Corrosion furnace suitable for etching treatment of silicon carbide wafer and silicon carbide epitaxial wafer

Abstract

The utility model discloses a kind of etching furnace suitable for silicon carbide wafer and silicon carbide epitaxial sheet etching treatment, including furnace body and furnace cover, furnace cover includes two cover plate halves, the cover plate half includes cover plate base body and the corrosion-resistant plate being set on cover plate base body, corrosion-resistant plate and cover plate base body are detachably connected, first functional layer is set in cover plate base body, and first functional layer is first heat-insulating material layer or hollow heat-insulating layer.The utility model is suitable for silicon carbide wafer and silicon carbide epitaxial sheet etching treatment's etching furnace, by improving and optimizing to furnace cover structure, can promote heat-insulating performance, guarantee the processing quality and production efficiency of silicon carbide wafer and silicon carbide epitaxial sheet.

Description

Technical Field

[0001] This utility model belongs to the field of wafer processing technology. Specifically, this utility model relates to an etching furnace suitable for etching treatment of silicon carbide wafers and silicon carbide epitaxial wafers. Background Technology

[0002] Silicon carbide wafers have advantages such as high thermal conductivity, high breakdown field strength, and high saturated electron drift velocity. Devices made of silicon carbide materials can be used well under harsh conditions such as high temperature, high power, high voltage, high frequency, and high radiation, effectively overcoming the limitations of first-generation silicon material devices.

[0003] In the processing of silicon carbide wafers or silicon carbide epitaxial wafers, an etching furnace is required. The furnace body contains molten etching solution, and a furnace lid is installed on top of the furnace body. During the etching process of silicon carbide wafers or silicon carbide epitaxial wafers, the etching solution needs to be maintained at a high temperature, and the furnace lid seals the opening at the top of the furnace body.

[0004] Therefore, the furnace cover installed on top of the furnace body needs to seal the opening at the top of the furnace to reduce heat loss and maintain a stable temperature inside the furnace. However, the existing furnace cover structure is relatively simple, usually only having a basic sealing function, and has significant defects in heat preservation performance. Due to the poor heat preservation effect, the melting time of the etchant is longer. During the etching process of silicon carbide wafers or silicon carbide epitaxial wafers, a large amount of heat is lost through the furnace cover, making it difficult to maintain the furnace temperature stably within the required high temperature range. This not only prolongs the etching process time and reduces production efficiency, but may also affect the chemical activity and uniformity of the etching solution due to temperature fluctuations, thus adversely affecting the etching quality of silicon carbide wafers or silicon carbide epitaxial wafers.

[0005] Chinese Patent Application No. 202410529186.3 discloses an etching furnace and its control method, belonging to the field of wafer processing. The etching furnace includes a furnace body, a heating device, multiple etching tanks, and a controller. The bottom of the furnace body is provided with multiple positioning slots. The heating device includes an input branch, an output branch, and multiple parallel heating branches. The two ends of the multiple heating branches are respectively connected to the input branch and the output branch. The input branch and the output branch are respectively used to connect to the power supply. Each heating branch is connected in series with a heating resistor, a variable resistor, and an electronic switch. The multiple heating resistors are arranged one-to-one at the bottom of the multiple positioning slots. The multiple etching tanks can be placed one-to-one in the multiple positioning slots to be heated by the corresponding heating resistors. The controller is electrically connected to the multiple variable resistors and the multiple electronic switches at the same time, and is used to control the operating conditions of the multiple variable resistors and the multiple electronic switches according to external commands, so as to control the heating power of the multiple heating resistors.

[0006] This invention provides an etching furnace suitable for etching silicon carbide wafers and silicon carbide epitaxial wafers, with particular emphasis on how to improve heat preservation performance. Utility Model Content

[0007] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention provides an etching furnace suitable for etching silicon carbide wafers and silicon carbide epitaxial wafers, with the purpose of improving heat preservation performance and shortening the processing cycle of silicon carbide wafers and silicon carbide epitaxial wafers.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: an etching furnace suitable for etching treatment of silicon carbide wafers and silicon carbide epitaxial wafers, including a furnace body and a furnace cover, the furnace cover including two cover plate halves, each cover plate half including a cover plate base and a corrosion-resistant plate disposed on the cover plate base, the corrosion-resistant plate and the cover plate base being detachably connected, a first functional layer being disposed in the cover plate base, the first functional layer being a first thermal insulation material layer or a hollow thermal insulation layer.

[0009] The cover plate substrate also includes a second functional layer, and the first functional layer is disposed between the second functional layer and the corrosion-resistant plate.

[0010] The first insulation material layer is made of graphite felt.

[0011] The corrosion-resistant plate is made of nickel.

[0012] The furnace body includes a crucible and a second insulation material layer disposed on the outer surface of the crucible.

[0013] The second insulation material layer is made of graphite felt.

[0014] This invention relates to an etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers. By improving and optimizing the furnace cover structure, the heat preservation performance can be enhanced, ensuring the processing quality and production efficiency of silicon carbide wafers and silicon carbide epitaxial wafers. Attached Figure Description

[0015] This manual includes the following figures, which illustrate the following:

[0016] Figure 1 This is a schematic diagram of the etching furnace of this utility model, applicable to the etching treatment of silicon carbide wafers and silicon carbide epitaxial wafers;

[0017] Figure 2 This is a diagram showing the furnace lid in the open position;

[0018] Figure 3 This is a schematic diagram of the furnace lid in the closed state;

[0019] Figure 4 This is a schematic diagram of the gear transmission mechanism;

[0020] The markings in the diagram are as follows: 1. First functional layer; 2. Second functional layer; 3. Corrosion-resistant plate; 4. Crucible; 5. Second insulation material layer; 6. Half of the cover plate; 7. Temperature measuring hole; 8. Gear; 9. Motor shaft. Detailed Implementation

[0021] The specific embodiments of this utility model will be further described in detail below with reference to the accompanying drawings, in order to help those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of this utility model, and to facilitate its implementation.

[0022] It should be noted that in the following embodiments, the terms "first" and "second" do not represent an absolute distinction in structure and / or function, nor do they represent the order of execution, but are merely for the convenience of description.

[0023] like Figures 1 to 3 As shown, this utility model provides an etching furnace suitable for etching treatment of silicon carbide wafers and silicon carbide epitaxial wafers, including a furnace body and a furnace cover. The furnace cover includes two cover plate halves 6, which have the same structure. Each cover plate half 6 includes a cover plate base and a corrosion-resistant plate 3 disposed on the cover plate base. The corrosion-resistant plate 3 is detachably connected to the cover plate base. A first functional layer 1 is disposed in the cover plate base. The first functional layer 1 is a first thermal insulation material layer or a hollow thermal insulation layer.

[0024] Specifically, such as Figure 1 As shown, the cover plate substrate also includes a second functional layer 2, with a first functional layer 1 disposed between the second functional layer 2 and the corrosion-resistant plate 3. The second functional layer 2 is located at the top of the cover plate substrate and is made of nickel. The corrosion-resistant plate 3 is located at the bottom of the cover plate substrate, facing the inner cavity of the furnace body, which is used to hold the corrosive liquid. The corrosion-resistant plate 3 is also made of nickel. Nickel has good chemical stability and corrosion resistance, effectively resisting the erosion of high-temperature corrosive liquids and extending the service life of the furnace cover. Simultaneously, nickel has a relatively low thermal conductivity, which also helps to improve the heat insulation performance of the furnace cover to some extent.

[0025] Since the corrosion-resistant plate 3 is in direct contact with the high-temperature area of ​​the corrosion furnace, it is designed to be detachably connected to the cover plate base. For example, the corrosion-resistant plate 3 is connected to the cover plate base by bolts, which makes it convenient to disassemble and replace the corrosion-resistant plate 3.

[0026] As the first option, when the first functional layer 1 is the first insulation material layer, the material of the first insulation material layer can be graphite felt, which improves the overall insulation effect of the furnace cover.

[0027] As a second option, when the first functional layer 1 is a hollow insulation layer, a hollow cavity is formed inside the first functional layer 1. This hollow cavity is formed between the second functional layer 2 and the corrosion-resistant plate 3, providing a certain heat preservation effect.

[0028] like Figure 1 As shown, the furnace body includes a crucible 4 and a second insulation material layer 5 disposed on the outer surface of the crucible 4. The crucible 4 is used to hold the corrosive liquid, and the furnace lid is used to seal the top opening of the crucible 4. The second insulation material layer 5 is made of graphite felt and wraps around the outer circular surface of the cylindrical crucible 4 to improve the overall insulation effect of the furnace body.

[0029] like Figure 2 and Figure 3 As shown, the cover plate half 6 has a semi-circular structure. When the furnace lid is closed, the end planes of the two cover plate halves 6 are in contact, and the two cover plate halves 6 are coaxial. The two cover plate halves 6 are connected to the furnace lid opening and closing mechanism, which controls the rotation of the two cover plate halves 6. Figure 4 As shown, the furnace cover opening and closing mechanism mainly includes a drive motor and a gear transmission mechanism. The gear transmission mechanism includes two gears 8, which are fixedly connected to the ends of the two cover plate halves 6 via rotating shafts. The two gears 8 mesh with each other. The motor shaft 9 of the drive motor is coaxially fixedly connected to one of the gears 8. The two gears 8 are rotatably mounted on a bracket, and the drive motor is also mounted on the bracket, which is fixedly mounted on the furnace body. After the drive motor runs, it drives one gear 8 to rotate, which drives the other meshing gear 8 to rotate synchronously. The two gears 8 drive the two cover plate halves 6 to rotate synchronously, but in opposite directions, thus realizing the opening and closing control of the furnace cover.

[0030] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. An etching furnace suitable for etching silicon carbide wafers and silicon carbide epitaxial wafers, comprising a furnace body and a furnace cover, the furnace cover comprising two cover plate halves, characterized in that: The cover plate half includes a cover plate base and a corrosion-resistant plate disposed on the cover plate base. The corrosion-resistant plate and the cover plate base are detachably connected. A first functional layer is disposed in the cover plate base. The first functional layer is a first thermal insulation material layer or a hollow thermal insulation layer.

2. The etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers according to claim 1, characterized in that: The cover plate substrate also includes a second functional layer, and the first functional layer is disposed between the second functional layer and the corrosion-resistant plate.

3. The etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers according to claim 1, characterized in that: The first insulation material layer is made of graphite felt.

4. The etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers according to any one of claims 1 to 3, characterized in that: The corrosion-resistant plate is made of nickel.

5. The etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers according to any one of claims 1 to 3, characterized in that: The furnace body includes a crucible and a second insulation material layer disposed on the outer surface of the crucible.

6. The etching furnace for etching silicon carbide wafers and silicon carbide epitaxial wafers according to claim 5, characterized in that: The second insulation material layer is made of graphite felt.

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