Temperature difference balance structure and plasma etching machine
By introducing a temperature difference balancing structure into the plasma etching machine and utilizing the combination of coils and heat-conducting plates, effective heat dissipation of the dielectric coupling window is achieved, thus solving the risk of cracking caused by temperature difference and improving the heat dissipation efficiency and etching rate of the etching machine.
Patent Information
- Application Number
- CN202422956858.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-02
- Publication Date
- 2025-11-07
- Estimated Expiration
- 2034-12-02
AI Technical Summary
The dielectric coupling window of existing plasma etching machines is at risk of cracking when the temperature difference is too large, and the existing heat dissipation method has poor cooling effect, which limits the radio frequency power and etching rate of the etching machine.
It adopts a temperature difference balance structure, including a coil and a heat-conducting plate. The coil is a hollow tube structure, coiled from the center to the edge, and the bottom is attached to the heat-conducting plate. The lower surface of the heat-conducting plate is flat to increase the contact area, and heat is dissipated through a combination of cooling medium circulation and air cooling.
It effectively balances the temperature difference of the dielectric coupling window, improves heat dissipation efficiency, enhances the cooling effect of the dielectric coupling window, and supports higher RF power and etching rate.
Smart Images
Figure CN223527124U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of semiconductor processing, especially to a temperature difference balance structure and plasma etching machine. BACKGROUND
[0002] The dielectric coupling window of the plasma etching machine is mostly made of ceramic material, when the overall temperature difference of the ceramic is too large, there is a risk of explosion, so the temperature difference between the center and the edge of the dielectric coupling window needs to be balanced by a corresponding cooling method. The current cooling effect is poor.
[0003] Therefore, how to improve the cooling effect of the dielectric coupling window has become a technical problem to be solved by the technical personnel in the field. SUMMARY
[0004] The utility model provides a temperature difference balance structure and plasma etching machine to improve the cooling effect of the dielectric coupling window.
[0005] In order to achieve the above purpose, the utility model provides the following technical scheme:
[0006] In the first aspect, the utility model provides a temperature difference balance structure, which comprises a dielectric coupling window and a coil, the coil is coiled from the center to the edge of the dielectric coupling window; the coil is a hollow tube structure, the coil comprises a first port and a second port, the first port and the second port are used for connecting cooling medium to circulate in the coil;
[0007] The bottom of the coil is provided with a heat conduction plate, the upper surface of the heat conduction plate is attached to the bottom of the coil, and the lower surface of the heat conduction plate is a plane.
[0008] In some embodiments, the bottom of the part opposite to the central region of the dielectric coupling window is provided with a heat conduction plate.
[0009] In some embodiments, the heat conduction plate comprises a clamping groove and a buckle, and the coil is placed in the clamping groove and clamped by the buckle.
[0010] In some embodiments, the coil is coiled along an involute.
[0011] In some embodiments, the heat conduction plate is made of metal.
[0012] In some embodiments, a heat conduction pad is laid between the coil and the dielectric coupling window.
[0013] In some embodiments, the heat conduction pad is made of silicone.
[0014] In some embodiments, the cooling medium is cooling water or refrigerant.
[0015] In some embodiments, a shielding cover is further arranged on the medium coupling window, and the side plate of the shielding cover is provided with heat dissipation holes, and the top plate of the shielding cover is provided with a fan.
[0016] In a second aspect, the application provides a plasma etching machine comprising the temperature difference balancing structure according to any one of the preceding aspects.
[0017] As can be seen from the above technical solution, the temperature difference balancing structure coil is a hollow pipe structure, cooling medium can be introduced into the coil through the first port and the second port of the coil to circulate in the coil, so as to balance the temperature difference between the center and the edge of the medium coupling window, effectively cool the medium coupling window, and thus improve the cooling effect of the medium coupling window. In addition, the heat conduction plate arranged at the bottom of the coil is attached to the bottom of the coil, and the lower surface of the heat conduction plate is a plane, so that the contact area between the coil and the medium coupling window is adjusted from the line-line contact of the prior art to the surface-surface contact, thereby increasing the contact area and further improving the cooling efficiency and the cooling effect of the medium coupling window. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some examples or embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative labor, and the present application can also be applied to other similar situations according to the provided drawings. Unless it is obvious from the language environment or otherwise stated, the same reference numerals in the drawings represent the same structure or operation.
[0019] Figure 1 A schematic diagram of a plasma etching machine provided by the embodiments of the present application;
[0020] Figure 2 A schematic diagram of a medium coupling window provided by the embodiments of the present application;
[0021] Figure 3 A perspective view of a temperature difference balancing structure provided by the embodiments of the present application;
[0022] Figure 4 A partial sectional view of a temperature difference balancing structure provided by the embodiments of the present application;
[0023] Figure 5 A top view of a temperature difference balancing structure provided by the embodiments of the present application;
[0024] Figure 6 A top perspective view of a coupling coil provided by the embodiments of the present application;
[0025] Figure 7 For Figure 6 enlarged view of part A in the middle;
[0026] Figure 8 is a bottom perspective view of a coupling coil provided by an embodiment of the utility model;
[0027] Figure 9 For Figure 8 enlarged view of part B in the middle;
[0028] In the illustration, 100-plasma etching machine; 200-wafer; 300-plasma;
[0029] 1-plasma reaction chamber; 2-dielectric coupling window; 3-shield cover; 4-coil; 5-excitation RF power supply; 6-excitation matching network; 7-bias electrode; 8-bias RF power supply; 9-bias matching network; 10-vacuum pump; 11-pressure control valve; 12-gas source; 13-nozzle; 14-fan; 15-heat conduction pad; 16-heat conduction plate; 41-first port; 42 second port; 161-buckle. DETAILED DESCRIPTION
[0030] The utility model will be further explained in detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related utility model, and not limited to the utility model. The described embodiments are only a part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the scope of the utility model protection.
[0031] Plasma etching machine (hereinafter referred to as etching machine), also called plasma plane etching machine, plasma etching machine, plasma surface treatment instrument, plasma cleaning system, etc., is applied to the semiconductor industry. Inductive coupling plasma (Inductively Coupled Plasma, ICP for short) etching method is the result of the joint action of chemical process and physical process. Its basic principle is that the RF output generated by the RF power supply is output to the annular coupling coil under vacuum low pressure, the mixed etching gas in a certain proportion is discharged by the coupling glow discharge, high-density plasma is generated, under the action of the radio frequency (RF) of the lower bias electrode, the semiconductor chemical bonds of the wafer pattern area are broken, and volatile substances are generated with the etching gas, which is in the form of gas, is removed from the vacuum pipeline.
[0032] Referring to Figure 1 , Figure 1 A structure diagram of an etching machine is shown.
[0033] The illustrated etching machine 100 includes a plasma reaction chamber (hereinafter referred to as a reaction chamber) 1, a shield cover 3, a dielectric coupling window 2, a coil 4, an excitation RF power supply 5, an excitation matching network 6, a bias electrode 7, a bias RF power supply 8, a bias matching network 9, a vacuum pump 10, a pressure control valve 11, a gas source 12, and a nozzle 13, wherein the reaction chamber 1, the dielectric coupling window 2, and the shield cover 3 are arranged in order from bottom to top; the coil 4 is arranged on the dielectric coupling window 2 and located in the shield cover 3; the process gas provided by the gas source 12 is sprayed into the reaction chamber 1 through the nozzle 13, and the excitation RF power supply 5 controls the coil 4 through the excitation matching network 6 to generate high-density plasma 300; the bias electrode 7 is located in the reaction chamber 1, the bias RF power supply 8 controls the bias electrode 7 through the bias matching network 9 and provides a bias voltage for the wafer 200 placed on the bias electrode 7; the vacuum pump 10 is in communication with the reaction chamber 1 through a vacuum pipe, the pressure control valve 11 is arranged on the vacuum pipe, and the pressure control valve 11 is used to switch the conduction state of the vacuum pipe; the gas source 12 is connected with the nozzle 13 arranged in the middle of the dielectric coupling window 2.
[0034] The etching process of the above-mentioned etching machine 100 is as follows: the process gas provided by the gas source 12 is sprayed into the reaction chamber 1 through the nozzle 13; the excitation RF power supply 5 controls the coil 4 to operate through the excitation matching network 6, the process gas entering the reaction chamber generates plasma 300 under the coupling action of the coil 4, and the plasma 300 accelerates to bombard the wafer 200 under the action of the bias electrode 7 to etch the wafer 200, and the volatile substances generated in the etching process are pumped away by the vacuum pump 10.
[0035] Etching is the most important process in the manufacturing process of semiconductor integrated circuits, among which the through silicon via (TSV) etching technology develops rapidly and has the advantages of low power consumption, small size, high performance, and high stacking density, which is widely recognized by the industry. In the etching process, the coil 4 above the cavity generates a certain magnetic field under the influence of radio frequency, which excites the gas to generate plasma, thereby realizing the etching of the wafer.
[0036] Referring to Figure 2The coil 4 is placed on the medium coupling window 2 above the reaction chamber, and needs to have the characteristics of high strength, insulation, high temperature resistance, resistance to various acid and alkali corrosion, and no reaction with other substances. On the one hand, the medium coupling window 2 is placed on the reaction chamber 1 and is used for sealing the vacuum degree of the reaction chamber 1. On the other hand, the medium coupling window 2 has a relatively large resistance and is used to prevent the coil 4 from being conducted with the reaction chamber 1. The commonly used medium coupling window 2 materials are ceramic, quartz and the like. Since the plasma generated by the excited electric field has very high energy, the higher the radio frequency power, the greater the density of the excited plasma, and the closer to the center of the medium coupling window 2, the stronger the electric field, the greater the density of the excited plasma, and the greater the heat released by ion impact, resulting in a higher temperature closer to the center of the medium coupling window 2, and a lower temperature at the edge of the medium coupling window 2 compared with the center. Since the medium coupling window 2 is mostly made of ceramic material, when the overall temperature difference of the ceramic is too large, there is a risk of explosion, so a corresponding cooling method is needed to balance the temperature difference between the center and the edge of the medium coupling window 2. At present, the common heat dissipation method is to realize the cooling of the medium coupling window 2 through the cooling effect of the fan, and the fan is fixed above the medium coupling window 2 and dissipates heat through the heat transfer medium of the atmosphere. The heat dissipation method of the fan can cope with some processes with small power, but the cooling effect of the fan is poor, and the heat dissipation effect is insufficient to cope with the temperature generated by high radio frequency power. At present, although deep silicon etching can be realized in the etching process, the cooling effect is poor, the radio frequency power used in the etching process is low, the excited plasma density is small, and the etching rate is low, which is insufficient to cope with the development of the semiconductor industry.
[0037] To solve the above technical problems, the temperature difference balancing structure disclosed in the embodiments of the present application improves the cooling effect of the medium coupling window, improves the heat dissipation effect of the medium coupling window, and further improves the radio frequency power of the etching machine.
[0038] Referring to Figures 3 to 9 The temperature difference balancing structure disclosed in the present application includes a medium coupling window and a coil 4, and the coil 4 is coiled from the center to the edge of the medium coupling window. The coil 4 is a hollow tube structure, and the coil 4 includes a first port 41 and a second port 42 for connecting a cooling medium to circulate in the coil 4. The bottom of the coil 4 is provided with a heat conduction plate 16, the upper surface of the heat conduction plate 16 is in close contact with the bottom of the coil 4, and the lower surface of the heat conduction plate 16 is a plane.
[0039] The temperature difference balance structure coil 4 is a hollow tube structure, cooling medium can be introduced into the coil 4 through the first port 41 and the second port 42 of the coil 4 to circulate in the coil 4, the temperature difference between the center and the edge of the medium coupling window can be balanced, the medium coupling window can be effectively cooled, and the cooling effect of the medium coupling window is improved. In addition, the heat conduction plate 16 arranged at the bottom of the coil 4 is attached to the bottom of the coil 4, and the lower surface of the heat conduction plate 16 is a plane, so that the contact area of the coil 4 and the medium coupling window is adjusted from the line-line contact of the prior art to the surface-surface contact, thereby increasing the contact area and further improving the heat dissipation efficiency and the cooling effect of the medium coupling window.
[0040] In order to improve the heat conduction between the balance coil 4 and the medium coupling window, a heat conduction pad 15 is arranged between the coil 4 and the medium coupling window. The heat conduction pad 15 is a soft material with heat conduction and insulation properties, for example, the heat conduction pad 15 is a silica gel material.
[0041] It should be noted that the bottom of the coil 4 is provided with the heat conduction plate 16, or the bottom of the coil 4 is provided with the heat conduction plate 16, and the cost of arranging the heat conduction plate 16 and the characteristics of heat distribution of the medium coupling window are considered. In some examples of the present application, the bottom of the part opposite to the center area of the coil 4 and the medium coupling window is provided with the heat conduction plate 16, and the contact area of the coil 4 and the medium coupling window can be increased by the heat conduction plate 16, so as to improve the heat dissipation effect.
[0042] The above-mentioned heat conduction plate 16 can be bonded to the outer periphery of the coil 4, or in some examples of the present application, the heat conduction plate 16 includes a clamping groove and a clamping buckle 161, and the coil 4 is placed in the clamping groove and clamped by the clamping buckle 161. The clamping buckle 161 is arranged at the clamping groove. The clamping buckles 161 are symmetrically arranged on both sides of the clamping groove, or staggered arrangement. The heat conduction plate 16 is made of metal material, and has high heat conduction efficiency.
[0043] The above-mentioned coil 4 is gradually opened and wound, or spirally wound, etc. The coil 4 is a hollow tube structure, specifically, the cross section of the coil 4 is a hollow circular ring or an ellipse.
[0044] The cooling medium introduced into the coil 4 is cooling water or refrigerant, and the circulation of the cooling medium can cool the coil 4, and the reduction of the heat of the coil 4 can also reduce the temperature transfer to the medium coupling window.
[0045] In addition, the cover on the medium coupling window is provided with a shielding cover, the side plate of the shielding cover is provided with a heat dissipation hole, and the top plate of the shielding cover is provided with a fan 14. The fan 14 and the heat dissipation hole cooperate to form air cooling heat dissipation, and the air cooling heat dissipation and the cooling medium heat dissipation are combined together, which can further improve the heat dissipation effect, and thus the coil 4 can adopt a high-power structure.
[0046] In combination Figure 1 , seeFigures 2 to 9 The application provides a plasma etching machine 100 comprising the temperature difference balancing structure according to any one of the above. Since the temperature difference balancing structure has the above beneficial effects, the plasma etching machine 100 comprising the temperature difference balancing structure has corresponding effects, which will not be described here.
[0047] The medium coupling window 2 and the central air inlet assembly 130 are made of non-metallic materials, such as ceramics, quartz, etc.
[0048] The terms "first", "second", etc. are used only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second", etc. can explicitly or implicitly include one or more of the features.
[0049] The above description is only the preferred embodiment of the present application and the explanation of the applied technical principles, and is not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. The scope of the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above inventive concept. For example, the technical solutions formed by the mutual replacement of the above features and the technical features disclosed in the present application (but not limited to) having similar functions.
Claims
1. A temperature difference balancing structure, characterized by, The medium coupling window and the coil are included, the coil is coiled from the center to the edge of the medium coupling window, the coil is a hollow tube structure, the coil includes a first port and a second port, the first port and the second port are used for connecting a cooling medium to circulate in the coil; The bottom of the coil is provided with a heat conduction plate, the upper surface of the heat conduction plate is attached to the bottom of the coil, and the lower surface of the heat conduction plate is a plane.
2. The temperature difference balancing structure according to claim 1, wherein The bottom of the coil opposite to the center area of the medium coupling window is provided with the heat conduction plate.
3. The temperature difference balancing structure according to claim 2, wherein The heat conduction plate includes a clamping groove and a buckle, the coil is placed in the clamping groove and clamped by the buckle.
4. The temperature difference balancing structure according to claim 2, wherein The coil is coiled along an involute.
5. The temperature equalization structure according to any one of claims 1 to 4, wherein The heat conduction plate is made of metal.
6. The temperature difference balancing structure according to claim 1, wherein A heat conduction pad is laid between the coil and the medium coupling window.
7. The temperature difference balancing structure according to claim 6, wherein The heat conduction pad is made of silica gel.
8. The temperature equalization structure of any one of claims 1 to 6, wherein, The cooling medium is cooling water or refrigerant.
9. The temperature equalization structure of any one of claims 1 to 6, wherein, A shielding cover is further included, the shielding cover is arranged on the medium coupling window, the side plate of the shielding cover is provided with heat dissipation holes, and the top plate of the shielding cover is provided with a fan.
10. A plasma etching machine, characterized by, The temperature difference balancing structure includes the temperature difference balancing structure according to any one of claims 1 to 9.