Apparatus and method for preparing high-purity synthetic quartz ring by CVD method

Abstract

This invention discloses an apparatus and method for preparing high-purity synthetic quartz rings using CVD, comprising a deposition reactor, a burner, a support rod, a central exhaust gas extraction mechanism, and an annular deposition substrate. The support rod has a central hole in its middle and the annular deposition substrate is mounted on its top. An annular groove is provided on the top of the annular deposition substrate, and a rotating lifting mechanism is installed at the bottom of the support rod. The central exhaust gas extraction mechanism includes a central inlet pipe and an extraction pipe sleeved on the central inlet pipe, with the extraction pipe extending into the reaction chamber through the central hole of the support rod and the annular deposition substrate. The burner is installed on the top of the deposition reactor. This invention uses an annular deposition substrate within the deposition reactor, supported by a hollow support rod, and a central exhaust gas extraction mechanism within the hollow support rod to create a central negative pressure, allowing direct deposition of quartz rings on the annular deposition substrate. This solves the problems of complex processes, low material utilization, and high costs associated with processing quartz rings using quartz ingots in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of quartz ring preparation technology, specifically to an apparatus and method for preparing high-purity synthetic quartz rings by CVD. Background Technology

[0002] High-purity synthetic quartz is one of the fundamental materials in the semiconductor industry. The purity requirements for silicon wafers in photovoltaics, panels, and integrated circuits are not on the same order of magnitude. For example, photovoltaics require a purity of 99.9999%, while chip purity requires 99.999999999%. The etching process in integrated circuits is a complex and crucial step in semiconductor manufacturing, a key process in patterning associated with photolithography. High-purity quartz rings are used in this process, and the purity of the quartz ring itself is paramount.

[0003] Currently, conventional methods for preparing quartz rings typically involve either gas refining to melt a cylindrical ingot and then shaping it into a ring, or electrofusion to directly form the ring within a specific mold. Due to the limitations of these processes, the purity levels are generally low, severely restricting the high-end applications of quartz rings. In the industry, high-purity synthetic quartz is mainly prepared through CVD and VAD. CVD, using higher-purity raw materials through high-temperature hydrolysis and melting, results in even higher purity levels. Compared to VAD deposition, CVD deposition produces larger products; therefore, CVD is more suitable for preparing quartz rings with an inner diameter of 300mm or more.

[0004] In existing technologies, the diameter of CVD-deposited ingots is generally 350-800 mm, and they are solid round rods. The fabrication of quartz rings basically involves first drilling the ingot to remove the inner core, and then machining the remaining outer ring into sections according to length, using inner and outer diameters to achieve the desired inner and outer diameter dimensions. This method of fabricating quartz rings is complex, has low material utilization, and results in high production costs. Furthermore, existing technologies also include a process for depositing quartz rings on a support core rod, but this suffers from problems such as contamination of the quartz ring by the support core rod and difficulty in removing the support core rod.

[0005] Therefore, it is of great significance to research and develop a method for preparing quartz rings that has high material utilization, simple process, and low cost. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies by providing an apparatus and method for preparing high-purity synthetic quartz rings using CVD. An annular deposition substrate is set up in the deposition furnace and supported by a hollow support rod. A central exhaust gas extraction mechanism is installed within the hollow support rod to create a central negative pressure, allowing quartz rings to be directly deposited on the annular deposition substrate. This solves the problems of complex processes, low material utilization, and high costs associated with processing quartz rings using quartz ingots in existing technologies.

[0007] To solve the above-mentioned technical problems, the first aspect of the present invention provides an apparatus for preparing high-purity synthetic quartz rings by CVD method, including a deposition reaction furnace, a burner, a support rod, a central exhaust gas extraction mechanism, and an annular deposition substrate;

[0008] The deposition reaction furnace is provided with a reaction chamber, and the bottom of the deposition reaction furnace is provided with an opening;

[0009] The support rod has a central hole in the middle and the annular deposition substrate is installed on the top. The annular deposition substrate has an annular groove on the top and is located in the reaction chamber. A rotating lifting mechanism is installed at the bottom of the support rod.

[0010] The central exhaust gas extraction mechanism includes a central air inlet pipe and an extraction pipe sleeved on the central air inlet pipe. The extraction pipe extends into the reaction chamber through the central hole of the support rod and the annular deposition substrate.

[0011] The burner is mounted on top of the deposition reaction furnace.

[0012] This invention features an annular deposition substrate mounted on top of a hollow support rod within a deposition reactor. A central exhaust gas extraction mechanism is inserted through the hollow support rod. During deposition, the exhaust gas extraction channels around the deposition reactor and the extraction pipe within the support rod work together to remove exhaust gas and particles. Clean, cold air is then introduced through the central air inlet pipe to maintain a central negative pressure. The deposited quartz material is deposited layer by layer onto the annular deposition substrate. As deposition progresses, the material grows gradually, with the growth rate balanced by the retraction of the support rod. The vertical height of the top deposition reaction surface remains constant. The support rod gradually descends to the exhaust gas extraction channel area (low-temperature zone) around the deposition reactor as the material grows. The deposited material solidifies and forms a fixed-size quartz ring. This invention directly deposits quartz rings, eliminating the need for quartz core removal or support rod extraction steps. The process is simple, the product has high purity, and the material utilization rate is high.

[0013] Furthermore, the cross-section of the groove is U-shaped.

[0014] Furthermore, the number of burners is two or more, and the burners are evenly distributed on the top of the deposition reaction furnace. The angle between the axis of the burner and the axis of the deposition reaction furnace is 5°-20°.

[0015] Furthermore, several exhaust gas extraction channels are evenly distributed around the periphery of the deposition reactor.

[0016] Furthermore, the annular deposition substrate has a thickness of 5-15 cm and a top material of quartz.

[0017] Furthermore, the burner is made of quartz; the support rod is made of one or more of the following materials: Al2O3, ZrO, MgO, CaO, carbide ceramics, boride ceramics, nitride ceramics, and silicide ceramics.

[0018] A second aspect of this invention provides a method for preparing high-purity synthetic quartz rings by CVD, using the apparatus described in the first aspect, comprising the following steps:

[0019] S1. Hydrogen and oxygen are introduced into the burner, and after the deposition reaction furnace is heated to the deposition reaction temperature, silicon raw materials are introduced.

[0020] S2. The silicon raw material reacts and melts at high temperature into nano-sized silicon dioxide, which is then deposited into the annular groove at the top of the annular deposition substrate. During the deposition process, air is introduced through the central air inlet pipe and extracted through the air extraction pipe to maintain negative pressure on the upper end of the air extraction pipe.

[0021] S3. The rotating lifting mechanism drives the annular deposition substrate to rotate through the support rod, and as the deposition reaction proceeds and the deposited quartz ring grows, it drives the annular deposition substrate to continuously descend.

[0022] S4. After deposition is complete and the deposition furnace has cooled, the deposited quartz ring is removed to obtain a high-purity synthetic quartz ring.

[0023] Furthermore, in S1, the silicon raw material is high-purity electronic-grade silicon tetrachloride.

[0024] Furthermore, in S2, the negative pressure is -10Pa to -25Pa.

[0025] Furthermore, in S3, during the deposition process, the distance between the upper surface of the deposition quartz ring and the burner remains unchanged; the distance between the top of the central air inlet pipe and the exhaust pipe and the upper surface of the deposition quartz ring also remains unchanged.

[0026] Furthermore, in S3, during the later stage of the deposition reaction, the supply of silicon raw materials is stopped, and after the surface of the material is heated to the point where the top of the deposited quartz ring is flat, the supply of hydrogen and oxygen is stopped.

[0027] Furthermore, the deposition reaction temperature is above 1400°C, and the deposition reaction furnace is cooled to below 80°C.

[0028] Furthermore, in S4, after the deposited quartz ring is removed, the process also includes regularizing the inner and outer circles and cutting.

[0029] The beneficial effects of this invention are:

[0030] The present invention sets up an annular deposition substrate in the deposition reactor chamber and installs it on the top of a hollow support rod. A central exhaust gas extraction mechanism is installed in the hollow support rod. Clean cold air is introduced through the central air inlet pipe and extracted through the exhaust pipe to maintain a central negative pressure. The deposition quartz material is deposited layer by layer onto the annular deposition substrate and condenses to form a fixed-size deposition quartz ring.

[0031] This invention directly deposits quartz rings without the need for quartz weights to remove the inner core or the support rod to be removed. The process is simple, the product has high purity, and the material utilization rate is high. Different sizes of deposition substrates can be adjusted according to the inner diameter of the quartz ring product. The process is simple and has a wide range of applications. Attached Figure Description

[0032] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the apparatus for preparing high-purity synthetic quartz rings by CVD method according to the present invention;

[0034] The labels in the diagram are as follows: 1. Deposition reaction furnace, 2. Burner, 3. Support rod, 4. Central exhaust gas extraction mechanism, 5. Annular deposition substrate, 6. Rotary lifting mechanism, 7. Exhaust gas extraction channel, 8. Deposition quartz ring. Detailed Implementation

[0035] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. 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.

[0036] In this invention, unless otherwise stated, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," indicating orientation or positional relationships, are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. For those skilled in the art, the specific meaning of the above terms in this patent can be understood according to the specific circumstances.

[0037] Reference Figure 1 As shown, this embodiment relates to an apparatus for preparing high-purity synthetic quartz rings by CVD, including a deposition reaction furnace 1, a burner 2, a support rod 3, a central exhaust gas extraction mechanism 4, and an annular deposition substrate 5; the deposition reaction furnace 1 is provided with a reaction chamber, and the bottom of the deposition reaction furnace 1 is provided with an opening; the support rod 3 is provided with a central hole in the middle, and the annular deposition substrate 5 is installed on the top, the annular deposition substrate 5 is provided with an annular groove on the top, the annular deposition substrate 5 is located in the reaction chamber, and a rotation lifting mechanism 6 is installed at the bottom of the support rod 3; the central exhaust gas extraction mechanism 4 includes a central air inlet pipe and an exhaust pipe sleeved on the central air inlet pipe, the exhaust pipe extending into the reaction chamber through the central hole of the support rod 3 and the annular deposition substrate 5; the burner 2 is installed on the top of the deposition reaction furnace 1.

[0038] In this embodiment, an annular deposition substrate 5 with annular grooves is provided in the deposition reactor 1 and installed on the top of a hollow support rod 3. A central exhaust gas extraction mechanism 4 is inserted through the hollow support rod 3. During the deposition process, the exhaust gas extraction channels 7 around the deposition reactor 1 and the extraction pipe in the support rod 3 work together to extract and remove exhaust gas and particles, improving the deposition purity. Clean cold air is then introduced through the central air inlet pipe. The airflow direction within the central exhaust gas extraction mechanism is as follows: Figure 1As indicated by the middle arrow, a central negative pressure is maintained, allowing the deposited quartz material to be deposited layer by layer onto the annular deposition substrate 5, directly forming a deposited quartz ring 8. As deposition progresses, the material gradually grows, with the growth rate balanced by the retraction of the support rod 3. The vertical height of the top deposition reaction surface remains constant. The support rod 3 gradually descends to the exhaust gas channel 7 area (low-temperature zone) around the deposition reaction furnace 1 as the material grows. The deposited material solidifies and forms a fixed-size deposited quartz ring 8. This embodiment directly deposits the quartz ring, eliminating the need for a quartz core removal tool or a support rod removal step. The process is simple, the product purity is high, and the material utilization rate is high. The size of the annular deposition substrate 5 can be adjusted according to the required quartz ring size, making it widely applicable.

[0039] In a preferred embodiment, the groove has a U-shaped cross-section; the annular deposition substrate 5 has a thickness of 5-15 cm and a top material of quartz; the support rod 3 is made of one or more of Al2O3, ZrO, MgO, CaO, carbide ceramics, boride ceramics, nitride ceramics and silicide ceramics.

[0040] In a preferred embodiment, the number of burners 2 is two or more, and the burners 2 are evenly distributed on the top of the deposition reaction furnace 1. The angle between the axis of the burner 2 and the axis of the deposition reaction furnace 1 is 5°-20°. The material of the burner 2 is quartz.

[0041] In a preferred embodiment, several exhaust gas extraction channels 7 are evenly arranged around the periphery of the deposition reactor 1, which together with the exhaust pipe in the support rod 3 to extract exhaust gas and particles and maintain a negative pressure environment.

[0042] Another embodiment provides a method for preparing high-purity synthetic quartz rings by CVD, using the apparatus of the above embodiment, and including the following steps:

[0043] S1. Hydrogen and oxygen are introduced into burner 2. After the deposition reaction furnace 1 is heated to the deposition reaction temperature (1400℃), high-purity electronic-grade silicon tetrachloride raw material is introduced.

[0044] S2. The silicon raw material reacts and melts at high temperature into nano-sized silicon dioxide, which is then deposited into the annular groove at the top of the annular deposition substrate 5. During the deposition process, filtered clean air is introduced into the central air inlet pipe, and air is extracted by the exhaust pipe to maintain a negative pressure environment (-10Pa ~ -25Pa) on the upper end of the exhaust pipe.

[0045] S3. The rotating lifting mechanism 6 drives the annular deposition substrate 5 to rotate through the support rod 3, and as the deposition reaction proceeds and the deposition quartz ring 8 grows, the annular deposition substrate 5 continues to descend.

[0046] S4. After the deposition is completed, and the deposition reaction furnace 1 is cooled to 80°C, the deposited quartz ring 8 is removed to obtain a high-purity synthetic quartz ring.

[0047] In a preferred embodiment, during the deposition process in S3, the distance between the upper surface of the deposition quartz ring 8 and the burner 2 remains unchanged; the distance between the top of the central air inlet pipe and the exhaust pipe and the upper surface of the deposition quartz ring 8 remains unchanged, maintaining a negative pressure from the upper end of the exhaust pipe to the center of the deposition surface. In the later stage of the deposition reaction, the supply of silicon raw materials is stopped, and after the surface of the empty burner reaches a flat top on the upper surface of the deposition quartz ring 8, the supply of hydrogen and oxygen is stopped.

[0048] In a preferred embodiment, after the deposited quartz ring 8 is removed in step S4, the inner and outer circles are regularized to the size of the quartz ring product, and then cut to the height of the quartz ring product.

[0049] In summary, this invention features an annular deposition substrate mounted on top of a hollow support rod within a deposition reactor. A central exhaust gas extraction mechanism is inserted through the hollow support rod, allowing clean, cold air to be introduced through a central inlet pipe and extracted through an exhaust pipe to maintain a central negative pressure. This allows for the deposition of quartz material layer by layer onto the annular deposition substrate, which then solidifies and forms a fixed-size quartz ring. This direct deposition of the quartz ring eliminates the need for removing the inner core using a quartz weight or the support rod, resulting in a simple process, high product purity, and high material utilization. Furthermore, the size of the deposition substrate can be adjusted according to the inner diameter of the quartz ring product, making the process simple and widely applicable.

[0050] The present invention has been described in detail above with reference to specific embodiments and exemplary examples; however, these descriptions should not be construed as limiting the present invention. Those skilled in the art will understand that various equivalent substitutions, modifications, or improvements can be made to the technical solutions and embodiments of the present invention without departing from the spirit and scope of the invention, and all such modifications and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the appended claims.

Claims

1. An apparatus for preparing high-purity synthetic quartz rings by CVD, characterized in that, It includes a deposition reactor, burner, support rod, central exhaust gas extraction mechanism, and annular deposition substrate; The deposition reaction furnace is provided with a reaction chamber, and the bottom of the deposition reaction furnace is provided with an opening; The support rod has a central hole in the middle and the annular deposition substrate is installed on the top. The annular deposition substrate has an annular groove on the top and is located in the reaction chamber. A rotating lifting mechanism is installed at the bottom of the support rod. The central exhaust gas extraction mechanism includes a central air inlet pipe and an extraction pipe sleeved on the central air inlet pipe. The extraction pipe extends into the reaction chamber through the central hole of the support rod and the annular deposition substrate. The burner is mounted on top of the deposition reaction furnace.

2. The apparatus for preparing high-purity synthetic quartz rings by CVD as described in claim 1, characterized in that, The groove has a U-shaped cross-section.

3. The apparatus for preparing high-purity synthetic quartz rings by CVD as described in claim 1, characterized in that, The number of burners is two or more, and the burners are evenly distributed on the top of the deposition reaction furnace. The angle between the axis of the burner and the axis of the deposition reaction furnace is 5°-20°.

4. The apparatus for preparing high-purity synthetic quartz rings by CVD as described in claim 1, characterized in that, Several exhaust gas extraction channels are evenly distributed around the perimeter of the deposition reactor.

5. The apparatus for preparing high-purity synthetic quartz rings by CVD as described in claim 1, characterized in that, The top of the annular deposition substrate is made of quartz.

6. A method for preparing high-purity synthetic quartz rings by CVD, using the apparatus described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Hydrogen and oxygen are introduced into the burner, and after the deposition reaction furnace is heated to the deposition reaction temperature, silicon raw materials are introduced. S2. The silicon raw material reacts and melts at high temperature into nano-sized silicon dioxide, which is then deposited into the annular groove at the top of the annular deposition substrate. During the deposition process, air is introduced through the central air intake pipe and extracted through the extraction pipe to maintain negative pressure on the upper surface of the extraction pipe. S3. The rotating lifting mechanism drives the annular deposition substrate to rotate through the support rod, and as the deposition reaction proceeds and the deposited quartz ring grows, it drives the annular deposition substrate to continuously descend. S4. After deposition is complete and the deposition furnace has cooled, the deposited quartz ring is removed to obtain a high-purity synthetic quartz ring.

7. The method for preparing high-purity synthetic quartz rings by CVD as described in claim 6, characterized in that, In S2, the negative pressure is -10Pa to -25Pa.

8. The method for preparing high-purity synthetic quartz rings by CVD as described in claim 6, characterized in that, In S3, during the deposition process, the distance between the upper surface of the deposition quartz ring and the burner remains unchanged; the distance between the top of the central air inlet pipe and the top of the exhaust pipe and the upper surface of the deposition quartz ring also remains unchanged.

9. The method for preparing high-purity synthetic quartz rings by CVD as described in claim 6, characterized in that, In S3, during the later stage of the deposition reaction, the silicon raw material is stopped being introduced. After the material surface is heated to the point where the top of the deposited quartz ring is flat, the hydrogen and oxygen are stopped being introduced.

10. The method for preparing high-purity synthetic quartz rings by CVD as described in claim 6, characterized in that, In S4, after the deposited quartz ring is removed, the process also includes regularizing the inner and outer circles and cutting.

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