LPCVD heating furnace

Abstract

The application discloses an LPCVD heating furnace body, which comprises a heating furnace, a quartz tube arranged in the heating furnace, a furnace tail sealing ring arranged outside the end of the quartz tube, and a flange structure arranged between the quartz tube and a furnace cover. An airflow guide device is arranged axially inside the end of the quartz tube, the axial length of the airflow guide device covers at least the axial position of the sealing ring, the airflow guide device has an airflow guide channel inside, and the inner end outer wall of the airflow guide device is connected and sealed with the inner wall of the quartz tube at the corresponding position. The hot airflow can pass through the airflow guide channel without directly contacting the position of the sealing ring, so that the working environment of the sealing ring is reduced by about 80-120 DEG C compared with the previous one, and the service life of the sealing ring can be effectively prolonged. In addition, the flange structure adopts an independent cooling water pipe design, the cooling water pipe generating scale can be conveniently disassembled and replaced, and the cooling effect and service life of the flange are avoided from being affected.

Description

Technical Field

[0001] This invention pertains to chemical vapor deposition equipment, specifically to an LPCVD heating furnace. Background Technology

[0002] LPECVD is a low-pressure, high-temperature chemical vapor deposition method used to deposit various functional thin films (mainly Si3N4, SiO2, and polysilicon thin films) on substrates for the fabrication of semiconductor wafer devices. For example... Figure 1 Currently, the heating furnace 1 of the LPCVD system typically operates at 400-800℃. The hot gas flow moves towards the furnace tail of the quartz tube 2 along the vacuum direction. This flow carries heat to the sealing ring 3 at the furnace tail of the quartz tube 2, causing the temperature at this location to be 100-150℃ higher than at the furnace opening. This often leads to the sealing ring 3 rapidly aging and losing its sealing function at the approximately 300℃ environment at the furnace tail. Furthermore, a flange is located between the quartz tube and the furnace cover, and the cooling water pipes for the flange are usually integrated with the flange, making it difficult to clean scale. As the scale thickens, the cooling effect of the flange gradually decreases, thus affecting its service life. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an LPCVD heating furnace body, which effectively improves the service life of the sealing ring by adding an airflow guide pipe near the tail of the furnace so that the hot airflow does not directly contact the location of the sealing ring.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] An LPCVD heating furnace body includes a heating furnace, a quartz tube arranged inside the heating furnace, a furnace tail sealing ring disposed outside the end of the quartz tube, and a flange structure disposed between the quartz tube and the furnace cover. An airflow guiding device is axially provided inside the end of the quartz tube. The axial length of the airflow guiding device at least covers the axial position of the sealing ring. The airflow guiding device has an airflow guiding channel inside and the outer wall of the inner end is connected and sealed to the inner wall of the quartz tube at the corresponding position.

[0006] The airflow guiding device is a straight pipe, and an annular baffle is provided on the outer wall of the inner end of the airflow guiding device, which is connected and sealed to the inner wall of the quartz tube at the corresponding position.

[0007] The axial length of the airflow guide pipe at least covers the axial position where the furnace tail seal ring is located.

[0008] The flange structure includes a first flange and a second flange. The inner end face of the first flange has two raised retaining strips and a circular groove is formed between the two retaining strips. The inner end face of the second flange also has two raised retaining strips. The second flange is interlocked with the retaining strips of the first flange through its retaining strips. The cooling structure also includes a cooling water pipe, which is embedded in the groove.

[0009] The cooling water pipe includes a circular section located within a groove, a cooling water inlet section extending out of the groove, and a cooling water outlet section.

[0010] The outer ring of the groove has a notch for the cooling water inlet section and the cooling water outlet section to pass through.

[0011] The LPCVD heating furnace body of this invention incorporates an airflow guiding device at the end of the quartz tube. This prevents the hot airflow from directly contacting the sealing ring and instead allows it to pass through the airflow guiding channel. This reduces the operating temperature of the sealing ring by approximately 80-120°C, effectively extending its service life. Furthermore, the flange's cooling water pipe is independently designed and installed within the flange groove. If scale buildup occurs inside the pipe and affects cooling performance, the cooling water pipe can be disassembled and replaced separately, saving on maintenance costs. Attached Figure Description

[0012] The invention will now be described in detail with reference to the accompanying drawings and specific embodiments:

[0013] Figure 1 This is an exploded schematic diagram of an existing LPCVD heating furnace body;

[0014] Figure 2 This is a cross-sectional view of an LPCVD heating furnace body according to the present invention;

[0015] Figure 3 This is an exploded view of the flange structure of the present invention;

[0016] Figure 4 This is a cross-sectional schematic diagram of the flange structure of the present invention. Detailed Implementation

[0017] An LPCVD heating furnace body of the present invention, such as Figure 2 As shown, it includes a heating furnace 1, a quartz tube 2 installed inside the heating furnace 1, a furnace tail sealing ring 3 located outside the end of the quartz tube 2, and a flange structure located between the quartz tube 2 and the furnace cover (see...). Figure 3The quartz tube 2 has an axially arranged airflow guiding device 4 at its end. The axial length of the airflow guiding device 4 at least covers the axial position of the sealing ring 3. The airflow guiding device 4 has an airflow guiding channel inside, and its inner end outer wall is connected and sealed to the inner wall of the quartz tube 2 at the corresponding position. In this way, when hot air enters this position, it no longer directly contacts the position of the sealing ring 3 but passes through the airflow guiding channel, thereby reducing the working environment of the sealing ring 3 by about 80-120°C, which can effectively improve the service life of the sealing ring 3.

[0018] The airflow guiding device 4 can be a trumpet-shaped tube, a straight tube, or other similar structures, for example... Figure 2 As shown, the airflow guiding device 4 uses a straight pipe, and its inner end outer wall is provided with an annular baffle that is connected and sealed to the inner wall of the quartz tube 2 at the corresponding position, so as to ensure a better heat insulation and protection effect.

[0019] like Figure 3-4 As shown, the flange structure includes a pair of flanges, specifically a first flange 11 and a second flange 12. The first flange 11 has two raised retaining strips 13a on its inner end face, forming a circular groove 5 between these two strips 13a for mounting its cooling water pipe 7. The second flange 12 also has two raised retaining strips 13b on its inner end face. The second flange 12 connects with the two retaining strips 13a of the first flange 11 via its two retaining strips 13b. Figure 2 The staggered snap-fit ​​shown is as follows: Figure 2 The inner ring retaining strip 13b of the second flange 12 is engaged within the inner ring retaining strip 13a of the first flange 11, while the outer ring retaining strip 13b of the second flange 12 is engaged between the inner and outer ring retaining strips 13a of the first flange 11; the cooling structure also includes a cooling water pipe 7, which is embedded in the groove 5.

[0020] like Figure 3 As shown, the cooling water pipe may specifically include a circular section within the groove 5 and a cooling water inlet section and a cooling water outlet section extending out of the groove 5, with the cooling water inlet section and the cooling water outlet section being parallel to each other. A notch 6 is also provided on the retaining strip 13a on the outer ring of the groove 5 for the cooling water inlet section and the cooling water outlet section to pass through.

[0021] During installation, the circular section of the cooling water pipe 7 is inserted into the groove 5 of the first flange 11, and the cooling water inlet and outlet sections are arranged through the notch 6. Then, the second flange 12 is installed and fixed. After use, if scale forms inside the cooling water pipe 7 and affects the cooling effect, the cooling water pipe 7 can be disassembled and replaced separately, saving maintenance costs.

[0022] However, those skilled in the art should recognize that the above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Any changes or modifications to the above embodiments that are within the essential spirit of the present invention will fall within the scope of the claims of the present invention.

Claims

1. An LPCVD heating furnace body, comprising a heating furnace, a quartz tube disposed within the heating furnace, a furnace tail sealing ring disposed outside the end of the quartz tube, and a flange structure disposed between the quartz tube and the furnace cover, characterized in that: An airflow guiding device is provided axially inside the end of the quartz tube. The axial length of the airflow guiding device covers at least the axial position where the sealing ring is located and has a guide tube section with a diameter smaller than that of the quartz tube. The guide tube section is spaced apart from the quartz tube section where the sealing ring is located. The airflow guiding device has an airflow guiding channel inside and the outer wall of the inner end is connected and sealed to the inner wall of the quartz tube at the corresponding position.

2. The LPCVD heating furnace according to claim 1, wherein: The airflow guiding device is a straight pipe, and an annular baffle is provided on the outer wall of the inner end of the airflow guiding device, which is connected and sealed to the inner wall of the quartz tube at the corresponding position.

3. The LPCVD heating furnace according to claim 2, wherein: The axial length of the straight pipe of the airflow guiding device at least covers the axial position of the furnace tail sealing ring.

4. The LPCVD heating furnace body according to claim 1, characterized in that: The flange structure includes a first flange and a second flange. The inner end face of the first flange has two raised retaining strips and a circular groove is formed between the two retaining strips. The inner end face of the second flange also has two raised retaining strips. The second flange is interlocked with the retaining strips of the first flange through its retaining strips. The cooling structure includes a cooling water pipe, which is embedded in the groove.

5. An LPCVD heating furnace body according to claim 4, characterized in that: The cooling water pipe includes a circular section located within a groove, a cooling water inlet section extending out of the groove, and a cooling water outlet section.

6. The LPCVD heating furnace body according to claim 5, characterized in that: The outer ring of the groove has a notch for the cooling water inlet section and the cooling water outlet section to pass through.

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