Method for joining silicon components using silicon powder and a high-frequency heating device

Abstract

The present invention relates to a method for joining silicon parts using silicon powder and a high frequency heating device, and is characterized by including the steps of forming a bonding concavo-convex structure on a joining surface of a lower ring and an upper ring; assembling the lower ring and the upper ring in a silicon part joining device; putting single crystal silicon powder into the bonding concavo-convex structure of the joining surface of the lower ring and the upper ring; and heating to fuse the joining surface between the lower ring and the upper ring, and has the advantage that the quality of etching and film formation can be improved by fusing and bonding the silicon parts using the silicon powder of the assembly structure and the high frequency heating device.

Description

Technical Field

[0001] This invention relates to a method for bonding silicon components using silicon powder and a high-frequency heating device. Background Technology

[0002] Typically, semiconductor devices are manufactured by forming a semiconductor thin film, conductive thin film, or insulating thin film on a semiconductor substrate (i.e., a silicon wafer) and etching a portion of it.

[0003] Plasma technology will be used during the thin film formation and etching processes. For example, in the etching process, the reactive gas is placed in an excited plasma state by supplying reactive gas to the plasma etching chamber and applying a high-frequency power supply to the chamber.

[0004] In this semiconductor manufacturing process, in order to improve etching efficiency and film formation efficiency, various silicon components are used in the cavity to support the wafer and uniformly distribute plasma, introduce and expel introduced gases, etc.

[0005] In particular, as one of the silicon components, the C-ring disclosed in Korean Utility Model Publication No. 20-0478935 is a consumable silicon component. When the groove is processed, advanced equipment or advanced technology such as laser or discharge is required. Since the groove processing part is floating in the air and there is no separate fixing device, it is difficult to fix it stably. For silicon, which is brittle, the following problems exist: the groove part is easy to break, resulting in low processing yield and large material loss.

[0006] To improve this problem, Korean Patent Nos. 10-2102132 and 10-2040281 and Korean Utility Model No. 20-0491165 disclose methods for manufacturing an upper ring and a lower ring separately and for joining them together by means of a third connecting part or threaded connection.

[0007] However, these assembled structures are structurally complex, and microparticles are generated at the joints between components, resulting in problems such as poor etching and film quality. Summary of the Invention

[0008] The present invention addresses the problems of the prior art as described above, and aims to provide a method for bonding silicon components using silicon powder and a high-frequency heating device. Specifically, silicon components can be fused together using silicon powder and a high-frequency heating device in the assembly structure, thereby simplifying the structure and improving the quality of etching and film formation.

[0009] To achieve the above objectives, the bonding method for silicon components using silicon powder and a high-frequency heating device of the present invention is characterized by comprising the following steps: forming a bonding uneven structure on the bonding surface of a lower ring and an upper ring; assembling the lower ring and the upper ring into a silicon component bonding device; placing single-crystal silicon powder into the bonding uneven structure on the bonding surface of the lower ring and the upper ring; and heating and fusing the bonding surface between the lower ring and the upper ring.

[0010] The present invention is characterized in that, in the step of forming a joint concave-convex structure on the mating surface of the lower ring and the upper ring, a protrusion is formed on the lower surface of the upper ring and a groove is formed on the upper surface of the lower ring to engage with the protrusion.

[0011] The invention is characterized in that the groove is a circular groove, which is symmetrical about the center circumference of the upper surface of the lower ring and is formed on the overall width of the upper surface of the lower ring.

[0012] The invention is characterized in that, in the groove, the deepest point formed from the upper surface of the lower ring is 3mm to 5mm, and the length of the same depth in the width direction of the upper surface of the lower ring at the deepest point reaches within 70% of the total width of the upper surface of the lower ring.

[0013] The invention is characterized in that a positioning upper protrusion is formed on the bottom surface of the upper ring and a positioning lower groove is formed on a portion of the upper surface of the lower ring to engage with the positioning upper protrusion of the upper ring. The positioning lower groove is formed between the outer center line and the outer circumference line between the center circumference line and the outer circumference line of the lower ring, or between the inner center line and the inner circumference line between the center circumference line and the inner circumference line of the lower ring.

[0014] The present invention is characterized in that the lower positioning groove is a hemispherical groove.

[0015] The present invention is characterized in that, between the upper ring and the lower ring, silicon powder, which serves as a welding agent, is first filled into the welding portion, and then the upper ring and the lower ring are respectively assembled to the upper fixing device and the lower fixing device of the silicon component bonding device made of molybdenum.

[0016] The present invention is characterized in that the step of heating and welding the joint surface between the lower ring and the upper ring includes the following steps: forming a vacuum atmosphere to 90 to 110 torr; maintaining the vacuum level at 50 to 70 torr by introducing argon gas; applying pressure between the assembled upper ring and lower ring by using an upper fixing device and a lower fixing device; increasing the atmosphere temperature of the vacuum furnace with the crucible by operating an upper heater and a lower heater; locally heating the welded portion of the joint surface by operating a side heater capable of high-frequency induction heating; and cooling the welded portion.

[0017] The present invention is characterized in that, by operating a side heater capable of high-frequency induction heating, the temperature of the molten weld portion is kept within the range of 1500°C to 1600°C.

[0018] The present invention is characterized in that, in the step of cooling the above-mentioned welded part, after the welded part is melted, the power supply of the side heater that can realize high-frequency induction heating is cut off, so that the temperature of the above-mentioned upper heater and lower heater drops to 1400°C, 1200°C, 1000°C, 900°C, 700°C, 500°C and 300°C respectively, and is maintained in each range for 10 to 20 minutes.

[0019] According to the structure described above, the present invention is characterized by including the following steps: forming a bonding uneven structure on the mating surface of the lower ring and the upper ring; assembling the lower ring and the upper ring on a silicon component bonding device; placing single-crystal silicon powder into the bonding uneven structure on the mating surface of the lower ring and the upper ring; and heating and fusing the mating surface between the lower ring and the upper ring. Therefore, it has the advantage that the quality of etching and film formation can be improved through a simple structure. Attached Figure Description

[0020] Figure 1 A front cross-sectional view showing a device that uses silicon powder and a high-frequency heating device to fuse silicon components together.

[0021] Figure 2 A perspective view showing the structure of a C-ring as an example of a silicon component.

[0022] Figure 3 To show in Figure 2 A cross-sectional view of an example of the interlocking convex and concave structure of the lower and upper rings in a C-ring, as observed from the cross-section.

[0023] Figure 4 To show in Figure 2 A cross-sectional view of another example of the interlocking convex and concave structure of the lower and upper rings in the C-ring, observed from the cross-section. Detailed Implementation

[0024] Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the method for welding silicon components using silicon powder and a high-frequency heating device according to the present invention will be described in detail.

[0025] Typically, in semiconductor manufacturing processes such as plasma processing chambers, silicon components are used in etching equipment. These components are typically made of one of the following materials: single-crystal silicon (SCI), polycrystalline silicon (PolySi), sapphire, yttrium oxide (Y₂O₃), silicon carbide (SiC), quartz, silicon nitride (Si₃N₄), zirconium dioxide (ZrO₂), single-crystal carbon, or polycrystalline carbon (C). They are consumable components, as illustrated in Korean Utility Model Publication No. 20-0478935. Figure 1 The confinement ring (hereinafter referred to as "C-ring") of the plasma treatment chamber, etc.

[0026] For ease of explanation, the present invention will be described in terms of the bonding method of the C-ring. However, it is obvious that the silicon component of the present invention is not limited to the C-ring, and the device using the silicon component is not limited to the plasma processing chamber.

[0027] First, the device of the present invention, which uses silicon powder and a high-frequency heating device to fuse and combine the C-ring, can be implemented by modifying and using equipment very similar to the silicon ingot manufacturing apparatus for producing silicon ingots disclosed in Korean Patent No. 10-0916843 and Korean Patent No. 10-2011-0038040, etc. It can utilize technologies related to the heating device, cooling device, control of the heating and cooling device, and the fixing structure of the crucible, etc., so detailed descriptions are omitted.

[0028] However, in order to easily understand the present invention, in Figure 1 The diagram shows the entire structure of a device that uses silicon powder and a high-frequency heating device to fuse silicon components together.

[0029] like Figure 1 As shown, the vacuum furnace 10 includes: a crucible 80, which forms a structure capable of housing a silicon component A to be bonded (equivalent to...). Figure 2 The exemplary component C ring (the upper ring) and silicon component B (equivalent to Figure 2 The exemplary component C includes the space of the lower ring of the ring; a side heater 50 capable of high-frequency induction heating for heating silicon component A and silicon component B; a water-cooled resistance heating upper heater 60 and a water-cooled resistance heating lower heater 70; a molybdenum lower fixing device 20 for fixing silicon component B; and a molybdenum upper fixing device 30 for fixing silicon component A and moving it up and down under pressure.

[0030] The upper heater 60 of the water-cooled resistance heating method described above can be configured such that the resistance heating wire of the carbon resistance heater or the like embedded in the upper fixing device 30 is embedded, or it can be configured such that the lower heater 70 is embedded in the carbon resistance heater or the like of the lower fixing device 20 made of molybdenum material that can be fixedly mounted to the silicon component B.

[0031] Moreover, it is obvious that additional heating devices, cooling water supply pumps, vacuum maintenance devices, temperature control devices, and argon (Ar) atmosphere maintenance intake and exhaust devices can be provided for silicon ingot manufacturing apparatus or etching film forming apparatus (not shown).

[0032] The following describes the steps for welding silicon components using silicon powder and a high-frequency heating device (refer to Korean Patent Publication No. 10-2016-0001838).

[0033] For ease of explanation, the following description will assume that the upper ring of the C-ring (confinement ring, also known as the confinement ring) of one of the silicon components to be fused is silicon component A, and the lower ring is silicon component B. That is, in Figure 2 In the C-ring, the part with the gap is called the upper ring, but this is just for the sake of explanation, so it is also fine to call the part with the gap in the C-ring the lower ring.

[0034] In step 1, the silicon disk is prepared in the upper ring manufacturing step by the confinement ring (C-ring) disclosed in Korean Utility Model No. 10-0478935 or the sawing process disclosed in Korean Patent No. 10-2102132.

[0035] Silicon rings are formed by performing a core drilling (or core extraction) process that creates a through hole in a silicon disk.

[0036] The inner and outer diameters of the cored silicon ring are machined using a grinding machine or machining center (MCT), and additional processes are performed using an electrical discharge machining (EDM) machine and by forming silicon components with various holes.

[0037] In step 2, the lower ring manufacturing step will be performed using the same method as the manufacturing method of the limiting ring in Korean Utility Model No. 10-0478935 or Korean Patent No. 10-2102132.

[0038] More specifically, a silicon ring is formed by performing a core-taking process to form a through hole in a silicon disk, which is prepared to be cut by a sawing process.

[0039] Furthermore, additional processes are performed by machining the inner and outer diameters of the cored silicon ring using a grinding machine or machining center, and by using an electrical discharge machining (EDM) machine to form silicon components with various holes.

[0040] Step 3 is a process for forming a joint uneven structure on the mating surface of the lower ring and the upper ring. First, a groove is formed on the upper surface of the lower ring that contacts the upper ring, which can be filled with single crystal silicon powder and is combined with the protrusion formed on the lower surface of the upper ring described later.

[0041] The aforementioned groove is a circular groove, which is symmetrical about the center circumference (virtual circumference) of the upper surface of the lower ring and is formed on the upper surface of the lower ring with an overall width that forms on the entire upper surface of the lower ring.

[0042] Furthermore, preferably, the deepest point formed in the groove from the upper surface of the lower ring is 3mm to 5mm, and the length of the same depth in the width direction of the upper surface of the lower ring at the deepest point reaches within 70% of the total width of the upper surface of the lower ring.

[0043] Furthermore, in order to achieve positioning when combined with the upper ring described later, a positioning lower groove is formed in a portion of the groove.

[0044] Specifically, such as Figure 3 and Figure 4 As shown, a positioning upper protrusion is formed on the bottom surface of the upper ring, and a positioning lower groove is formed on a portion of the upper surface of the lower ring to engage with the positioning upper protrusion of the upper ring. The positioning lower groove can be formed between the outer center line and the outer circumference line between the center circumference line and the outer circumference line of the lower ring, or between the inner center line and the inner circumference line between the center circumference line and the inner circumference line of the lower ring.

[0045] In the center circumference of the upper surface of the lower ring, one or two positioning grooves can be formed on the outer or inner side of the upper surface of the lower ring. Considering mechanical strength, the appropriate position is the midpoint between the center circumference and the outer circumference of the upper surface of the lower ring, or the midpoint between the center circumference and the inner circumference of the upper surface of the lower ring.

[0046] Furthermore, the aforementioned positioning lower groove is a hemispherical groove with a maximum protrusion height of approximately 1 mm and a maximum diameter of 1 mm.

[0047] The positioning lower groove can be machined using a grinding machine or machining center, or by electrical discharge machining, or by etching.

[0048] In step 4, the lower ring and the upper ring are assembled. Figure 1 The silicon component bonding device shown.

[0049] However, in this step, silicon powder, which serves as a welding agent, is first filled into the welding part between the lower ring and the upper ring. Then, the lower ring and the upper ring can be assembled into the upper molybdenum fixing device 30 and the lower molybdenum fixing device 20 of the silicon component bonding device.

[0050] Furthermore, although the assembly part for assembling the upper ring and the lower ring onto the upper fixing device 30 and the lower fixing device 20 made of molybdenum is not shown, a simple flat plate shape can be formed according to the shape of the silicon component by using mechanical component fixing devices commonly used in the art.

[0051] Regardless of the structure, any structure that can be fixed during the welding process of silicon components is acceptable.

[0052] In step 5, monocrystalline silicon powder is placed into the joint surface of the lower ring and the upper ring, and melted between the joint surfaces of the lower ring and the upper ring. Monocrystalline silicon powder is also placed into the joint surface of the lower ring and the upper ring as a molten binder for bonding the upper ring and the lower ring.

[0053] The amount of crystalline silicon powder added varies depending on the size of the lower and upper rings. However, it is preferable to form a 3mm molten section when the lower and upper rings are bonded together by melting the monocrystalline silicon powder, taking into account mechanical strength and the efficiency of subsequent welding surface processing. For example, the molten thickness based on the monocrystalline silicon powder accounts for 70%, and the molten thickness of the bonding surface between the upper and lower rings accounts for 30%.

[0054] However, this can vary depending on the size of the silicon component, the characteristics of the material, and the shape of the interface, and is therefore not limited to this.

[0055] Step 6 is the joint surface heating and welding step, that is, filling the space between the upper ring and the lower ring with molten silicon powder, assembling it into the welding equipment of the silicon component, and then welding the upper ring and the lower ring by heating and cooling.

[0056] Specifically, this step can be further subdivided into the following steps.

[0057] In step 6-1, a vacuum pump of the silicon component welding equipment is used to achieve a vacuum atmosphere of 90 torr to 110 torr.

[0058] In step 6-2, the vacuum level is maintained at 50 Torr to 70 Torr by introducing argon gas.

[0059] In step 6-3, pressure is applied between the assembled upper ring and lower ring by using the upper fixing device 30 and the lower fixing device 20.

[0060] If the welded portion is heated and cooled by the side heater 50 that enables high-frequency induction heating, the silicon in the welded portion will expand. Therefore, in order to control and suppress this, the steps described above are performed. The applied pressure can vary depending on the size of the product, especially depending on the thickness of the welded portion.

[0061] As an example, if a C-ring is used and the thickness of the mating surface reaches 6mm to 7mm, the applied pressure is 1kg / cm². 2 For silicon components used in semiconductor devices, a pressure of 0.5 kg / cm is typically applied. 2 ~5kg / cm 2 Pressure within a range.

[0062] In step 6-4, the atmosphere temperature of the vacuum furnace 10 containing the crucible is raised to 1300°C by operating the upper heater 60 and the lower heater 70.

[0063] In this case, due to the characteristics of silicon, if a thermal shock of more than 300°C is generated instantaneously, cracks will be generated. Therefore, in a vacuum atmosphere of 90 torr (maintained by a constant supply of argon gas), the upper heater 60 and the lower heater 70, which are used to heat the atmosphere inside the vacuum chamber (carbon resistance heater), are heated to 300°C and maintained for 30 minutes, respectively. Then, the temperature is raised to 1180°C and maintained for 30 minutes.

[0064] In this case, the atmosphere temperature is raised to 1420°C by a heater, and the atmosphere temperature of the vacuum furnace 10 is maintained at 1300°C.

[0065] For step 6-5, this step is to locally heat the welded part by operating the side heater 50, which is capable of high-frequency induction heating.

[0066] Specifically, the side heater 50, which is capable of high-frequency induction heating, is first heated to 1550°C, which allows the welded part to melt. Under these conditions, the heating temperature is gradually increased in a manner that does not generate thermal shock.

[0067] In this case, the temperature may vary depending on the thickness and shape of the silicon component, but the minimum temperature is about 1500°C, the maximum temperature is about 1600°C, and the most preferred temperature is 1550°C.

[0068] If the heating temperature is below 1500°C, the powder will be partially melted, making bonding impossible; if the temperature is above 1600°C, the weld surface of the parts will collapse.

[0069] For step 6-6, this step is the cooling step of the welded part. After the welded part is melted at a temperature of 1550°C, the power supply of the side heater 50, which can realize high-frequency induction heating, is cut off. The temperature of the upper heater 60 and the lower heater 70 is controlled to decrease step by step at temperatures of 1400°C, 1200°C, 1000°C, 900°C, 700°C, 500°C, 300°C, and 100°C, and is maintained for 10 to 20 minutes in each range.

[0070] After the temperature drops to 300°C, the power supply to the upper heater 60 and the lower heater 70 will be cut off.

[0071] Afterwards, the silicon components will be naturally cooled from 300°C to below 100°C, and then cooled to below 100°C to complete the fusion process.

[0072] Since the process of flattening the welded surface through machining is a common procedure, its specific description is omitted.

Claims

1. A method for bonding silicon components using silicon powder and a high-frequency heating device, characterized in that, The steps include the following: A joint convex-concave structure is formed at the joint surface of the lower ring and the upper ring; The lower and upper rings are assembled into the silicon component bonding device; Single-crystal silicon powder is placed into the interlocking structure of the lower and upper rings; and The joint surface between the lower ring and the upper ring is heated and fused together. A positioning upper protrusion is formed on the bottom surface of the upper ring, and a positioning lower groove is formed on a portion of the upper surface of the lower ring to engage with the positioning upper protrusion of the upper ring. The positioning lower groove is formed between the outer center line and the outer circumference line between the center circumference line and the outer circumference line of the lower ring, or between the inner center line and the inner circumference line between the center circumference line and the inner circumference line of the lower ring.

2. The method of joining a silicon member using silicon powder and a high-frequency heating device according to claim 1, characterized by, In the step of forming a joint concave-convex structure on the mating surface of the lower ring and the upper ring, a protrusion is formed on the lower surface of the upper ring and a groove is formed on the upper surface of the lower ring to engage with the protrusion.

3. The method of joining a silicon member using silicon powder and a high-frequency heating device according to claim 2, characterized by, The aforementioned groove is a circular groove, which is symmetrical about the center circumference of the upper surface of the lower ring and forms the overall width of the upper surface of the lower ring.

4. The method of joining a silicon member using silicon powder and a high-frequency heating device according to claim 2, characterized by In the aforementioned groove, the deepest point formed from the upper surface of the lower ring is 3mm to 5mm, and the length of the same depth in the width direction of the upper surface of the lower ring at the deepest point reaches within 70% of the total width of the upper surface of the lower ring.

5. The method of joining silicon parts using silicon powder and a high frequency heating device according to claim 1, wherein The aforementioned positioning groove is a hemispherical groove.

6. The method of joining a silicon member using silicon powder and a high-frequency heating device according to Claim 1, wherein Between the upper ring and the lower ring, silicon powder, which serves as a welding agent, is first filled into the welding section. Then, the upper ring and the lower ring are respectively assembled into the upper fixing device and the lower fixing device of the molybdenum material of the silicon component bonding device.

7. The method of joining a silicon member using a silicon powder and a high-frequency heating device according to Claim 1, wherein The step of heating and welding the joint surface between the lower ring and the upper ring includes the following steps: A vacuum atmosphere is formed to 90 torr to 110 torr; The vacuum level is maintained at 50 Torr to 70 Torr by introducing argon gas; Pressure is applied between the assembled upper and lower rings by using an upper fixing device and a lower fixing device; The atmosphere temperature of the vacuum furnace containing the crucible is increased by operating the upper and lower heaters. The welded portion of the aforementioned joint surface is locally heated by operating a side heater capable of high-frequency induction heating; and Cool the welded section.

8. The bonding method for silicon components using silicon powder and a high-frequency heating device according to claim 7, characterized in that, By operating a side heater capable of high-frequency induction heating, the temperature of the molten weld area is kept within the range of 1500℃ to 1600℃.

9. The method of joining a silicon member using silicon powder and a high-frequency heating device according to claim 7, wherein In the step of cooling the welded part, after the welded part is melted, the power supply to the side heater that can realize high-frequency induction heating is cut off, so that the temperature of the upper heater and the lower heater drops to 1400°C, 1200°C, 1000°C, 900°C, 700°C, 500°C and 300°C respectively, and is maintained in each range for 10 to 20 minutes.

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