Substrate processing apparatus

Abstract

A substrate processing apparatus includes a processing chamber, a reaction space provided in the processing chamber, and a substrate inlet through which a substrate enters or exits; a susceptor disposed inside the processing chamber and supporting the substrate; a gas injector disposed on an opposite surface of the susceptor to inject a gas toward the substrate; a valve that opens and closes the substrate inlet; and a control electrode formed on the valve. The control electrode is vertically driven.

Description

Technical Field

[0001] This disclosure relates to a plasma processing apparatus, and more specifically, to a substrate processing apparatus capable of providing a processing chamber within the entire reaction space in a uniform processing environment. Background Technology

[0002] A typical substrate processing apparatus may include, for example, a processing chamber and a transfer chamber, wherein the substrate is processed using plasma in the processing chamber, and the substrate is loaded in the transfer chamber before processing and unloaded after processing in the transfer chamber.

[0003] In the case of a processing chamber, a slit is formed in a sidewall, and the substrate can be loaded and unloaded through the slit. Generally, the slit can be opened or closed by a slit valve located outside the slit or outside the chamber.

[0004] When performing substrate processing operations, the interior of the processing chamber, that is, the reaction space, should be maintained in a process environment such as a vacuum. Furthermore, a uniform processing environment should be applied throughout the entire reaction space.

[0005] Generally, the reaction space has an opening connected to the slit, through which the substrate is loaded or unloaded, and the slit is opened and closed by an external slit valve. Therefore, even when the slit is closed by the external slit valve, an empty space is formed between the slit valve and the opening.

[0006] Empty spaces can be connected to reaction spaces. Therefore, reaction spaces can be asymmetrically formed from empty spaces. Asymmetric reaction spaces may make it difficult to establish an overall inhomogeneous processing environment.

[0007] When plasma is generated in the reaction space, it may be difficult to distribute the plasma uniformly within the reaction space due to the influence of empty space. Therefore, it may be difficult to perform etching and deposition uniformly across the entire surface of the substrate.

[0008] In the deposition of plasma thin films, film uniformity can be affected by various factors, such as chamber structural asymmetry, substrate temperature non-uniformity, gas flow pattern formed by the pump, plasma non-uniformity, and similar factors. Specifically, local plasma non-uniformity can be affected by chamber structural asymmetry and electrical characteristics, as well as gas flow pattern formed by the pump.

[0009] In plasma processing, even when using valves with internal side surfaces (forming part of the internal side surface of the chamber) to improve structural azimuth asymmetry, localized process inhomogeneities still exist. For example, in a valveless environment, the interior of the chamber is a perfectly symmetrical environment. However, the necessary substrate inlets can be positioned to make it difficult to achieve perfect symmetry of the chamber. That is, even when the valve provides an internal side surface that forms part of the internal side surface of the chamber, 100% symmetry may be difficult to achieve due to the O-rings formed in the portions where the valve and chamber contact each other. Furthermore, because the electrical characteristics of the valve and the chamber differ from each other, the radio frequency (RF) current does not flow symmetrically in the azimuth direction, leading to localized process inhomogeneities. Therefore, a method is needed to control the localized inhomogeneities caused by differences in electrical characteristics. Summary of the Invention

[0010] The present disclosure aims to control local process non-uniformity of a substrate by inserting a control electrode adjacent to the inner sidewall of the chamber to apply power to the control electrode.

[0011] The present disclosure aims to provide a uniform process environment in the reaction space by using a chamber-integrated slit valve to prevent the reaction space from connecting to the slit during plasma semiconductor processing on a substrate. However, remaining localized process inhomogeneities are controlled using control electrodes formed at the opening / closing blades of the slit valve.

[0012] The present disclosure aims to symmetrically form the reaction space of the substrate processing apparatus when performing a semiconductor process on a substrate, and to uniformly perform the process on the entire surface of the substrate by making the plasma process environment uniform in the reaction space.

[0013] The present disclosure aims to control local process non-uniformity of a substrate by inserting a valve, providing an internal side surface (part of the internal side surface forming a chamber), and connecting the valve to an impedance circuit to change the electrical characteristics.

[0014] A substrate processing apparatus according to an example embodiment includes a processing chamber providing a reaction space within the processing chamber, and including a substrate inlet through which a substrate enters or exits; a base disposed inside the processing chamber and supporting the substrate; a gas injector disposed on an opposing surface of the base for injecting gas toward the substrate; a valve for opening and closing the substrate inlet; and a control electrode formed on the valve. In the example embodiment, the control electrode may be vertically driven.

[0015] In an example embodiment, the valve may include: a blade that opens and closes the substrate inlet and has an internal surface that forms part of the internal side surface of the processing chamber; and a drive unit that allows the blade to rise and fall. A control electrode may be formed on the blade.

[0016] In an example implementation, the blade can be selectively grounded or connected to an impedance circuit via a first switch.

[0017] In an example implementation, the impedance circuit may include LC circuits connected in parallel or in series with each other. The capacitors in each of the LC circuits may be variable.

[0018] In an example implementation, the control electrode may be connected to a power supply unit.

[0019] In an example implementation, the power supply unit may include at least one of a positive DC power supply, a negative DC power supply, and an RF power supply.

[0020] In an example embodiment, the substrate processing apparatus may further include: a second switch configured to connect to the power supply unit or ground and to the control electrode, wherein the second switch is selectively connected to at least one of the positive DC power supply, the negative DC power supply and the RF power supply.

[0021] A substrate processing apparatus according to an example embodiment includes: a processing chamber providing a reaction space within the processing chamber; a base disposed within the processing chamber and supporting a substrate; a gas injector disposed on an opposing surface of the base to inject gas toward the substrate; and a valve providing an inner side surface forming part of an inner side surface of the processing chamber and opening and closing a substrate inlet of the processing chamber, wherein the valve includes: a blade opening and closing the substrate inlet and having the inner side surface forming part of the inner side surface of the processing chamber; and a drive unit allowing the blade to rise and fall. The blade is selectively grounded or connected to an impedance circuit via a switch. Attached Figure Description

[0022] This disclosure will become more apparent from the accompanying drawings and detailed description. The embodiments described herein are provided by way of example rather than limitation, wherein like reference numerals refer to like or similar elements. The drawings are not necessarily drawn to scale, but are intended to illustrate aspects of this disclosure.

[0023] Figure 1 This is a perspective view of a substrate processing apparatus according to an exemplary embodiment of the present disclosure.

[0024] Figure 2 It is along Figure 1 A cross-sectional view of the substrate processing apparatus along the extracted line A-A'.

[0025] Figure 3 yes Figure 1 A conceptual diagram of the substrate processing device.

[0026] Figure 4 This is a conceptual diagram of a substrate processing apparatus according to another exemplary embodiment of the present disclosure. Detailed Implementation

[0027] A substrate processing apparatus according to an example embodiment may include a processing chamber, a substrate inlet formed on a sidewall of the processing chamber, and a valve for opening and closing the substrate inlet. The valve may include blades for opening and closing the substrate inlet, and a drive unit that allows the blades to move up and down. The blades may provide an inner side surface of the processing chamber between the lower surface of the processing chamber and the substrate inlet. That is, the blades may provide an inner side surface that forms part of the inner side surface of the chamber. Therefore, the inner side surface of the blades and the inner side surface of the processing chamber may be continuously connected to improve structural symmetry. Structural symmetry provides symmetry in gas flow and discharge to improve process uniformity.

[0028] During the process, contaminants may deposit on the inner side surface of the blades. As the blades rise and fall, contaminants may desorb from the blades, generating particles. When these particles adhere to the substrate in the processing chamber, they can cause component defects.

[0029] Furthermore, when plasma is generated in the processing chamber, the processing chamber can be maintained at a predetermined temperature and electrically grounded. The blades may not be electrically connected to the processing chamber and can contact the processing chamber using a sealing device such as an O-ring inserted between the blade and the processing chamber. Therefore, the blades can provide different electrical characteristics than the processing chamber to provide locally different plasma characteristics.

[0030] Therefore, it is necessary to suppress contaminant deposition on the blades and control their electrical characteristics. Contaminants on the blades can be removed by sputtering with incident plasma ions. A control electrode can be formed on the inner side surface of the blade, and DC or RF power can be applied to the control electrode. When a positive DC voltage is applied to the control electrode, positive ions in the plasma diffused in the reaction space are repelled to suppress contaminant deposition and alter the local plasma characteristics. When a negative DC voltage is applied to the control electrode, positive ions in the plasma diffused in the reaction space are attracted, causing contaminants to be sputtered to suppress deposition and alter the local plasma characteristics. When RF power is applied to the control electrode, additional plasma can be generated on its surface to sputter contaminants and alter the local plasma characteristics.

[0031] When the base is located at the center of the processing chamber, the RF-powered base and the grounded gas injector can face each other and form a main capacitor, while the base and the walls of the processing chamber can form parasitic capacitors. When the blade is placed on the side wall of the processing chamber, azimuth asymmetry of the parasitic capacitors can occur. That is, the variation in parasitic impedance between the base and the side wall of the grounded processing chamber can occur depending on the azimuth angle. This variation in parasitic impedance can affect the RF current flowing through the parasitic capacitor. To overcome the directional non-uniformity of plasma density caused by parasitic impedance, DC power or RF power can be applied to control electrodes intentionally positioned on the blade. For example, when the plasma density is locally low in the direction of the blade due to parasitic impedance, a negative DC voltage can be applied to the control electrode. When the negative voltage is so low as to a few volts, the control electrode charged with the negative DC voltage can attract or repel positive ions to control the local plasma density non-uniformity.

[0032] On the other hand, when the plasma density is locally high in the direction of the blade due to parasitic impedance, a positive voltage can be applied to the control electrode. The control electrode charged with a positive voltage can attract or repel positive ions to control the local plasma density inhomogeneity.

[0033] When RF power is applied to the control electrode, the control electrode can be operated as a new plasma source to control plasma density inhomogeneity.

[0034] According to an example embodiment, the blades may be grounded or connected to an impedance circuit. The impedance circuit may include LC circuits connected in parallel or in series. The capacitors in the impedance circuit impede direct current flow from the blades to ground. Additionally, the capacitors in the impedance circuit may carry RF current. The inductors in the impedance circuit may carry RF current having a phase opposite to that of the capacitors. Therefore, the impedance circuit can alter the impedance between the blades and ground to locally change plasma characteristics.

[0035] In the following description, embodiments of this disclosure will be described more fully with reference to the accompanying drawings. However, this disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0036] Figure 1 This is a perspective view of a substrate processing apparatus according to an exemplary embodiment of the present disclosure.

[0037] Figure 2 It is along Figure 1 A cross-sectional view of the substrate processing apparatus extracted along line A-A'.

[0038] Figure 3 yes Figure 1 A conceptual diagram of a substrate processing device.

[0039] Reference Figure 1-3 The substrate processing apparatus 100 may include a processing chamber 110, providing a reaction space 110a within the processing chamber, and including a substrate inlet 112 through which a substrate 152 enters or exits; a base 150 disposed inside the processing chamber 110 and supporting the substrate 152; a gas injector 160 disposed on an opposing surface of the base 150 to inject gas toward the substrate 152; a valve for opening and closing the substrate inlet 112; and a control electrode formed on the valve.

[0040] The substrate processing apparatus 100 can perform a deposition process or an etching process.

[0041] The processing chamber 110 may form a reaction space 110a, the reaction space 110a having a substrate inlet 112 on at least one sidewall of the processing chamber 110. The processing chamber 110 may have a cubic shape, and the reaction space 110a may have a cylindrical structure. The processing chamber 110 may have a lower surface 111b and sidewalls 111a.

[0042] A gas injector 160 may be disposed on the open upper surface of the processing chamber 110. The gas injector 160 is operable as a chamber cover. The gas injector 160 may be supplied with RF power to generate plasma. The processing chamber 110 may be emptied by a pump 169. The processing chamber 110 may be electrically grounded.

[0043] The substrate inlet 112 can penetrate the sidewall of the processing chamber 110 to connect to the reaction space 110a. The substrate inlet 112 can be continuously connected to the opening 113, in which blades 121 are disposed. The blades 121 can open and close the substrate inlet 112 while rising and falling. The substrate inlet 112 can provide structural symmetry for the processing chamber 110.

[0044] The gas injector 160 may include multiple nozzles and can inject gas supplied from the gas supply unit 164 into the reaction space 110a. The gas injector 160 may receive external RF power to generate plasma. A first RF power source 162 may supply RF power to the gas injector 160 via a first impedance matching network (not shown).

[0045] The base 150 may include a heating unit (not shown), on which the substrate 152 may be mounted and heated to a predetermined temperature. The base 150 may be vertically raised and lowered. The base 150 may include an electrostatic clamp (not shown) for securing the substrate 152. Additionally, the base 150 may receive external RF power to generate plasma and may adjust the energy incident on the substrate 152. A second RF power supply 166 may supply RF power to the base 150 via a second impedance matching circuit.

[0046] A valve 120 may be disposed on the inner side surface of the processing chamber 110 to open and close the substrate inlet 112. The valve 120 may suppress structural asymmetry of the processing chamber 110.

[0047] Valve 120 may include a blade 121 and an actuation unit 129, the blade 121 opening and closing the substrate inlet 112, and the actuation unit 129 allowing the blade to rise and fall. The actuation unit 129 may be connected to a sidewall or lower surface of the processing chamber 110 for support by a separate housing. The blade 121 may be inserted into an opening 113 formed in the sidewall of the processing chamber 110 to provide an internal side surface 122a, which forms part of the internal side surface of the processing chamber 110.

[0048] Blade 121 may be grounded or connected to impedance circuit 184. Impedance circuit 184 may include LC circuits connected in parallel or in series with each other.

[0049] When impedance circuit 184 includes a capacitor and an inductor, and the capacitor and inductor are connected in series, the impedance of impedance circuit 184 is at its minimum at the drive frequency, and impedance circuit 184 can constitute a resonant circuit. Impedance circuit 184 with minimum impedance can increase the RF current flowing through blade 121, and the blade can be stably grounded to stabilize the plasma. That is, blade 121 can be controlled by impedance circuit 184 to have the same electrical characteristics as the inner wall of processing chamber 110. Impedance circuit 184 can be an LC series resonant circuit, such that blade 121 provides the same electrical characteristics as the inner wall of the processing chamber in an uncontaminated state.

[0050] On the other hand, when the impedance circuit 184 includes a capacitor and an inductor, and the capacitor and inductor are connected in parallel with each other, the impedance of the impedance circuit 184 is at its maximum value at the driving frequency, and the impedance circuit 184 can constitute a resonant circuit. Therefore, the impedance circuit 184 can increase the impedance between the blade 121 and the ground to reduce the RF current flowing through the blade 121, allowing a large amount of RF current to flow through the wall of the processing chamber 110. Therefore, the plasma characteristics can be locally altered. The impedance circuit 184 can be an LC parallel resonant circuit, such that the blade 121 provides the same electrical characteristics as in a state where the inner wall of the processing chamber is heavily contaminated.

[0051] The first switch 182 can be selectively connected to ground and the first impedance circuit 184. The capacitor of the first impedance circuit 184 is variable and can regulate the RF current flowing from the blade 121 to ground. The impedance circuit 184 can change the impedance between ground and blade 121 to alter local plasma characteristics.

[0052] Blade 121 may not be electrically connected to processing chamber 110 and may contact processing chamber 110 using a sealing device such as an O-ring inserted between blade 121 and processing chamber 110. Therefore, blade 121 can provide different electrical characteristics than processing chamber 110 to provide locally different plasma characteristics. Blade 121 may be grounded or connected to ground via a first impedance circuit 184 to control plasma characteristics via blade 121.

[0053] A control electrode 130 may be formed on the inner side surface 122a of the blade 121. The control electrode 130 may be arranged via the blade 121 and the insulating layer 132 for insulation. The control electrode 130 may be formed in the azimuth direction of the inner side surface 122a to have an arcuate strip shape. The control electrode 130 may be positioned adjacent to the upper surface of the opening 113 to interact with the plasma in the reaction space. The area of ​​the control electrode 130 may be a fraction of a second or less smaller than the area of ​​the wall of the processing chamber 110. In this case, the voltage applied to the control electrode may alter the local plasma density distribution and have little effect on the plasma potential.

[0054] DC power supply 174, ground, or RF power supply 176 can be selectively connected to control electrode 130 via second switch 172. DC power supply 174 can be a positive DC power supply or a negative DC power supply.

[0055] During the process, contaminants can deposit on the inner side surface of blade 121. As blade 121 rises and falls, the contaminants can be desorbed, resulting in particle generation. When these particles adhere to the substrate in the processing chamber, they can cause component defects.

[0056] Therefore, it is necessary to suppress the deposition of pollutants on the blade 121 and control the electrical characteristics through the blade.

[0057] DC or RF power can be applied to the control electrode 130. When a positive DC voltage is applied to the control electrode 130, positive ions in the plasma diffused in the reaction space 110a are repelled to suppress contaminant deposition or alter local plasma characteristics. When a negative DC voltage is applied to the control electrode 130, positive ions in the plasma diffused in the reaction space 110a are attracted, causing contaminants to be sputtered to suppress contaminant deposition or alter local plasma characteristics. When RF power is applied to the control electrode 130, individual plasmas can be generated on the surface of the control electrode 130 to sputter contaminants or alter local plasma characteristics. Therefore, the azimuth symmetry of the plasma can be improved, and the substrate processing uniformity can be increased.

[0058] Figure 4 This is a conceptual diagram of a substrate processing apparatus according to another exemplary embodiment of the present disclosure.

[0059] Reference Figure 4The substrate processing apparatus 100a may include a processing chamber 110 providing a reaction space 110a within the processing chamber; a base 150 disposed inside the processing chamber 110 and supporting a substrate 152; a gas injector 160 disposed on an opposing surface of the base 150 to inject gas toward the substrate 152; and a control electrode 230 partially formed on the exterior of the base 150 or on an interior side surface, the interior side surface forming part of the interior side surface of the processing chamber 110.

[0060] The control electrode 230 may be formed on a separate control electrode support unit 232, rather than on the inner side surface 122a of the blade 121, and may be partially disposed outside the base 150. The control electrode 230 may have, for example... Figure 1 The same shape. The control electrode 230 may be partially disposed to make the blade 121 visible. The control electrode support unit 232 may be configured to rotate in an azimuth direction relative to the rotating device (not shown) so that the substrate 152 enters or leaves, and the control electrode support unit 232 may then be rotated again to perform the alignment process to make the blade 121 visible.

[0061] As described above, the substrate processing apparatus according to the example embodiment can use control electrodes to provide a uniform process environment to the entire reaction space of the chamber and suppress particle generation.

[0062] Additionally, a valve with an internally curved surface (forming part of the inner side surface of the chamber) can be inserted and connected to an impedance circuit to alter the electrical characteristics. Therefore, the substrate processing apparatus can control localized process inhomogeneities on the substrate.

[0063] Although the present disclosure and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A substrate processing apparatus, comprising: A processing chamber provides a reaction space within the processing chamber and includes a substrate inlet through which the substrate enters or exits; A base is disposed inside the processing chamber and supports the substrate; A gas injector is disposed on the opposite surface of the base to inject gas into the substrate; The valve opens and closes the substrate inlet; as well as Control electrodes formed on the valve, The valve includes blades that open and close the substrate inlet and has an inner surface that forms part of the inner side surface of the processing chamber. The gas injector is supplied with RF power to generate plasma. The control electrode is used to control localized process non-uniformity. The voltage applied to the control electrode alters the local plasma density distribution.

2. The substrate processing apparatus of claim 1, wherein the control electrode is vertically driven.

3. The substrate processing apparatus of claim 1, wherein the valve further comprises The drive unit allows the blades to rise and fall, and The control electrode is formed on the blade.

4. The substrate processing apparatus of claim 3, wherein the blade is selectively grounded or connected to an impedance circuit via a first switch.

5. The substrate processing apparatus of claim 4, wherein the impedance circuit comprises LC circuits connected in parallel or in series with each other, and The capacitors that make up an LC circuit are variable.

6. The substrate processing apparatus of claim 1, wherein the control electrode is connected to the power supply unit.

7. The substrate processing apparatus of claim 6, wherein the power supply unit includes at least one of a positive DC power supply, a negative DC power supply, and an RF power supply.

8. The substrate processing apparatus of claim 7, further comprising: The second switch is configured to connect to the power supply unit or ground and to the control electrode. The second switch is selectively connected to at least one of the positive DC power supply, the negative DC power supply, and the RF power supply.

9. A substrate processing apparatus, comprising: A processing chamber that provides a reaction space within the processing chamber; A base is disposed inside the processing chamber and supports the substrate; A gas injector is disposed on the opposite surface of the base to inject gas toward the substrate; as well as A valve, having an internal side surface that forms part of the internal side surface of the processing chamber, opens and closes the substrate inlet of the processing chamber. The valve mentioned above includes: The blade opens and closes the substrate inlet and has the inner side surface that forms part of the inner side surface of the processing chamber; as well as The drive unit allows the blades to rise and fall, and The blades are selectively grounded or connected to an impedance circuit via a switch. The base is supplied with RF power to generate plasma. Use control electrodes to control localized process non-uniformity. The voltage applied to the control electrode alters the local plasma density distribution.

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