Substrate processing equipment

Abstract

An example of a substrate processing apparatus includes: a susceptor; a shaft that supports the susceptor; a flow control ring that surrounds the susceptor while providing a gap relative to the susceptor; an exhaust pipe that is arranged directly above the flow control ring; a plate that is disposed above the susceptor; a chamber that surrounds the susceptor, the flow control ring, the exhaust pipe, and the plate; and a coupling that couples the shaft to the chamber, wherein at least a portion of the coupling is an insulator.

Description

Technical Field

[0001] Examples related to substrate processing apparatus are described. Background Art

[0002] Capacitively coupled plasma (CCP) is widely used in plasma processing. However, parasitic capacitance may be generated in the device, and voltage may be applied to some unintended parts. Such unexpected voltage application may cause power loss. For example, if a strong electric field is generated in a portion other than the perimeter of the bevel, the uniformity of the plasma may be deteriorated, and / or the etching rate may be reduced. Summary of the invention

[0003] Some examples described herein may address the above issues.Some examples described herein may provide a substrate processing apparatus that applies plasma processing to a portion of a substrate.

[0004] In some examples, a substrate processing device includes: a base; a shaft that supports the base; a flow control ring that surrounds the base while providing a gap relative to the base; an exhaust pipe that is arranged directly above the flow control ring; a plate that is disposed above the base; a chamber that surrounds the base, the flow control ring, the exhaust pipe and the plate; and a connecting portion that connects the shaft to the chamber, wherein at least a portion of the connecting portion is an insulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 is a configuration example of a substrate processing apparatus;

[0006] Figure 2 It is an enlarged view of the enclosed part;

[0007] Figure 3A is a circuit diagram showing an example of electrical connection;

[0008] Figure 3B is a circuit diagram showing another example of electrical connections;

[0009] Figure 4 shows the simulation results of the electromagnetic field;

[0010] Figure 5 Another simulation result of the electromagnetic field is shown;

[0011] Figure 6 is a cross-sectional view of a substrate processing apparatus related to another example; and

[0012] Figure 7 is a cross-sectional view of a substrate processing apparatus related to still another example. DETAILED DESCRIPTION

[0013] The substrate processing apparatus will be described with reference to the accompanying drawings. The same or similar elements may be denoted by the same symbols, and thus duplication of description may be omitted.

[0014] Figure 1 A construction example of a substrate processing device 10 is shown. The substrate processing device 10 can be set as a bevel processing device for a substrate. Bevel processing includes bevel etching, bevel deposition, and bevel film reforming. The substrate processing device 10 includes a chamber 12 used as a ground electrode. The chamber 12 is made of metal. In the chamber 12, a substrate as a processing object is placed on a susceptor 14. Since the geometry of the susceptor 14 is smaller than the substrate, the bevel protrudes from the susceptor 14. In other words, the entire bevel is exposed. The susceptor 14 is made of Al or Ti, for example.

[0015] The base 14 is supported by the shaft 16. According to one example, a wide portion 18 is provided, which is continuous with the shaft 16 and wider than the shaft 16. The wide portion 18 may be arranged outside the chamber 12. The portion of the chamber 12 surrounding the shaft 16 is referred to as a surrounding portion 12a. The bellows 20 is provided between the surrounding portion 12a and the wide portion 18. The bellows 20 is expanded and contracted by a force from the outside, thereby lowering or raising the base 14.

[0016] Figure 2 The bellows 20 maintains the vacuum inside the chamber 12 .

[0017] The wide portion 18 and the bellows 20 serve as a coupling portion for coupling the shaft 16 to the chamber 12. For example, at least a portion of the coupling portion may be an insulator. According to one example, the wide portion 18 may be an insulator. According to another example, the bellows 20 may be an insulator. Such an insulator material may be a low dielectric constant material having a dielectric constant less than 10. For example, the insulator is quartz, alumina, or a fluorine-containing resin. The combination of the wide portion 18 and the bellows 20 is an example of a coupling portion. In other examples, a coupling portion having any configuration may be provided that enables the base 14 to be lowered and raised and couples the shaft 16 to the chamber 12.

[0018] Figure 3A and 3B is a circuit diagram showing an example of one aspect of the electrical connection between the chamber 12 and the shaft 16. Separating the enclosure 12a and the shaft 16 creates a capacitor C1. Coupling the shaft 16 and the chamber 12 results in a first resistor R1, which is attributable to contact resistance or the like. Figure 3A A circuit is shown comprising a capacitor C1 and a first resistor R1 . Figure 3B A circuit is shown when at least a portion of the coupling portion is made of an insulator.

[0019] Thus, separating the surrounding portion 12a from the shaft 16 and selecting an insulator as at least a portion of the coupling portion enables the base 14 to be in a floating state. In other words, increasing the impedance value between the base 14 and the chamber 12 electrically separates the base 14 from the chamber 12.

[0020] Now back to the description Figure 1 A flow control ring (FCR) 30 is disposed adjacent to the susceptor 14. The FCR 30 surrounds the susceptor 14 while providing a gap relative to the susceptor 14. The FCR 30 may be, for example, a metal such as Al or Ti. According to an example, the bottom surface of the FCR 30 contacts the chamber 12, thereby grounding the FCR 30.

[0021] The exhaust pipe 32 is arranged just above the FCR 30. The exhaust pipe 32 may be formed in a circular shape in a plan view, similar to the FCR 30. The exhaust pipe 32 provides a passage for discharging a gas used in a process to the outside of the chamber 12. The exhaust pipe 32 may be made of, for example, ceramic or alumina.

[0022] The outer plate 40 is placed on the exhaust pipe 32. The inner plate 42 is placed on the outer plate 40. According to an example, the outer plate 40 surrounds the inner plate 42 and is disposed directly above the FCR 30. According to an example, the inner plate 42 is disposed directly above the base 14. A through hole may be disposed in the center of the inner plate 42. The outer plate 40 and the inner plate 42 are sometimes collectively referred to as plates.

[0023] The outer plate 40 and the inner plate 42 constitute one plate. They may be separable or inseparable. For example, the inner plate 42 is an insulator and the outer plate 40 is a metal. The inner plate 42 may be a low dielectric constant material. The low dielectric constant material is, for example, quartz, alumina, or a fluorine-containing resin. The outer plate 40 may be an electrode to which a high-frequency wave is applied.

[0024] The chamber 12 surrounds the susceptor 14, the FCR 30, the exhaust pipe 32, the outer plate 40, and the inner plate 42. Gas sources 50 and 52 are provided outside the chamber 12. According to an example, the gas source 50 supplies an inert gas to the through-holes of the inner plate 42, thereby generating a radial gas flow, which is between the inner plate 42 and the susceptor 14 in a plan view. This gas flow suppresses the generation of a large amount of plasma between the inner plate 42 and the susceptor 14. Also, the gas source 52 supplies a reactive gas to the gap between the susceptor 14 and the FCR 30 from the lower side. This gas flow enables etching near the oblique angle of the substrate.

[0025] Such a gas flow is an example. According to other examples, any gas source and gas flow can be used, which can supply a gas that allows plasma to be generated near the oblique angle. Therefore, the gas can be supplied from the upper side and can also be supplied from the lower side.

[0026] Figure 4The simulation results of the electromagnetic field in the model in which the base is set to float are shown. In the red area, the electric field strength is high, while in the blue area, the electric field strength is low. The simulation adopts a model in which the substrate is set in a substrate processing device. Applying high-frequency power to the outer plate 40 enhances the electric field strength in the space between the outer plate 40 and the FCR30. On the other hand, because the base is set to float, the RF loss relative to the base 14 is reduced, thereby reducing the electric field strength between the base 14 and the inner plate 42. Selecting a low dielectric constant material as the inner plate 42 also helps to reduce the electric field strength between the base 14 and the inner plate 42. The synthetic impedance is greater than 500 ohms, and its path is from the plate through the base 14, the shaft and the coupling to the chamber 12, thus helping to reduce abnormal discharge.

[0027] Figure 5 based on Figure 4 The model in shows the simulation result of the electromagnetic field when the inner plate 42 is metal and the base 14 is grounded metal. In this case, because a strong electric field is generated between the inner plate 42 and the base 14, abnormal discharge can be conceived.

[0028] Therefore, a hardware configuration is adopted that enhances the impedance at the portion where plasma is not desired to be generated. Thus, the electric field strength is reduced, and RF is effectively supplied to the area intended to generate plasma. Methods for reducing the electric field strength include using a low dielectric constant material and having a floating potential at the relevant portion. Figure 1 The configurations of 3 are examples. Figure 1 The substrate processing apparatuses of different configurations can also reduce abnormal discharge and provide stable discharge in a similar manner.

[0029] Figure 6 1 is a cross-sectional view of a substrate processing apparatus related to another example. In this example, the enclosure 12a is made of an insulator so that the base 14 is floating. The enclosure 12a is, for example, quartz, alumina, or a fluorine-containing resin. In this case, the enclosure 12a is distinguished from the metal chamber 12. Selecting a low dielectric constant material for the enclosure 12a can widen the electrical distance between the metal chamber 12 and the shaft 16, and the metal chamber 12 and the shaft 16 are electrically isolated. Therefore, the impedance of the path from the base 14 to the chamber 12 can be further increased.

[0030] Figure 730 is a cross-sectional view of a substrate processing apparatus related to yet another example. The FCR 30 includes a metal portion 30a in contact with the chamber 12 and an insulator portion 30b located just below the exhaust pipe 32. According to an example, the metal portion 30a and the insulator portion 30b are exposed at the top surface of the FCR 30, and only the metal portion 30a is exposed at the bottom surface of the FCR 30. The top surface of the FCR 30 may be a planar surface so as not to interfere with the gas flow to the exhaust pipe 32. For example, the insulator portion 30b is quartz, alumina, or a fluorine-containing resin.

[0031] The exhaust pipe 32 is an insulator and is made of, for example, quartz, alumina, or fluorine-containing resin.

[0032] Connecting the outer plate 40 and the FCR30 with low impedance effectively provides RF energy to the path. However, the generation of a high electric field between the FCR30 and the exhaust pipe 32 causes a high concentration of plasma at this portion. Therefore, as described above, the insulator portion 30b is provided at the FCR30. Thus, although the outer plate 40 and the FCR30 are connected with low impedance, the impedance of the exhaust pipe 32 and the FCR30 can be increased. Therefore, the discharge at the portion directly below the exhaust pipe 32 can be reduced.

[0033] When the board is placed over the base 14 and FCR30, the impedance can be defined as follows:

[0034] (1) a first impedance, which is the impedance of the path through the board and the base 14,

[0035] (2) a second impedance, which is the impedance of the path through the board and FCR 30, and

[0036] (3) A third impedance, which is the impedance of a path passing through the exhaust pipe 32 .

[0037] According to an example, the second impedance among the first to third impedances may be minimized. Thus, generating local plasma between the outer plate 40 and the FCR 30 allows plasma processing of an oblique corner of the substrate.

[0038] For example, if the distance between the inner plate 42 and the base 14 is d1, the area facing the inner plate 42 and the base 14 is S1, the dielectric constant of the material placed between the inner plate 42 and the base 14 is ε1, and the plasma excitation frequency applied to the outer plate 40 is f1, the first impedance d1 / 2πf1ε1S1 can be set to be higher than 50 ohms. To achieve this, for example, quartz or the like can be used as the inner plate 42, or d1 and S1 can be adjusted. Note that if f1 is 13.56 MHz and ε1 is the dielectric constant of air, d1 / S1 is set to be higher than 0.3777.

[0039] For example, if the distance between the exhaust pipe 32 and the FCR 30 is d2, the area of ​​the exhaust pipe 32 and the FCR 30 facing each other is S2, the dielectric constant of the material placed between the exhaust pipe 32 and the FCR 30 is ε2, and the plasma excitation frequency applied to the outer plate 40 is f2, the third impedance d2 / 2πf2ε2S2 can be set to be higher than 50 ohms. To achieve this, for example, quartz can be used as the exhaust pipe 32, d2 and S2 can be adjusted, or quartz can be used as Figure 7 Note that if f2 is 13.56 MHz and ε2 is the dielectric constant of air, d2 / S2 is set to be higher than 0.3777. Another third impedance (which is the impedance of the path through the exhaust pipe 32 and the chamber 12) may be set to be higher than 50 ohms.

[0040] According to another example, d1 / 2πf1ε1S1 may be set to be higher than 500 ohms, d2 / 2πf2ε2S2 may be set to be higher than 500 ohms, and another third impedance may be set to be higher than 500 ohms. In other examples, other values ​​may be selected.

[0041] Therefore, while the first impedance and the third impedance are set to high values, the second impedance is set to less than 50 ohms, for example, so that sufficient plasma can be generated between the outer plate 40 and the FCR 30. The portion with potential abnormal discharge varies depending on the configuration of the device. Therefore, any configuration can be adopted in which the impedance in the space where the bevel is placed is set to low and the impedance in other spaces is set to high.

Claims

1. A substrate processing device, comprising: Pedestal; the shaft, its supporting base; a flow control ring surrounding the base while providing clearance relative to the base; an exhaust pipe arranged directly above the flow control ring; a plate disposed above the base; a chamber surrounding the base, flow control ring, exhaust tube, and plate; and a coupling portion coupling the shaft to the chamber, wherein at least a portion of the coupling portion is an insulator, The plate includes an inner plate and an outer plate, wherein the inner plate is arranged directly above the base and is an insulator, and the outer plate surrounds the inner plate and is arranged directly above the flow control ring and is made of metal.

2. The substrate processing apparatus according to claim 1, wherein: The coupling portion includes a wide portion which is continuous with and wider than the shaft and is arranged outside the chamber, and a bellows which is provided between a surrounding portion which surrounds the shaft in the chamber and the wide portion.

3. The substrate processing apparatus according to claim 1 or 2, wherein: The insulator is quartz, alumina or fluorine-containing resin.

4. The substrate processing apparatus according to claim 1 or 2, wherein: The combined impedance of the path from the plate through the base, shaft and coupling to the chamber is greater than 500 ohms.

5. The substrate processing apparatus according to claim 1, wherein: The insulator surrounds the shaft and is disposed between the chamber and the shaft.

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