Electrode for capacitively coupled plasma generator, capacitively coupled plasma generator including the same, and method for adjusting uniformity of capacitively coupled plasma

Abstract

Disclosed are an electrode for a capacitively coupled plasma generator, a capacitively coupled plasma generator including the same, and a method for adjusting capacitively coupled plasma uniformity. The electrode for the capacitively coupled plasma generator can include a first plate electrode, a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode, and a power supply unit that applies RF (radio frequency) power to the first and second plate electrodes. The power supply unit can apply RF power of different phases to the first and second plate electrodes.

Description

[Technical Field]

[0001] The present invention relates to an electrode for a capacitively coupled plasma generation device, a capacitively coupled plasma generation device including the same, and a method for adjusting the uniformity of capacitively coupled plasma. [Background technology]

[0002] Capacitively coupled plasma (CCP), one of the most common types of industrial plasma generators, generates plasma by supplying RF power to one of two opposing electrodes and injecting a reactor gas at subatmospheric or atmospheric pressure. While a single electrode has typically been used in CCP, the rapid increase in integration density of integrated circuits has led to active research into multi-electrode systems to improve plasma uniformity or intentionally maintain non-uniformity. Due to drawbacks of multi-electrode systems, for example, when the electrode to which RF power is applied is divided into a first electrode and a second electrode, the two electrodes must be electrically isolated by an insulator. However, in such an insulator section, the spatial distribution of the electric field generated by the RF power, especially the RF voltage, becomes discontinuous, making it difficult to ensure uniformity in the plasma process. Therefore, there is a need for a method to improve plasma uniformity in the insulator section and for a plasma generator with the ability to intentionally adjust this uniformity. Summary of the Invention [Problem to be solved by the invention]

[0003] The present invention aims to provide a mechanical structure of a multi-electrode that improves the non-uniformity of plasma generated in the insulator sections that are necessary to maintain electrical independence between the multi-electrodes, and a method for adjusting the plasma uniformity of a capacitively coupled plasma source by adjusting the phase of RF power applied to the multi-electrode. [Means for solving the problem]

[0004] In one aspect, the present invention provides an electrode for a capacitively coupled plasma generator, comprising: a first plate electrode; a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode; and a power supply unit that applies RF (radio-frequency) power to the first plate electrode and the second plate electrode.

[0005] In one embodiment, the power supply unit can apply RF powers of different phases to the first plate electrode and the second plate electrode.

[0006] In one embodiment, the power supply unit can apply RF power of opposite phases to the first plate electrode and the second plate electrode.

[0007] In one embodiment, the power supply unit may include a circuit that can correct the phases of two or more electric powers generated from a single power source and apply them differently to the first plate electrode and the second plate electrode.

[0008] In one embodiment, the power supply unit may further include a variable element between one or more of the circuit and the first plate electrode or the circuit and the second plate electrode, capable of controlling the relative magnitude of the RF power applied to the first plate electrode and the second plate electrode, respectively.

[0009] In one embodiment, the power supply unit can control the magnitude of the RF power applied to the second plate electrode so that it is greater than the magnitude of the RF power applied to the first plate electrode.

[0010] In one embodiment, the first plate electrode may be a circular electrode, and the second plate electrode may be a ring electrode.

[0011] In one embodiment, the electrode assembly may further include a ring-shaped insulating portion positioned between the first plate electrode and the second plate electrode to insulate them.

[0012] In another aspect, the present invention provides a capacitively coupled plasma generator including an electrode for the capacitively coupled plasma generator, a substrate formed opposite the electrode for the capacitively coupled plasma generator, a chamber that accommodates the electrode for the capacitively coupled plasma generator and the substrate, and a gas supply unit that can supply a discharge gas to the chamber.

[0013] In yet another aspect, the present invention provides a capacitively coupled plasma uniformity adjustment method, which includes applying RF powers of different phases to a first plate electrode and a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode.

[0014] In one embodiment, the capacitively coupled plasma uniformity adjustment method can apply RF power to the first plate electrode and the second plate electrode in opposite phases.

[0015] In one embodiment, applying the RF powers of different phases can be achieved by modifying the phases of two or more powers generated from a single power source and applying them differently to the first plate electrode and the second plate electrode.

[0016] In one embodiment, the capacitively coupled plasma uniformity adjustment method may further include controlling the magnitude of RF power applied to the first plate electrode and the second plate electrode, respectively.

[0017] In one embodiment, the capacitively coupled plasma uniformity adjustment method can control the magnitude of the RF power applied to the second plate electrode to be greater than the magnitude of the RF power applied to the first plate electrode.

[0018] In one embodiment, the first plate electrode may be a circular electrode, and the second plate electrode may be a ring electrode.

[0019] In one embodiment, the capacitively coupled plasma uniformity adjustment method may further include insulating the first plate electrode from the second plate electrode. [Effects of the Invention]

[0020] The multiple electrodes and multiple power supply units for the capacitively coupled plasma generating apparatus according to the present invention can generate relatively uniform plasma even near the insulating portion compared to the multiple electrodes configured in the prior art.

[0021] According to an embodiment of the present invention, a capacitively coupled plasma generation apparatus including a device such as a multi-output port impedance matching device including variable elements that can respectively correct or adjust the phase of RF power, or including variable elements (variable capacitors, variable inductors) that can control the relative magnitude of RF voltage or current, can ensure relatively uniform plasma formation and uniform process results.

[0022] By appropriately adjusting the value of a variable element included in a capacitively coupled electrode according to an embodiment of the present invention, the plasma uniformity can be relatively improved or adjusted at the insulating portion of the electrode used to generate the capacitively coupled plasma. [Brief explanation of the drawings]

[0023] [Figure 1a] 1 is a diagram illustrating an electrode for a capacitively coupled plasma generating device according to an embodiment of the present invention. [Figure 1b] 1 is a diagram illustrating an electrode for a capacitively coupled plasma generating device according to an embodiment of the present invention. [Figure 2] 1 is a perspective view schematically illustrating an embodiment of a capacitively coupled plasma generation apparatus according to an embodiment of the present invention. [Figure 3] 1 is a flow chart illustrating a capacitively coupled plasma uniformity adjustment method according to an embodiment of the present invention. [Figure 4] 4 is a diagram showing the distribution of an electric field of an electrode for a capacitively coupled plasma apparatus according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. The present invention may be modified in various ways and may have various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the present invention to the particular disclosed form, but it should be understood that the present invention encompasses all modifications, equivalents, and alternatives within the spirit and technical scope of the present invention. Similar reference numerals are used to refer to similar components throughout the drawings. In the accompanying drawings, the dimensions of structures are exaggerated to clarify the present invention.

[0025] The terms used in this application are used only to describe specific embodiments and are not intended to limit the present invention. The singular expressions include the plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "have" are intended to specify the presence of features, numbers, steps, operations, components, or combinations thereof described in the specification, and should be understood not to preclude the presence or additional possibility of one or more other features, steps, numbers, operations, components, or combinations thereof.

[0026] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms as defined in commonly used dictionaries should be interpreted to have a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined in this application.

[0027] FIG. 1a is a diagram showing an electrode for a capacitively coupled plasma generating device according to an embodiment of the present invention.

[0028] Referring to FIG. 1a, an electrode 1 for a capacitively coupled plasma generator according to an embodiment of the present invention may include a first plate electrode 11, a second plate electrode 12 positioned around the first plate electrode 11 on the same plane as the first plate electrode 11, and a power supply unit 20 that applies RF (radio-frequency) power to the first plate electrode 11 and the second plate electrode 12.

[0029] The first plate electrode 11 and the second plate electrode 12 function as electrodes in a capacitively coupled plasma generator, with the second plate electrode 12 surrounding the first plate electrode 11. In the context of this specification, "plate-shaped" refers to a shape that is significantly thinner than its width and has virtually no curvature. A plate electrode is an electrode having a plate shape that can provide electrical potential energy or a potential difference over a relatively large area when power is applied. While FIG. 1a illustrates the first plate electrode 11 and the second plate electrode 12 as being circular and ring-shaped, respectively, the scope of the present invention is not necessarily limited thereto. In one embodiment, the first plate electrode 11 may be a circular electrode, and the second plate electrode 12 may be a ring-shaped electrode.

[0030] Meanwhile, the electrode 1 for the capacitively coupled plasma generator according to an embodiment of the present invention may include additional electrodes in addition to the first plate electrode 11 and the second plate electrode 12. In one embodiment, when the electrode 1 for the capacitively coupled plasma generator according to an embodiment of the present invention includes three or more electrodes, and when a specific first plate electrode and a specific second plate electrode are selected from the three or more electrodes, the description of the electrode for the capacitively coupled plasma generator according to an embodiment of the present invention may be applied. In one embodiment, when the electrode 1 for the capacitively coupled plasma generator according to an embodiment of the present invention includes three or more electrodes, and when a specific first plate electrode and a specific second plate electrode are selected from the three or more electrodes, the description of the electrode for the capacitively coupled plasma generator according to an embodiment of the present invention may be applied to all of the electrodes, respectively.

[0031] The power supply unit 20 is a component that functions as a power source capable of providing electrical potential energy or a potential difference to the first plate electrode 11 and the second plate electrode 12. When the first plate electrode 11 and the second plate electrode 12 are used in a capacitively coupled plasma generator, the function of the power source can be performed by applying radio frequency (RF) power. In one embodiment, the power supply unit 20 can apply RF power of different phases to the first plate electrode 11 and the second plate electrode 12. In one embodiment, the power supply unit 20 can apply RF power of opposite phases to the first plate electrode 11 and the second plate electrode 12.

[0032] The solution to one problem of the present invention can be based on the discovery that when RF power of different phases is applied to the first plate electrode 11 and the second plate electrode 12 as described above, the change in electrical potential energy generated in the insulating portion due to the interference phenomenon between the RF power applied to the first plate electrode 11 and the second plate electrode 12 can have relative continuity, and in this case, the continuity can be adjusted by adjusting the magnitude of the RF power applied to the first plate electrode 11 and the second plate electrode 12.

[0033] To perform the above functions, the power supply unit 20 may be configured to apply RF power of different phases or opposite phases. In one embodiment, the power supply unit 20 includes two or more power sources, each of which can apply RF power of different phases or opposite phases to the first plate electrode 11 and the second plate electrode 12. In one embodiment, the power supply unit 20 may include a circuit 20C that can adjust the phases of two or more powers generated from a single power source 20P and apply them differently to the first plate electrode 11 and the second plate electrode 12. This allows the power supply unit 20 to apply RF power of different phases to the first plate electrode 11 and the second plate electrode 12. This also allows the power supply unit 20 to apply RF power of opposite phases to the first plate electrode 11 and the second plate electrode 12. In one embodiment, the circuit 20C may include a device such as a multi-output port impedance matching device including a variable element.

[0034] Although FIG. 1a illustrates the inclusion of one power source 20P and one circuit 20C for correcting the phases of two or more powers generated therefrom, this is merely an example, and the scope of the present invention is not limited to the number of power sources 20P and circuits 20C. For example, FIG. 1b illustrates another embodiment of an electrode for a capacitively coupled plasma generator according to an embodiment of the present invention. Referring to FIG. 1b, the electrode 1 for a capacitively coupled plasma generator according to an embodiment of the present invention may include two or more circuits 20C for correcting the phases of two or more powers generated from two or more power sources 20P. While FIG. 1b illustrates two power sources 20P and two circuits 20C, this is merely to disclose that multiple power sources 20P and circuits 20C may be included, and the number of power sources 20P and circuits 20C is not limited to two.

[0035] Meanwhile, as described above, one solution to the problem of the present invention is based on the discovery that, when RF powers of different phases are applied to the first plate electrode 11 and the second plate electrode 12, the change in electrical potential energy generated in the insulating portion due to the interference phenomenon between the RF powers applied to the first plate electrode 11 and the second plate electrode 12 can have a relative continuity. In this case, the continuity can be adjusted by adjusting the magnitude of the RF power applied to the first plate electrode 11 and the second plate electrode 12. To achieve this, in one embodiment, the power supply unit 20 may further include variable elements 21 and 22 between the circuit 20C and the first plate electrode 21 or between the circuit 20C and the second plate electrode 22, which can control the relative magnitude of the RF power applied to the first plate electrode 21 and the second plate electrode 22, respectively. In one embodiment, the variable elements 21 and 22 may include variable capacitors. In another embodiment, the variable elements 21 and 22 may include variable inductors. In one embodiment, the power supply unit 20 can control the magnitude of the RF power applied to the second plate electrode 22 to be greater than the magnitude of the RF power applied to the first plate electrode 21. In one embodiment, the power supply unit 20 can control the magnitude of the RF power applied to the second plate electrode 22 to be greater than the magnitude of the RF power applied to the first plate electrode 21 through the variable elements 21, 22.

[0036] In one embodiment, the electrode assembly may further include a ring-shaped insulating part 30 positioned between the first plate electrode 21 and the second plate electrode 22 to provide insulation therebetween.

[0037] As described above, the electrode for the capacitively coupled plasma generating device according to the embodiment of the present invention can generate relatively uniform plasma even in the insulating portion.

[0038] FIG. 2 is a perspective view schematically illustrating an embodiment of a capacitively coupled plasma generation device according to an embodiment of the present invention.

[0039] Referring to FIG. 2, a capacitively coupled plasma generator 5 according to an embodiment of the present invention may include an electrode 1′ for a capacitively coupled plasma generator, a substrate 40 formed opposite the electrode 1′ for the capacitively coupled plasma generator, a chamber 50 accommodating the electrode 1′ for the capacitively coupled plasma generator and the substrate 40 therein, and a gas supply unit 60 capable of supplying a discharge gas to the chamber 50.

[0040] The electrode 1' for a capacitively coupled plasma generator may be or may include the electrode 1 for a capacitively coupled plasma generator according to the embodiment of the present invention described in the above aspects. In Fig. 2, the first and second plate electrodes and the ring-shaped insulator of the electrode 1' for a capacitively coupled plasma generator are shown as being arranged horizontally inside the chamber 50, and the other components are shown as being arranged outside the chamber 50, but this is merely an example, and the orientation and arrangement of the electrode 1' for a capacitively coupled plasma generator are not limited thereto.

[0041] The electrode 1' for the capacitively coupled plasma generator is a member capable of generating plasma from electrical potential energy or a potential difference. Therefore, once the orientation of the electrode 1' for the capacitively coupled plasma generator is determined, the orientation of the substrate 40 can be determined by forming it opposite the electrode 1'. Although the substrate 40 is shown in FIG. 2 as not being electrically connected to other members, this is merely an example to avoid confusion in the drawing, and in one embodiment, the substrate 40 may be grounded.

[0042] The chamber 50 is a member capable of accommodating the electrode 1' for the capacitively coupled plasma generator and the substrate 40. As is well known in the art, a capacitively coupled plasma generator can generate plasma in a discharge chamber at atmospheric pressure or below atmospheric pressure, and the chamber 50 can perform the function of at least positioning the electrode 1' for the capacitively coupled plasma generator and the substrate 40 within the discharge chamber.

[0043] The gas supply unit 60 is a member capable of supplying the discharge gas to the chamber 50 .

[0044] As described above, the capacitively coupled plasma generating apparatus according to the embodiment of the present invention can apply a relatively uniform plasma to a substrate.

[0045] FIG. 3 is a flow chart illustrating a capacitively coupled plasma uniformity adjustment method according to an embodiment of the present invention.

[0046] Referring to FIG. 3, a capacitively coupled plasma uniformity adjustment method 100 according to an embodiment of the present invention may include applying RF powers of different phases to a first plate electrode and a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode (S110).

[0047] The description of the capacitively coupled plasma uniformity adjustment method 100 may be applied in the same or similar manner to the description of the capacitively coupled plasma generation device according to the above-mentioned embodiment of the present invention or the capacitively coupled plasma generation device according to the embodiment of the present invention.

[0048] Therefore, the step of applying RF powers of different phases (S110) may be a step based on the discovery that, when RF powers of different phases are applied to the first plate electrode and the second plate electrode, as described in the electrode for a capacitively coupled plasma generating device according to an embodiment of the present invention, the change in electrical potential energy generated in the insulating portion may have relative continuity due to the interference phenomenon between the RF powers applied to the first plate electrode and the second plate electrode, and in this case, the continuity can be adjusted by adjusting the magnitude of the RF power applied to the first plate electrode and the second plate electrode.

[0049] Furthermore, when performing the step of applying RF powers of different phases (S110), as described in the electrode for a capacitively coupled plasma generation device according to an embodiment of the present invention, RF powers of opposite phases may be applied to the first plate electrode and the second plate electrode. Also, in one embodiment, applying RF powers of different phases may involve modifying the phases of two or more powers generated from a single power source and applying them to the first plate electrode and the second plate electrode differently.

[0050] In one embodiment, the capacitively coupled plasma uniformity adjustment method 100 may further include controlling the magnitude of the RF power applied to the first plate electrode and the second plate electrode, respectively. In one embodiment, the capacitively coupled plasma uniformity adjustment method may control the magnitude of the RF power applied to the second plate electrode to be greater than the magnitude of the RF power applied to the first plate electrode.

[0051] In one embodiment, the first plate electrode may be a circular electrode, and the second plate electrode may be a ring electrode.

[0052] In one embodiment, the capacitively coupled plasma uniformity adjustment method may further include insulating the first plate electrode from the second plate electrode.

[0053] As described above, the method for adjusting the uniformity of a capacitively coupled plasma according to an embodiment of the present invention can relatively improve or adjust the uniformity of the plasma at the insulating portion of the electrode used to generate the capacitively coupled plasma.

[0054] Hereinafter, embodiments of the present invention will be described. However, the embodiments described below are merely some of the embodiments of the present invention, and the scope of the present invention is not limited to the following embodiments.

[0055] Fabrication of electrodes for capacitively coupled plasma devices

[0056] The device comprises a circular first plate electrode, an insulating portion surrounding the first plate electrode to insulate it, and an annular second plate electrode formed along the insulating portion. A power supply is connected to the first plate electrode and the second plate electrode, and the power supply is provided with a circuit capable of correcting the phase from an RF power source and a variable element capable of adjusting the magnitude of RF power applied to each of the first and second plate electrodes. RF powers of opposite phases (180° phase difference) are applied to the first and second plate electrodes, and in particular, the magnitude of the RF power applied to the second plate electrode is adjusted to be greater than the magnitude of the RF power applied to the first plate electrode.

[0057] Fabrication and operation of a capacitively coupled plasma device

[0058] The electrode for the capacitively coupled plasma device is placed in a chamber, a substrate is placed facing the electrode, and the substrate is grounded. A discharge gas is injected into the chamber, and RF power is applied to the electrode to generate plasma in the discharge gas.

[0059] Electric field distribution

[0060] 4 is a diagram showing the distribution of an electric field when RF power of the same phase (left) and opposite phase (right) is applied to the first and second plate electrodes of the capacitively coupled plasma device according to an embodiment of the present invention. Referring to FIG. 4, it can be seen that when opposite phases are applied, a strong electric field distribution is generated even in the insulating portion between the first and second plate electrodes.

[0061] Although the present invention has been described above with reference to preferred embodiments, it should be understood that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the appended claims. [Explanation of symbols]

[0062] 1, 1': Electrodes for capacitively coupled plasma generator 5: Capacitively coupled plasma generator 11: First plate electrode 12: Second plate electrode 20: Power supply section 20P: Power source 20C:Circuit 21, 22: Variable element 30: Insulation section 40: Circuit board 50: Chamber 60: Gas supply section 100: Capacitively coupled plasma uniformity adjustment method

Claims

1. a first plate electrode; a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode; a power supply unit that applies RF (radio frequency) power to the first plate electrode and the second plate electrode; Including, The power supply unit applies RF power of different phases to the first plate electrode and the second plate electrode.

2. 2. The electrode for a capacitively coupled plasma generator according to claim 1, wherein the power supply unit applies RF powers of opposite phases to the first plate electrode and the second plate electrode.

3. 2. The electrode for a capacitively coupled plasma generator according to claim 1, wherein the power supply unit includes a circuit that can correct the phases of two or more electric powers generated from a single power source and apply them differently to the first plate electrode and the second plate electrode.

4. 2. The electrode for a capacitively coupled plasma generation device according to claim 1, wherein the power supply unit further includes a variable element capable of controlling the relative magnitude of RF power applied to the first plate electrode and the second plate electrode, respectively, at one or more between the circuit and the first plate electrode or between the circuit and the second plate electrode.

5. 5. The electrode for a capacitively coupled plasma generator according to claim 4, wherein the power supply unit controls the magnitude of the RF power applied to the second plate electrode so that the magnitude of the RF power applied to the first plate electrode is greater than the magnitude of the RF power applied to the second plate electrode.

6. the first plate electrode is a circular electrode, The electrode for a capacitively coupled plasma generator according to claim 1 , wherein the second plate electrode is a ring electrode.

7. The electrode for a capacitively coupled plasma generator according to claim 6 , further comprising an annular insulating portion positioned between the first plate electrode and the second plate electrode to insulate them.

8. An electrode for a capacitively coupled plasma generator according to any one of claims 1 to 7; a substrate formed opposite to the electrode for the capacitively coupled plasma generator; a chamber for accommodating the capacitively coupled plasma generating electrode and the substrate; and a gas supply unit capable of supplying a discharge gas to the chamber; A capacitively coupled plasma generating device comprising:

9. A method for adjusting capacitively coupled plasma uniformity, comprising applying RF powers of different phases to a first plate electrode and a second plate electrode positioned around the first plate electrode on the same plane as the first plate electrode.

10. The capacitively coupled plasma uniformity adjustment method according to claim 9 , wherein RF powers of opposite phases are applied to the first plate electrode and the second plate electrode.

11. 10. The capacitively coupled plasma uniformity adjustment method of claim 9, wherein applying RF powers of different phases involves modifying the phases of two or more powers generated from a single power source and applying them differently to the first plate electrode and the second plate electrode, respectively.

12. The capacitively coupled plasma uniformity adjusting method of claim 9 , further comprising controlling the magnitude of RF power applied to the first plate electrode and the second plate electrode, respectively.

13. The capacitively coupled plasma uniformity adjusting method according to claim 12 , wherein the magnitude of the RF power applied to the second plate electrode is controlled to be greater than the magnitude of the RF power applied to the first plate electrode.

14. the first plate electrode is a circular electrode, The capacitively coupled plasma uniformity adjusting method according to claim 9 , wherein the second plate electrode is a ring electrode.

15. The capacitively coupled plasma uniformity adjustment method of claim 14 , further comprising insulating the first plate electrode from the second plate electrode.

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