A copper-glass plasma electrode structure

Abstract

The present invention relates to a copper-glass plasma electrode structure, which is provided with an electrode plate, a plasma chamber, a sealing ring, a water-cooling coil, glass, and an adapter. The electrode plate is made of oxygen-free copper, and three concentric grooves of different diameters are milled on the upper end surface. Glass is concentrically assembled in the first groove with the smallest diameter to prevent the plasma from sputtering the electrode plate; the second groove with a slightly larger diameter is used to cooperate with the plasma chamber; and a water-cooling coil is welded in the open groove with the largest diameter to provide heat removal for the electrode plate. Adapters are welded at both ends of the water-cooling coil to facilitate the connection of cooling pipes. Through the structure described in the present invention, the characteristics of high thermal conductivity of copper and low composite coefficient of glass are effectively combined, so that the plasma electrode structure can not only provide excellent cooling capacity but also effectively reduce the sputtering caused by the electrode being bombarded by plasma, thereby increasing the proportion of target ions in the extracted ion beam.

Description

Technical Field

[0001] The present invention relates to the field of plasma discharge devices, and in particular to a copper-glass plasma electrode structure. Background Art

[0002] Inductively coupled plasma (ICP) is widely used across various industries, particularly in the semiconductor field, where it is often used for wafer etching and chamber cleaning. The development of semiconductor manufacturing technology is inseparable from inductively coupled plasma.

[0003] At the same time, the plasma-stimulating chamber and plasma electrodes are inevitably bombarded by the plasma, resulting in sputtering. The current solution is typically to use quartz and Al2O3 materials to make the chamber and electrodes. While these two materials have low surface recombination coefficients and are less prone to sputtering, their low thermal conductivity prevents sufficient heat removal from the vacuum seals near the electrodes, limiting stable operation time. How to ensure that the plasma electrode structure can simultaneously meet cooling requirements and minimize sputtering is an important issue that needs to be addressed. Summary of the Invention

[0004] To address the problem of ensuring cooling capacity while effectively preventing severe sputtering in the aforementioned plasma electrode, the present invention provides a copper-glass plasma electrode structure. This structure combines the high thermal conductivity of copper and the low composite coefficient of glass, providing excellent cooling capacity while effectively reducing sputtering caused by plasma bombardment of the electrode.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] A copper-glass plasma electrode structure, comprising: an electrode plate, a plasma chamber, a first sealing ring, a second sealing ring, a water-cooling coil, glass, and an adapter;

[0007] The electrode plate is made of oxygen-free copper, and has three concentric grooves on its upper end surface, which are groove 1, groove 2 and an open groove with successively increasing diameters.

[0008] Among them, the glass is concentrically assembled in the first trough; the second trough is used to cooperate with the plasma chamber, and the second sealing ring is placed inside the second trough, and the plasma chamber is located on the second sealing ring; the water-cooling coil is welded in the open trough to provide heat removal for the electrode plate.

[0009] Furthermore, a through hole is opened in the center of the sink for drawing out plasma, and the bottom surface of the glass is in contact with an upper surface of the sink.

[0010] Furthermore, the glass is cylindrical, with a quartz rim at the top. Due to its low height, the glass structure resembles a petri dish with a rim. Quartz, compared to copper, has a lower surface recombination coefficient, thus fully protecting the surface of the sink exposed to the plasma chamber and effectively preventing plasma from sputtering the electrode plate.

[0011] Furthermore, the plasma chamber is a cylindrical structure made of quartz glass or Al2O3; a step portion extending outward through an arc transition is provided at the contact point between its bottom end surface and the second sealing ring to increase the sealing area with the second sealing ring, evenly disperse the downward pressure generated after the plasma chamber is tightened, and avoid stress concentration in the glass tube.

[0012] Furthermore, the water-cooling coil is made of red copper, oxygen-free copper or SUS304 material, and has a rectangular tube cross-section. Its three sides are in contact with the open grooves on the electrode plate. Compared with traditional round tubes, the contact area with the electrode plate is increased, thereby improving the cooling capacity.

[0013] Furthermore, the water-cooling coil is externally connected to two adapters, one end of the adapter is welded to the water-cooling coil, and the other end is connected to the water pipe; the adapter is made of SUS304 or SUS316 or copper material, and the end face of the adapter that cooperates with the water-cooling coil is provided with a rectangular groove, and the other end is a standard compression sleeve pipe joint, which is convenient for disassembly and assembly with the water pipe and replacement of parts.

[0014] Furthermore, the coolant introduced into the cooling coil is a liquid with insulation and certain thermal conductivity.

[0015] Furthermore, the cooling liquid is fluorinated liquid or deionized water.

[0016] Furthermore, the electrode structure also includes a chamber structure located below the electrode plate, and the electrode plate is threadedly connected to the chamber structure by fastening screws; the interior of the chamber structure serves as a working space for the induced plasma and is provided with a sputtering base or target material.

[0017] Furthermore, the sealing ring 1 is placed in the sealing groove on the upper surface of the chamber structure. After the electrode plate and the chamber structure are screwed together, the sealing ring 1 is squeezed to form a vacuum seal between the electrode plate and the chamber structure.

[0018] In summary, the beneficial effects of the present invention are:

[0019] 1. By utilizing the high thermal conductivity of copper and the low composite coefficient of glass, the electrode structure has good heat removal capabilities and reduces plasma sputtering, thereby increasing the proportion of target ions in the extracted ion beam;

[0020] 2. The electrode structure is made of copper and glass. The materials are easy to obtain, the processing technology is simple, the cost is low, the efficiency is high, and the applicability is high; BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below with reference to the accompanying drawings and examples.

[0022] Figure 1 It is an overall schematic diagram of the plasma electrode structure of the present invention.

[0023] Figure 2 It is a schematic diagram of the installation of the plasma electrode structure of the present invention.

[0024] Figure: 1, chamber structure; 2, electrode plate; 3, fastening screw; 4, plasma chamber; 5, sealing ring 1; 201, water cooling coil; 202, glass; 203, sealing ring 2; 204, adapter; 205, sink 1; 206, sink 2; 207, open sink; DETAILED DESCRIPTION

[0025] The present invention is described in detail below with reference to the embodiments shown in the accompanying drawings:

[0026] like Figure 1 、 2 As shown, the copper-glass plasma electrode structure described in the present invention comprises: an electrode plate 2, a plasma chamber 4, a second sealing ring 203, a water-cooling coil 201, a glass 202, an adapter 204, a first sink 205, a second sink 206, and an open sink 207. Three concentric sinks of varying diameters are milled onto the upper end face of the electrode plate 2. The smallest-diameter sink 205 has a central hole for plasma extraction and is concentrically assembled with the glass 202, with the bottom surface of the glass 202 aligned with the surface of the first sink 205. The slightly larger-diameter sink 206 mates with the plasma chamber 4, with the second sealing ring 203 intervening between them. When the plasma chamber 4 is tightened, pressure exerted on the second sealing ring 203 compresses the second sealing ring, thereby forming a vacuum seal with the electrode plate 2. The largest-diameter open sink 207 houses the water-cooling coil 201. The two are concentrically assembled and welded together. Coolant circulates within the water-cooling coil 201, removing heat from the electrode plate 2. The water-cooling coil 201 is externally connected to two adapters 204 . One end of the adapter 204 is welded to the water-cooling coil 201 , and the other end is connected to a water pipe.

[0027] Electrode plate 2 is drilled with screw holes distributed around its circumference and is threadedly connected to chamber structure 1 at its lower end via set screws 3. Sealing ring 1 (5) is placed in a sealing groove on the upper surface of chamber structure 1. After the electrode plate 2 and chamber structure 1 are screwed together, sealing ring 1 (5) is squeezed to form a vacuum seal between the electrode plate 2 and chamber structure 1.

[0028] The electrode plate 2 is made of oxygen-free copper, has a diameter of 120-200 mm, and is provided with 6 M6-M8 matching through holes. A 4-8 mm through hole is drilled in the center of the sink 1 205 .

[0029] The glass 202 is made of quartz glass and has an overall shape similar to a petri dish with a rim. The glass bottom has a diameter of 30-36 mm and a rim width of 2-4 mm. A 5-9 mm through-hole is provided in the center of the glass bottom. The bottom thickness is 1-1.5 mm, and the annular sidewall thickness is 2-3 mm.

[0030] The plasma chamber 4 is a cylindrical structure made of quartz glass or Al2O3. Its inner diameter is 34-40 mm, and its wall thickness is 2-4 mm. The bottom surface, where it contacts the electrode plate and the sealing ring, is fired with a large step and uses a circular arc transition to increase the sealing area with the sealing ring. Furthermore, when the plasma chamber is tightened, the extrusion force is evenly distributed across the electrode plate surface, avoiding stress concentration in the glass tube.

[0031] The water-cooling coil 201 is made of copper / oxygen-free copper / SUS304, with a cross-section of 8x6mm rectangular tube and a wall thickness of 1-2mm. The rectangular structure increases the contact area with the electrode plate compared to a circular structure, thereby improving cooling capacity.

[0032] The cooling liquid is a liquid with insulation and certain heat conductivity, such as fluorinated liquid / deionized water.

[0033] The adapter 204 is made of SUS304 / SUS316 / copper. An 8x6mm groove, 6-9mm deep, is milled on one end to facilitate welding with the water-cooling coil. The other end is a compression fitting, conforming to GB / T 3733-2008.

[0034] The chamber structure 1 is made of SUS316 material and has a cylindrical shape. A sputtering base or target can be placed inside according to actual use requirements.

[0035] Preferably, the sealing ring 1 5 is made of fluororubber, placed in the sealing groove of the chamber structure 1, with its end face in contact with the electrode plate 2, and a seal is formed by tightening and squeezing the electrode plate and the chamber thread.

[0036] Preferably, the second sealing ring 203 is made of fluororubber and is placed in the open sink groove 207 of the electrode plate 2, with its end face in contact with the plasma chamber, and is sealed by being pressed downward by the plasma chamber.

Claims

1. A copper-glass plasma electrode structure, characterized in that: The electrode structure includes: an electrode plate, a plasma chamber, a sealing ring 1, a sealing ring 2, a water-cooling coil, glass and an adapter; The electrode plate is made of oxygen-free copper, and has three concentric grooves on its upper end surface, which are groove 1, groove 2 and an open groove with successively increasing diameters. Among them, the glass is concentrically assembled in the first trough; the second trough is used to cooperate with the plasma chamber, and the second sealing ring is placed inside the second trough, and the plasma chamber is located on the second sealing ring; the water-cooling coil is welded in the open trough to provide heat removal for the electrode plate.

2. The copper-glass plasma electrode structure according to claim 1, characterized in that: A through hole is opened in the center of the sink for drawing out plasma, and the bottom surface of the glass is in contact with an upper surface of the sink.

3. The copper-glass plasma electrode structure according to claim 2, characterized in that: The glass is cylindrical, with an edge ring on the upper end surface, and is made of quartz.

4. The copper-glass plasma electrode structure according to claim 1, characterized in that: The plasma chamber is a cylindrical structure made of quartz glass or Al2O3; a step portion extending outward through an arc transition is provided at the contact point between the bottom end surface and the second sealing ring.

5. The copper-glass plasma electrode structure according to claim 1, characterized in that: The water-cooling coil is made of red copper, oxygen-free copper or SUS304 material, and has a rectangular tube cross section. Three sides of the water-cooling coil are in contact with the open sinks on the electrode plate.

6. The copper-glass plasma electrode structure according to claim 5, characterized in that: The water-cooling coil is connected to two adapters, one end of which is welded to the water-cooling coil and the other end is connected to the water pipe; the adapter is made of SUS304 or SUS316 or copper material, and the end face of the adapter that cooperates with the water-cooling coil is provided with a rectangular groove, and the other end is a standard compression sleeve pipe joint.

7. The copper-glass plasma electrode structure according to claim 5, characterized in that: The coolant introduced into the water-cooling coil is a liquid with insulation and certain heat conductivity.

8. The copper-glass plasma electrode structure according to claim 7, characterized in that: The cooling liquid is fluorinated liquid or deionized water.

9. The copper-glass plasma electrode structure according to claim 2, characterized in that: The electrode structure also includes a chamber structure located below the electrode plate, and the electrode plate is threadedly connected to the chamber structure through a fastening screw; the interior of the chamber structure serves as a working space for the induced plasma and is provided with a sputtering base or target material.

10. The copper-glass plasma electrode structure according to claim 9, characterized in that: The sealing ring 1 is placed in the sealing groove on the upper surface of the chamber structure. After the electrode plate and the chamber structure are screwed together, the sealing ring 1 is squeezed to form a vacuum seal between the electrode plate and the chamber structure.

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