutting blue film, also known as electronic grade tape. Blue film is a release film with a PVC base and PET inserts, possessing excellent adhesion and high-temperature resistance.

[0012] Preferably, the laser cutting in step 2) uses a 355nm ultraviolet nanosecond laser; the laser pulse width is 20-50ns; the pulse frequency is 30-80kHz; the average power is 3-5W; and the cutting speed is 500-800mm / s.

[0013] Preferably, the metal layer is a copper metal layer; a metal seed layer (31) for depositing metal is first attached before step 3).

[0014] Preferably, in step 4), the blue film and its metal layer are peeled off using a special adhesive tape. The metal layer on the blue film itself needs to be removed and does not need to form a strong adhesion with the blue film. If there is any residue after the first peeling, the adhesive tape can be used to peel the film again. The adhesive tape is PET tape with a viscosity of 12-18 g / in. The composition of the adhesive tape is similar to that of the blue film, which can firmly stick to the edge of the blue film, assist in manual peeling, and is not easy to break.

[0015] Preferably, after step 4) is completed, check whether there is any adhesive residue on the surface of the silicon carbide substrate. If so, gently wipe it with semiconductor-grade isopropyl alcohol (IPA) and a lint-free cloth.

[0016] The present invention has significant technical advantages due to the adoption of the above technical solutions: the laser equipment used in this application has a relatively low cost, eliminating the need for expensive equipment such as lithography machines, coating and developing machines, as well as consumables such as high-purity photoresist, developing solution, and resist remover; secondly, the cost of blue film material is only 1 / 10 to 1 / 5 of that of photoresist of the same area, and the investment in laser cutting equipment is much lower than that of lithography systems; in addition, the process flow of this application is reduced compared to the prior art, from the original coating, exposure, developing, dry or wet resist removal, etc., to three main steps: film application, laser hole drilling, and film peeling, shortening the process cycle by more than 30% and reducing cleanroom costs and the risk of yield loss. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention.

[0018] The parts referred to by the numbers in the attached figure are as follows: 1—Silicon carbide substrate, 2—Blue film, 3—Metal layer, 4—Adhesive tape, 31—Metal seed layer. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0020] Example 1 A method for manufacturing silicon carbide devices using blue film and laser technology, as shown in the figure, includes the following steps: 1) A blue film 2 is laminated onto a silicon carbide substrate 1; 2) The blue film 2 is cut using laser technology to form the target pattern on the silicon carbide substrate 1; 3) Electroplating and depositing a metal layer 3 on the surfaces of the silicon carbide substrate 1 and the blue film 2 obtained in step 2); 4) Peel off the blue film 2 and the metal layer 3 on it to obtain the metal layer 3 deposited on the surface of the silicon carbide substrate 1. The final metal layer 3 is the inverse of the target pattern in step 2).

[0021] Example 2 Similar to Example 1, except that the silicon carbide substrate 1 is pretreated before step 1). Step 1) specifically includes the following steps: stretching the blue film 2 and fixing it in a metal ring frame; fixing the silicon carbide substrate 1 using a vacuum adsorption device (film laminator); and uniformly attaching the blue film 2 to the silicon carbide substrate 1 using the metal ring frame. The metal ring frame facilitates both the film lamination operation and subsequent placement in the dicing machine. The blue film 2 must maintain uniform tension during stretching to avoid loosening or wrinkling. A dedicated film laminator is used to gently hold the thinned silicon carbide substrate 1 and then accurately press it onto the center of the blue film 2, ensuring that the silicon carbide substrate 1 is flatly adhered to the blue film 2. During the operation, air bubbles or particles should be avoided to prevent affecting the subsequent dicing quality. The film laminator fixes the silicon carbide substrate 1 through a vacuum adsorption system, thereby applying uniform pressure during film lamination.

[0022] Step 1) specifically includes the following steps: After the blue film 2 is bonded to the silicon carbide substrate 1, they are subjected to low-temperature heating treatment at 70°C for 12 minutes. Heating results in a more stable film state and better wafer fixation. Heating and curing are performed in a dedicated oven with uniform temperature distribution.

[0023] Example 3 Similar to Example 1, except that the blue film 2 is a polymer film with a thickness of 60 μm and an adhesive peel strength of typically 0.8 N / 25 mm.

[0024] Blue Film 2 is a chip cutting blue film, also known as electronic grade tape. Blue Film 2 is a release film with PVC as the base material and PET reinforcement, which has good adhesion and high temperature resistance.

[0025] Example 4 Similar to Example 1, except that the laser cutting in step 2) uses a 355nm ultraviolet nanosecond laser; the laser pulse width is 35ns; the pulse frequency is 55kHz; the average power is 4W; and the cutting speed is 650mm / s.

[0026] Example 5 Similar to Example 1, except that the metal layer 3 is a copper metal layer. Before step 3), a metal seed layer 31 for depositing metal is first attached to the surface of the silicon carbide substrate 1 and the blue film 2.

[0027] Example 6 Similar to Example 1, except that in step 4), the special auxiliary adhesive tape 4 is used to peel off the blue film 2 and the metal layer 3 on it. The metal layer 3 on the blue film 2 needs to be removed itself and does not need to form a strong adhesion with the blue film 2. If there is any residue after the first peeling, the adhesive tape 4 can be used to peel the film again. The adhesive tape 4 is a PET tape with an adhesiveness of 16g / in. The composition of the adhesive tape 4 is similar to that of the blue film 2. It can firmly stick to the edge of the blue film, assist in manual peeling, and is not easy to break.

[0028] Example 7 Similar to Example 1, except that after step 4) is completed, check whether there is any adhesive residue on the surface of the silicon carbide substrate 1. If so, gently wipe it with semiconductor grade isopropyl alcohol (IPA) and a lint-free cloth.

[0029] In summary, the above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention should be covered by the present invention.

Claims

1. A method of fabricating a silicon carbide device by means of a blue tape and laser technology, characterized by: The method comprises the following steps: 1) attaching a layer of blue film (2) to a silicon carbide substrate (1); 2) cutting the blue film (2) by laser technology to form a target pattern on the silicon carbide substrate (1); 3) electroplating and depositing a metal layer (3) on the surface of the silicon carbide substrate (1) and the blue film (2) obtained in step 2); 4) peeling off the blue film (2) and the metal layer (3) thereon to obtain the metal layer (3) deposited on the surface of the silicon carbide substrate (1).

2. The method for manufacturing silicon carbide devices using blue film and laser technology according to claim 1, characterized in that: Step 1) specifically comprises the following steps: stretching the blue film (2) and fixing it in a metal ring frame, fixing the silicon carbide substrate (1) by a vacuum suction device, and uniformly attaching the blue film (2) to the silicon carbide substrate (1) through the metal ring frame.

3. The method of any one of claims 1 or 2 for fabricating a silicon carbide device by a blue tape and laser technique, characterized in that: Step 1) specifically further comprises the following steps: after the blue film (2) is attached to the silicon carbide substrate (1), it is heated together at a low temperature, the temperature is 60-80℃, and the heating time is 2-20 minutes.

4. The method for manufacturing silicon carbide devices using blue film and laser technology according to claim 1, characterized in that: The blue film (2) is a polymer film with a thickness of 40-80um, and the adhesive peel strength is usually 0.5-1.2N / 25mm.

5. The method of any one of claims 1 or 4, wherein: The blue film (2) is a release film made of PVC as the base material and equipped with PET.

6. The method of claim 1, wherein: the method further comprises: forming a plurality of trenches in the substrate; and forming a plurality of trenches in the substrate. The laser cutting in step 2) uses a 355nm ultraviolet nanosecond laser; the laser pulse width is 20-50ns; the pulse frequency is 30-80kHz; the average power is 3-5W; and the cutting speed is 500-800mm / s.

7. The method for manufacturing silicon carbide devices using blue film and laser technology according to claim 1, characterized in that: The metal layer (3) is a copper metal layer; before step 3), a metal seed layer (31) for depositing metal is first attached.

8. The method for manufacturing silicon carbide devices using blue film and laser technology according to claim 1, characterized in that: In step 4), the blue film (2) and the metal layer (3) thereon are peeled off by adhesive tape (4); the adhesive tape (4) is a PET tape with a tackiness of 12-18g / in.

9. The method for manufacturing silicon carbide devices using blue film and laser technology according to claim 1, characterized in that: After step 4) is completed, check whether there is glue residue on the surface of the silicon carbide substrate (1), if there is, wipe it off with semiconductor-grade isopropyl alcohol and a dust-free cloth.

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