Ceramic base

Abstract

The present invention relates to a ceramic base, which may include: a substrate having a cooling gas flow path for supplying cooling gas; an insulating plate fixed on the substrate having a through-hole in the thickness direction; and a discharge prevention pin inserted into the through-hole and extending along the length direction of the through-hole.

Description

Technical Field

[0001] This invention relates to a ceramic base, and more particularly to a pin for preventing abnormal discharge of pores. Background Technology

[0002] Typically, semiconductor devices or display devices are manufactured by sequentially stacking multiple thin film layers, including dielectric and metal layers, onto a glass substrate, flexible substrate, or semiconductor wafer substrate, and then using patterned semiconductor processes. In particular, in reactive ion etching (RIE) equipment, a ceramic substrate may be provided to support the glass substrate, flexible substrate, or semiconductor wafer substrate and for patterned dry etching processes. This ceramic substrate may also be provided with high-frequency (RF) electrodes, allowing for plasma generation during etching processes of the thin film layers formed on the substrate. Furthermore, the ceramic substrate may also be provided with suction cup electrodes for supporting the substrate or heating wires for heating the substrate.

[0003] Figures 1a to 1c This diagram is used to illustrate the problems with existing ceramic bases. Figure 1a and Figure 1b This diagram illustrates an example of an electric arc occurring in the pore portion during a dry etching process on an existing ceramic substrate. Figure 1c This is a diagram showing the wear condition of the discharge prevention pin inserted into the pore of an existing ceramic base.

[0004] Reference Figures 1a to 1c Typically, the lifespan of a ceramic base is 5000 to 15000 hours, and depending on the usage environment, it can be used for approximately 10 to 30 months. During this time, the discharge prevention pins in the porous portion of the ceramic base are exposed to plasma for extended periods and generate [effects such as...]. Figure 1c The wear shown. Therefore, when the plasma resistance of the discharge prevention pin, which is typically inserted into an air hole with a diameter of less than 1 mm, is poor, such as... Figure 1a and Figure 1b As shown, there is a problem of severe wear leading to induced arcing. This determines the lifespan of the ceramic substrate, thus requiring improvement. Summary of the Invention

[0005] The problem the invention aims to solve

[0006] Therefore, the present invention is proposed to solve the above-mentioned problems. The purpose of the present invention is to provide a ceramic base that can reduce the occurrence of electric arc and improve the life of the ceramic base by improving the discharge prevention pin of the pores and the plasma resistance characteristics.

[0007] means for solving problems

[0008] First, to summarize the features of the present invention, a ceramic base for achieving the stated object may include: a substrate having a cooling gas flow path for supplying cooling gas; an insulating plate fixed to the substrate having a through-hole in the thickness direction; and a discharge prevention pin inserted into the through-hole and extending along the length direction of the through-hole.

[0009] The discharge prevention pin is preferably made of a material with a volume resistivity in the range of 1E14Ωcm to 1E15Ωcm.

[0010] The end cross-sectional area of ​​the discharge prevention pin can be 50% to 90% of the cross-sectional area of ​​the vent.

[0011] The discharge prevention pin may include an Al2O3-SiC composite material.

[0012] The Al2O3-SiC composite material preferably contains 3wt% to 10wt% SiC.

[0013] The volume resistivity of the Al2O3-SiC composite material at room temperature is preferably above 1E15Ωcm, and at 200℃ it is above 1E14Ωcm.

[0014] The discharge prevention pin can be inserted into the air hole with a diameter of less than 1 mm.

[0015] The ceramic base may include an electrode layer located within the insulating plate, and the electrode layer may include one or more of an electrostatic chuck electrode, a high-frequency electrode, or a heating wire.

[0016] Invention Effects

[0017] According to the present invention, the ceramic base, as a material for a discharge prevention pin with pores, can use a material containing 3 wt% to 10 wt% SiC mixed in Al2O3, maintaining the plasma etching rate in the range of 0.02 μm / min to 0.1 μm / min, and ensuring that the volume resistivity of the material is above 1E15 Ωcm at room temperature and above 1E14 Ωcm at 200°C, thereby improving plasma resistance and increasing the lifespan of the ceramic base. That is, the discharge prevention pin of the present invention does not wear due to improved plasma resistance, thus preventing the formation of electron acceleration spaces in the pores and preventing abnormal discharge. Furthermore, by maintaining the volume resistivity of the above material, the occurrence of high potential differences that could induce abnormal discharge at high resistance can be prevented, and the increase of current that could induce abnormal discharge at low resistance can be prevented. Attached Figure Description

[0018] To aid in understanding the invention, embodiments of the invention are provided in the accompanying drawings, which are included as part of the detailed description and serve to illustrate the technical concept of the invention.

[0019] Figures 1a to 1c This diagram is used to illustrate the problems with existing ceramic bases.

[0020] Figure 2 This is a schematic cross-sectional view of a ceramic base according to an embodiment of the present invention.

[0021] Figure 3 yes Figure 2 An enlarged sectional view of section AA.

[0022] Figure 4 It is used for explanation Figure 2 The diagram illustrates abnormal discharge caused by wear of the pin in the vent section.

[0023] Figure 5 This is an actual experimental photograph showing a clean state with no abnormal discharge around the pores on the upper surface of the ceramic base according to an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 15: Cooling gas flow path

[0026] 30: Stomata

[0027] 55: Discharge prevention pin

[0028] 200: Substrate

[0029] 300: Insulation board

[0030] 320: Electrode layer Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings. In these drawings, the same constituent elements will be indicated by the same reference numerals wherever possible. Furthermore, detailed descriptions of known functions and / or structures will be omitted. The following disclosure focuses on explaining the parts necessary to understand the operation of various embodiments, and omits descriptions of elements that may obscure the main points of the description. Additionally, some constituent elements in the drawings may be enlarged or omitted, or shown in a schematic manner. The sizes of the constituent elements do not perfectly reflect their actual sizes; therefore, the content described herein is not limited to the relative sizes or spacing of the constituent elements shown in the various drawings.

[0032] In describing embodiments of the present invention, detailed descriptions of relevant prior art will be omitted when it is determined that such detailed descriptions would unnecessarily obscure the spirit of the invention. Furthermore, the terminology used below, defined in consideration of the functionality within the invention, may be changed according to the intent or convention of the user or practitioner. Therefore, definitions should be based on the entire contents of this specification. The terminology used in the detailed description is for describing embodiments of the invention only and should not be limiting. Unless otherwise expressly stated, a single quantity includes the meaning of multiple quantities. In this description, expressions such as "comprising" or "provided with" are used to indicate certain characteristics, numbers, steps, actions, elements, and parts or combinations thereof, and should not be construed as excluding the presence or possibility of one or more other characteristics, numbers, steps, actions, elements, and parts or combinations thereof other than those described.

[0033] In addition, terms such as "first" and "second" can be used to describe multiple constituent elements, but the constituent elements are not limited to these terms. These terms are only used to distinguish one constituent element from other constituent elements.

[0034] Firstly, in this invention, the ceramic substrate is a semiconductor device used to process substrates for various applications (such as semiconductor wafers, glass substrates, flexible substrates, etc.). To support the substrate, an electrostatic chuck electrode, acting as an electrostatic chuck, can be provided. To heat the substrate at a specified temperature, a heating wire (or heating element) for a heater can be provided. Alternatively, to perform process treatments on the substrate (such as plasma-enhanced chemical vapor deposition), a high-frequency electrode can be provided, or a high-frequency electrode can replace the heating wire. For example, the ceramic substrate of this invention is applicable not only to reactive ion etching (RIE) equipment but also to equipment used in chemical vapor deposition (CVD) and physical vapor deposition (PVD) processes.

[0035] Therefore, as described below, the ceramic base of the present invention is a structure that bonds a substrate including a cooling gas flow path to an insulating plate including an electrode layer. It should be noted beforehand that the electrode layer disposed on the insulating plate should be understood to include a conductor, which is used to perform any one or more of the functions of an electrostatic chuck electrode, a high-frequency electrode, or a heating wire (or heating element) as described above.

[0036] Figure 2 This is a schematic cross-sectional view of a ceramic base 100 according to an embodiment of the present invention.

[0037] Reference Figure 2In one embodiment of the present invention, a ceramic base 100 includes a substrate 200 and an insulating plate 300 bonded together by an adhesive 312. The ceramic base 100 is preferably circular, but may also be designed as other shapes such as elliptical or quadrilateral, depending on the circumstances.

[0038] The substrate 200 can be formed as a multi-layer structure composed of multiple metal layers. These metal layers can be bonded together using processes such as brazing, welding, or bonding. The insulating plate 300 is fixed to the substrate 200 and can be fixed to the substrate 200 using specified fixing units or adhesive / bonding units. The substrate 200 and the insulating plate 300 can be prepared separately and then bonded together. Depending on the situation, the insulating plate 300 structure can also be directly formed on the upper surface of the substrate 200 using a ceramic sheet or the like.

[0039] like Figure 2 The insulating plate 300 includes an electrode layer 320 disposed between ceramic sheets or a ceramic material made of powder. As one embodiment, the ceramic material may be made of a substance selected from alumina (Al2O3), aluminum nitride (AlN), silicon carbide (SiC), silicon nitride (Si3N4), silicon oxide (SiO2), barium oxide (BaO), zinc oxide (ZnO), cobalt oxide (CoO), tin oxide (SnO2), zirconium oxide (ZrO2), Y2O3, YAG, YAM, YAP, etc. The insulating plate 300 can be formed by thermal spraying and ceramic sheet attachment processes using the aforementioned ceramic material on the upper surface of the substrate 200.

[0040] The electrode layer 320 may be made of a conductive metallic material. For example, the electrode layer 320 may be formed from at least one of silver (Ag), gold (Au), nickel (Ni), tungsten (W), molybdenum (Mo), and titanium (Ti), more preferably from tungsten (W). The electrode layer 320 may be formed using a thermal spraying process or a screen printing process. The electrode layer 320 has a thickness of approximately 1.0 μm to 100 μm. For example, preferably, when the electrode layer 320 is formed by a screen printing process, a thickness of 1.0 μm to 30 μm is suitable, and when the electrode layer 320 is formed by a thermal spraying process, a thickness of 30 μm to 100 μm is suitable. However, it is difficult to form a layer that is too thin (e.g., the thickness of the electrode layer 320 is less than 1.0 μm), and therefore this is not preferred. Furthermore, in this case, the porosity and other defects in the electrode layer will lead to an increase in resistance, and the increase in resistance may result in a decrease in electrostatic adsorption force, which is also not preferred. Furthermore, when the thickness of the electrode layer 320 is too thick (e.g., exceeding 100 μm), arcing may occur, which is not preferable. Therefore, the thickness of the electrode layer 320 is preferably used within the range of approximately 1.0 μm to 100 μm. As an example, the electrode layer 320 formed in the above manner can be an electrostatic chuck electrode as described below, which receives a bias voltage and generates electrostatic force when a substrate (not shown) placed on top of the dielectric layer 330 is loaded, thereby performing chucking, and releases the chucking by applying a reverse bias voltage to the electrode layer 320 to induce discharge when the substrate (not shown) is unloaded.

[0041] However, this is not the only limitation. Depending on the circumstances, the electrode layer 320 may also include an electrode pattern for a heater or a high-frequency electrode pattern for generating plasma. That is, the ceramic substrate 100 of the present invention is a semiconductor device for processing substrates (semiconductor wafers, glass substrates, flexible substrates, etc.) for various applications. In order to support the substrate, an electrostatic chuck electrode may be provided on the electrode layer 320, which serves as an electrostatic chuck. In order to heat the substrate at a specified temperature, a heating wire (or heating element) may be provided. Alternatively, in order to perform process processing (such as plasma-enhanced chemical vapor deposition) on the substrate, a high-frequency electrode may be provided, or a high-frequency electrode may be used instead of a heating wire.

[0042] When the ceramic base 100 is installed inside a cavity used in semiconductor processes, in order to use external cooling gas to uniformly cool the substrate (e.g., glass substrate, flexible substrate, and semiconductor wafer substrate) on the insulating plate 300, a plurality of cooling vents 30 formed on the insulating plate 300 may be provided, and the plurality of cooling vents 30 are in fluid communication with the cooling gas flow path 15 of the substrate 200.

[0043] In addition, in the ceramic base 100 of the present invention, each pore 30 is inserted with a discharge prevention pin 55. For example, in semiconductor processes (etching processes, etc.), when an RF high-frequency voltage or a low-frequency voltage is applied simultaneously or separately to the electrode layer 320 through the electrode rod 281 of the substrate 200, abnormal discharge (micro arcing or parasitic plasma, etc.) can be suppressed so that the etching process can proceed stably.

[0044] Figure 3 yes Figure 2 An enlarged sectional view of section AA.

[0045] Reference Figure 3 For example, the interior of the substrate 200 has a suitable pattern (such as...) Figure 2 The cooling gas flow path 15 (shown) is used to supply cooling gas. The cooling gas flow path 15 can be pre-formed in the metal material of the substrate 200. For example, as shown, the upper end of the cooling gas flow path 15 can also be a through hole formed in a porous structure 50 contained within the substrate 200. In the manufacturing process of the ceramic base 100 of the present invention, an adhesive 312 can be used to bond the insulating plate 300 to the substrate 200.

[0046] The substrate 200 and the insulating board 300 can be firmly bonded together by pressing, sintering, and curing. Next, holes for penetrating the adhesive layer of the insulating board 300 and the adhesive 312 can be machined at the locations of the pores 30 using a machining center (MCT), or, if necessary, holes can be machined to further penetrate the pore structure 50 of the substrate 200, thereby creating fluid communication between the cooling gas flow path 15 and the pores 30. The holes described above can be machined using laser processing or similar methods with an MCT, thus enabling the machining of holes with diameters of several millimeters or less, or preferably, holes with diameters of 1 mm or less.

[0047] Cooling vents 30, which penetrate the insulating plate 300 as described above, in the thickness direction, can eject cooling gas from the cooling gas flow path 15 to uniformly cool the substrate on the insulating plate 300. "Penetrating in the thickness direction" means that the vents 30 are configured to provide a passage of any shape connecting the upper and lower surfaces of the insulating plate 300. Specifically, the passage shape can be such that it penetrates the entire insulating plate 300 with its surface facing directly downwards, or it can be achieved through a combination of vertical and horizontal channels. Helium (He) is primarily used as the cooling gas, but it is not limited to this. The cooling vents 30 of the insulating plate 300 can be composed of an appropriate number according to the design.

[0048] exist Figure 2In this process, a bias voltage can be applied to the electrode layer 320 from one or more electrode rods 281 arranged through a lower hole 280 of the ceramic substrate 100. This bias voltage is used for clamping and releasing, or for providing heating or high frequency. According to the design, cooling vents 30 can be formed in an appropriate number between the predetermined electrode patterns forming the electrode layer 320, and fluid communication of cooling gas from the cooling gas flow path 15 to the upper surface of the insulating plate 300 can be achieved through the cooling vents 30.

[0049] Furthermore, in the ceramic base 100 of the present invention, each cooling vent 30 is inserted with a discharge prevention pin 55. For example, in semiconductor processes (etching processes, etc.), when an RF high-frequency voltage or a low-frequency voltage is applied simultaneously or separately to the electrode layer 320 through the electrode rod 281 of the substrate 200, abnormal discharges (micro arcing or parasitic plasma, etc.) can be suppressed so that the etching process can proceed stably.

[0050] A discharge prevention pin 55 is inserted into an air hole 30 with a diameter of a few millimeters or less, or preferably 1 mm or less, and the diameter of the discharge prevention pin 55 is appropriately smaller than the diameter of the air hole 30. For example, the end cross-sectional area of ​​the discharge prevention pin 55 is preferably 50% to 90% of the cross-sectional area of ​​the air hole 30, thereby preferably allowing cooling gas to pass through the gap between the air hole 30 and the discharge prevention pin 55 to fully form fluid communication.

[0051] The discharge prevention pin 55 can be inserted into the vent 30 and extends downward along the length of the vent 30, allowing it to be fixed in various ways and preventing the discharge prevention pin 55 from protruding above the vent 30. For example, preferably, the end height of the vent 30 is the same as the end height of the discharge prevention pin 55. However, the end height of the discharge prevention pin 55 should be above the end height of the vent 30.

[0052] Figure 4 It is used for explanation Figure 2 The diagram shows the abnormal discharge caused by the wear of the anti-discharge pin 55 in the vent 30 section.

[0053] Reference Figure 4 The discharge prevention pin 55 ensures the stable operation of plasma-based processes. However, when the discharge prevention pin 55 is absent or the upper end of the discharge prevention pin 55 is worn, creating a space 490 at the upper end of the vent 30, abnormal discharges may occur in the vent 30 during plasma-based processes in semiconductor equipment, depending on factors such as the gas pressure, voltage, and size (maximum distance or volume) of the space 490 within the reactor. This can induce events such as... Figure 1a and Figure 1b The electric arc shown prevents plasma processing from being carried out.

[0054] In order to suppress the above-mentioned abnormal discharge in the ceramic base 100, it is important to prevent the discharge prevention pin 55 from wearing out so as to prevent the creation of space 490 at the upper end of the pore 30, thereby preventing electrons from being accelerated in space 490.

[0055] Therefore, preferably, the discharge prevention pin 55 comprises an Al2O3-SiC composite material, for example, the Al2O3-SiC composite material may contain 3wt% to 10wt% SiC. Preferably, the Al2O3-SiC composite material has a volume resistivity of 1E15Ωcm or more at room temperature and a volume resistivity of 1E14Ωcm or more at a temperature of 200°C.

[0056] Table 1 below summarizes the arithmetic mean roughness (Ra), ten-point mean roughness (Rz), etching depth, and etching rate of various comparative materials (SiC, Al2O3+SiC mixture, and pure Al2O3 with more than 99.9% purity) under a specified plasma generation environment within a 10-minute etching time.

[0057] Table 1

[0058]

[0059] Typically, pure Al2O3 is a brittle material with high strength and high density. To achieve thermal shock resistance, a material mixed with SiC is used to prepare the discharge prevention pin 55. In particular, as shown in Table 1, the plasma etching rate of the discharge prevention pin 55 made from a mixture of Al2O3 (e.g., 90 wt% to 97 wt%) and SiC (e.g., 3 wt% to 10 wt%) can be in the range of 0.02 μm / min to 0.1 μm / min (e.g., 0.03 μm / min). Therefore, even in in-situ plasma processes such as dry etching, the etching rate is not high, thereby preventing the discharge prevention pin 55 in the pore 30 from being worn and preventing the formation of a space 490 at the upper end of the pore 30. In reactive ion etching (RIE) equipment, the etching rate is measured under normal process conditions for dry etching, but can be slightly modified according to the process conditions.

[0060] At this point, the volume resistivity of the discharge prevention pin 55 is above 1E15 Ωcm at room temperature and above 1E14 Ωcm at 200°C. Furthermore, by suppressing the potential difference in the upper end space 490 of the vent 30, electrons cannot be accelerated within the space 490, thus preventing abnormal discharge. This is because when the volume resistivity of the discharge prevention pin 55 is above 1E16 Ωcm, an arc can be generated by increasing the potential difference in the vent 30. When the volume resistivity of the discharge prevention pin 55 is below 1E14 Ωcm, the current concentrates on the discharge prevention pin 55, which can lead to changes in process characteristics (such as plasma etching) due to abnormal discharge.

[0061] Figure 5 This is an actual experimental photograph showing a clean state with no abnormal discharge around the pores 30 on the upper surface of the ceramic base 100 according to an embodiment of the present invention.

[0062] like Figure 5 As shown, for example, it has been confirmed that a ceramic base 100 of an embodiment of the present invention, which uses a material for making a discharge prevention pin 55 made of a mixture of Al2O3 (e.g., 90wt% to 97wt%) and SiC (e.g., 3wt% to 10wt%), maintains a clean state without abnormal discharge around the pores 30.

[0063] As described above, in the ceramic base 100 according to the present invention, as a material for the discharge prevention pin 55 of the pore 30, for example, a material in which 3 wt% to 10 wt% SiC is mixed in Al2O3 can be used to maintain the plasma etching rate in the range of 0.02 μm / min to 0.1 μm / min, and to maintain the volume resistivity of the material at room temperature at 1E15 Ωcm or more, and at a temperature of 200°C at 1E14 Ωcm or more, thereby improving the plasma resistance and increasing the lifespan of the ceramic base 100. That is, the discharge prevention pin 55 of the present invention will not wear due to the improved plasma resistance, and therefore will not form an electron acceleration space in the pores, thereby preventing abnormal discharge. In addition, by maintaining the volume resistivity of the above-mentioned material, the occurrence of a high potential difference that can induce abnormal discharge at high resistance can be prevented, and the increase of current that can induce abnormal discharge at low resistance can be prevented.

[0064] As described above, this invention has been illustrated with specific details and limited embodiments, such as specific constituent elements, and accompanying drawings. However, this is only provided to facilitate a more comprehensive understanding of the invention. The invention is not limited to the described embodiments, and various modifications and variations can be made by those skilled in the art without departing from the essential characteristics of the invention. Therefore, the concept of the invention should not be limited to the illustrated embodiments, and all technical ideas equivalent to or having equivalent variations to the claims described below should be interpreted as being included within the scope of the invention.

Claims

1. A ceramic base, characterized in that, include: The substrate has a cooling gas flow path for supplying cooling gas. An insulating board, fixed to the substrate, has pores extending through the thickness direction, and A discharge prevention pin is inserted into the air hole and extends along the length of the air hole; The discharge prevention pin comprises an Al2O3-SiC composite material, which has a volume resistivity of 1E14Ωcm or higher at a temperature of 200℃.

2. The ceramic base according to claim 1, characterized in that, The discharge prevention pin is made of a material with a volume resistivity in the range of 1E14Ωcm to 1E15Ωcm.

3. The ceramic base according to claim 1, characterized in that, The end cross-sectional area of ​​the discharge prevention pin is 50% to 90% of the cross-sectional area of ​​the vent.

4. The ceramic base according to claim 1, characterized in that, In the Al2O3-SiC composite material, the SiC content is 3wt% to 10wt%.

5. The ceramic base according to claim 1, characterized in that, The Al2O3-SiC composite material has a volume resistivity of 1E15Ωcm or higher at room temperature.

6. The ceramic base according to claim 1, characterized in that, The discharge prevention pin is inserted into the air hole with a diameter of less than 1 mm.

7. The ceramic base according to claim 1, characterized in that, The ceramic base includes an electrode layer located within the insulating plate. The electrode layer includes one or more of the following: electrostatic chuck electrode, high-frequency electrode, or heating wire.

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