Substrate Processing Equipment and Substrate Processing Method

Abstract

Examples of substrate processing equipment include: a platen; a drive unit for rotating the platen; an electrode that faces only a part of the outer edge of the platen; a high-frequency power supply unit for supplying high-frequency power to the electrode; and a gas supply device for supplying gas to the gap between the electrode and the platen.

Description

Technical Field

[0001] Examples related to a substrate processing apparatus and a substrate processing method using the substrate processing apparatus are described. Background Art

[0002] In a semiconductor or liquid crystal manufacturing process, the outer peripheral portion or the back surface of a substrate makes mechanical contact with the hand of a transfer robot. When the hand of the transfer robot, for example, contacts a thin film disposed on the side surface portion of the substrate, the thin film peels off, resulting in the generation of particles. These minute particles cause electrical failures in highly integrated devices and lead to a serious reduction in production. In addition, a conductive film formed so as to spread around the outer peripheral portion of the back surface of the substrate interferes with the electrostatic attraction of the substrate or generates a direct current passing vertically through the substrate, thereby causing damage to elements in subsequent processes.

[0003] Selective removal of a film on the outer periphery of a substrate is considered a method for preventing the generation of particles due to mechanical contact with the outer peripheral portion of the substrate. For example, a reactive gas is caused to flow to the outer peripheral portion of the substrate, and high-frequency power is applied to an electrode disposed above the outer peripheral portion to generate plasma around the outer peripheral portion. In this method, a very small interval is set between the electrodes, thereby preventing the diffusion of the gas directed to the center of the substrate and the entrapment of the plasma. The ignition voltage of the plasma is represented by a function of the product p*d of the internal pressure p of the reactor and the electrode interval d according to Paschen's law. Since the ignition voltage of the plasma is proportional to 1 / d, the ignition voltage increases when d is very small, making it difficult to obtain uniform and stable plasma. Therefore, film formation and film removal at the outer peripheral portion of the substrate are non-uniform, which adversely affects the yield. Summary of the Invention

[0004] Some examples described herein can solve the above problems. Some examples described herein can provide a substrate processing apparatus and a substrate processing method that can perform stable plasma processing on the edge of a substrate or on a portion near the edge.

[0005] In some examples, a substrate processing apparatus includes: a stage; a driving unit for rotating the stage; an electrode facing only a part of the outer edge of the stage; a high-frequency power supply unit for supplying high-frequency power to the electrode; and a gas supply device for supplying gas to a gap between the electrode and the stage. Brief Description of the Drawings

[0006] Figure 1 is a schematic diagram showing a configuration example of a substrate processing apparatus;

[0007] Figure 2 is a plan view of the stage and the electrode;

[0008] Figure 3A graph showing the influence of the shape of the electrode on the processing result;

[0009] Figure 4 A schematic diagram showing a structural example of a substrate processing apparatus according to another example;

[0010] Figure 5 A schematic diagram showing a structural example of a substrate processing apparatus according to another example;

[0011] Figure 6 A schematic diagram showing a structural example of a substrate processing apparatus according to another example. Detailed Description of the Invention

[0012] A substrate processing apparatus and a substrate processing method according to some examples will be described with reference to the accompanying drawings. The same or corresponding components are denoted by the same reference numerals, and their repeated description may be omitted.

[0013] Figure 1 A schematic diagram showing a structural example of a substrate processing apparatus 2. The substrate processing apparatus includes a stage 10 accommodated in a chamber 11. The stage 10 can be an electrode, such as an electrostatic chuck electrode (ESC electrode). The stage 10 can be a temperature-adjustable pedestal. The stage 10 can be rotated by a driving unit 12. The driving unit 12 rotates the stage 10 with the y-axis as the rotation axis. In an example, the driving unit 12 can be an electric motor. The stage 10 can be rotated by various methods.

[0014] A substrate 14 to be processed as a target is placed on the stage 10. The diameter of the substrate 14 is larger than the diameter of the stage 10. For example, the diameter of the substrate 14 can be 300 mm and larger than the stage 10. Therefore, the edge of the substrate and its outer peripheral portion 14a extending from the edge are not supported by the stage 10. The substrate 14 can be a material for manufacturing a semiconductor device or liquid crystal.

[0015] The substrate processing apparatus 2 can include an electrode 16 provided beside the stage 10. The shape of the electrode 16 can be arc-shaped. The substrate processing apparatus 2 can also include an AC power supply 18 that supplies high-frequency power to the electrode 16 and can be connected to the electrode 16.

[0016] Figure 2 Is Figure 1 A plan view of a part of the substrate processing apparatus 2, showing at least the stage 10, the substrate 14, and the electrode 16. The outer edge of the stage 10 is indicated by a dashed line. The electrode 16 only faces a part of the outer edge of the stage 10. In other words, the electrode 16 does not surround the stage 10. The distance between the electrode 16 and the stage 10 can be equal to or greater than 10 mm. In some examples, the electrode 16 faces 1 / 20 or less of the outer edge of the stage 10.

[0017] For example, Figure 2 It is shown that the substrate processing apparatus 2 can also include a system 17, an AC power supply 18 (e.g., a radio frequency generator), and a matching circuit 19 is arranged to apply high-frequency power to the electrode 16. The AC power supply 18 can receive instructions from the system 17 to supply high-frequency power to the electrode 16 via the matching circuit 19. It is noted that the system 17, the AC power supply 18, and the matching circuit 19 are an example of a high-frequency power supply unit for supplying high-frequency power to the electrode 16, and the substrate processing apparatus 2 can include any other suitable high-frequency power supply unit to replace or combine at least one of the system 17, the AC power supply 18, and the matching circuit 19.

[0018] Review Figure 1 , the substrate processing apparatus 10 can include a mask block 20 to prevent the removal of material from a part of the substrate 14 during operation. The mask block 20 is arranged above the platen 10 so as to be separated from the platen 10. The material of the mask block 20 can be an insulator (e.g., a ceramic material) or any other suitable material. The distance between the mask block 20 and the platen 10 is greater than the thickness of the substrate 14. In an example, the distance between the mask block 20 and the platen 10 can be at least 1 mm, 1 to 3 mm, or 1 to 5 mm. The mask block 20 can define a through hole 20a extending vertically therethrough. The through hole 20a is supplied with purge gas from a purge gas supply device 22 via a pipe connecting the purge gas supply device 22 to the through hole 20a. As a result, the purge gas is supplied into a space 20b formed between at least two of the platen 10, the substrate 14, or the mask block 20 and defined by at least two of the platen 10, the substrate 14, or the mask block 20 via the through hole 20a. The purge gas can flow radially with respect to the platen 10 through the space 20b. The purge gas supplied by the purge gas supply device 22 can be argon, nitrogen, or helium.

[0019] The substrate processing apparatus 2 can include a gas supply device 24 to supply gas, for example, via a pipe, into a gap 23 formed between the electrode 16 and the platen 10 and formed by the electrode 16 and the platen 10. The gas supply device 24 can supply an etching gas (e.g., oxygen, nitrogen trifluoride, helium, or argon) or a material gas for film formation to the gap 23.

[0020] The gas flow rate of the gas from the gas supply device 24 and the purge gas from the purge gas supply device 22 can be controlled by a mass flow controller (not shown), the system 17, the controller 26, or any other suitable controller. The mass flow controller can be communicatively coupled to the gas supply device 24 or the purge gas supply device 22 and at least partially control the operation of the gas supply device 24 or the purge gas supply device 22.

[0021] The substrate processing apparatus 2 can include an exhaust pipe 25 that can exhaust the purified gas supplied from the purified gas supply device 22 and the gas supplied from the gas supply device 24. The substrate processing apparatus 2 can also include a control valve 27 and an exhaust pump 28 that are at least partially controlled by a controller 26, thereby optimizing the pressure in the chamber 11. For example, the control valve 27 and the exhaust pump 28 are controlled such that the gas supplied from the gas supply device 24 mainly fills the chamber 11. The exhaust pipe 25, the control valve 27, and the exhaust pump 28 can together form an exhaust passage.

[0022] The substrate processing apparatus 2 can include an impedance adjustment electrode 30 disposed to face the electrode 16. The impedance adjustment electrode 30 is grounded via a variable capacitor 32. The impedance adjustment electrode 30 can be disposed above or below the platen 10. The impedance adjustment electrode 30 provides a ground wire that is different from the platen 10, is close to the electrode 16, and serves as a discharge plug. A high-frequency impedance that can be modified (e.g., optimized) to improve discharge stability can be created by adjusting the capacitance of the variable capacitor 32.

[0023] The substrate processing apparatus 2 can include a measuring device 34 disposed above the platen 10. The measuring device 34 can be at least one of a camera, a thermometer, or a film thickness measuring device. The measuring device 34 is disposed to observe the outer peripheral portion 14a of the substrate 14 from above. The outer peripheral portion of the substrate 14 is an annular portion that extends along the edge in the substrate 14. For example, the completion of film removal or the completion of film formation at the outer peripheral portion 14a is monitored in real time by the measuring device 34.

[0024] Use Figure 1 and Figure 2 An example of a substrate processing method of the substrate processing apparatus 2 can include placing a substrate 14 having a diameter larger than that of the platen 10 on the platen 10. As a result, as Figure 1 and Figure 2 shown, the outer peripheral portion 14a of the substrate 14 protrudes from the outer edge of the platen 10. For example, the substrate 14 is in close contact with the platen 10 by an electrostatic chuck of the platen 10 that can accurately position the substrate 14 on the platen 10, and the discharge from the electrode 16 is stabilized.

[0025] Next, while the substrate processing apparatus 2 generates a plasma 16a between the electrode 16 and the platen 10, the platen 10 is rotated. For example, high-frequency power is supplied from the AC power supply 18 to the electrode 16, and a gas is supplied from the gas supply device 24 to the gap 23 between the electrode 16 and the platen 10 to generate a plasma. The electrode 16 and the platen 10 can form two capacitively coupled electrodes, thereby generating a capacitively coupled plasma. The electrode 16 can be used as a compact discharge plug. The diameter of the platen 10 is set to be smaller than the outer diameter of the substrate 14, thereby exposing the outer peripheral portion 14a of the back surface of the substrate 14 to the plasma.

[0026] A stable plasma is generated by adjusting the discharge conditions of the electrode 16. For example, the impedance can be locally changed by the impedance adjusting electrode 30 and the varactor 32 to promote the generation of the plasma and stabilize the plasma. For example, the varactor 32 can be adjusted to achieve an optimized impedance.

[0027] During the execution of the plasma processing, a purge gas is supplied from the purge gas supply device 22 to the through hole 20a of the mask module 20 so that the purge gas flows radially through the space 20b between at least two of the platen 10, the substrate 14, or the mask module 20. As a result, it is possible to substantially prevent the gas supplied from the gas supply device 24 from reaching the upper surface of the substrate 14. By the mask module 20 and the purge gas provided by the purge gas supply device 22, significant plasma processing can be substantially reduced and / or avoided on the upper surface of the substrate 14.

[0028] While the substrate 14 is rotated as indicated by the arrow in Figure 2 , the outer peripheral portion 14a of the substrate 14 is successively subjected to plasma processing. The plasma processing can either remove the film formed on the side and back surfaces of the substrate 14 or form a film on the side and back surfaces of the substrate 14. By subjecting the outer peripheral portion 14a of the substrate 14 to plasma processing with a stable plasma, uniform film formation (and / or film formation with improved uniformity) or uniform film removal (and / or film removal with improved uniformity) can be performed in some examples.

[0029] In addition, the state of the outer peripheral portion 14a of the substrate 14 can be monitored by the measuring device 34. For example, in real time, it can be checked whether the film at the outer peripheral portion 14a has been removed, or it can be checked whether film formation has been performed at the outer peripheral portion 14a. To enable such monitoring, the mask module 20 can be provided at a position other than directly above the outer peripheral portion 14a.

[0030] Figure 3 The influence of the shape of the electrode on the processing result is shown. In Figure 3In the example, the outer diameter of the platen serving as the ground-side electrode is set to 295 mm. A substrate having a diameter of 300 mm and formed of silicon is placed on the platen. The substrate includes a film of amorphous carbon formed thereon. In this example, the film at the outer peripheral portion of the substrate 14 is removed by oxygen plasma for 10 minutes.

[0031] In an embodiment, the electrode of the substrate processing apparatus includes a discharge plug formed of aluminum and having a width of 40 mm. High-frequency power is applied to the discharge plug to cause discharge while the platen is rotating, whereby the entire outer peripheral portion of the substrate is subjected to plasma processing. The film thickness profile detected after using the discharge plug is indicated by the solid line shown in Figure 3 In an embodiment, the electrode of the substrate processing apparatus includes an annular electrode formed of aluminum that surrounds the platen and faces the entire outer edge of the platen. High-frequency power is applied to the annular electrode to cause discharge while the platen is rotating / stationary, whereby the entire outer peripheral portion of the substrate is subjected to plasma processing. The film thickness detected after using the annular electrode is indicated by the dashed line shown in Figure 3 The dashed line shown in

[0032] The data of both the solid line and the dashed line in Figure 3 are measured at an inner position 2 mm from the outer edge of the substrate. In both cases, the distance between the electrode (e.g., the discharge plug or the annular electrode) and the platen 10 is set to 12 mm, and the frequency of the high-frequency power applied to the electrode is set to 13.56 MHz.

[0033] From Figure 3 the comparison between the solid line and the dashed line, it is apparent that, compared to the case of using an annular electrode that surrounds the platen, by providing a discharge plug that faces only a part of the outer edge of the platen, the in-plane uniformity of the film thickness is enhanced. Thus, in some examples, referring to Figure 1 and Figure 2 the electrode 16 should face only a part of the outer edge of the platen 10 and not surround the platen 10. When using an annular electrode that surrounds the platen 10 as the electrode 16, it may be difficult to obtain a uniform gas flow and plasma in the entire portion where the electrode 16 and the platen 10 face each other, and the thickness of the carbon film varies greatly depending on the position. On the other hand, in some embodiments, an annular electrode can be used as the electrode 16 to cause stable discharge in a limited area, and thus perform film removal with improved uniformity, such as when the electrode 16 is made compact and faces only a part of the outer edge of the platen 10.

[0034] Figure 4 FIG. is a schematic diagram showing a configuration example of a substrate processing apparatus 2′ according to another example. Unless otherwise disclosed herein, the substrate processing apparatus 2′ can be the same as or substantially similar to any substrate processing apparatus described herein. Referring toFigure 4 , the platen 10 is grounded via the variable capacitor 50. By adjusting the capacitance of the variable capacitor 50, the impedance can be adjusted (e.g., optimized) when plasma is generated.

[0035] Figure 5 FIG. is a schematic diagram showing a configuration example of a substrate processing apparatus 2″ according to another example. Unless otherwise disclosed herein, the substrate processing apparatus 2″ can be the same as or substantially similar to any substrate processing apparatus described herein. Refer to Figure 5 , gas is supplied from the lower side of the platen 10 by the gas supply device 52 into the gap 23 between the electrode 16 and the platen 10. As a result, sufficient gas can be supplied from the gas supply device 52 to the back side of the substrate 14, so that in particular, the desired plasma processing can be performed on the back side of the substrate 14.

[0036] Figure 6 FIG. is a schematic diagram showing a configuration example of a substrate processing apparatus 2″′ according to another example. Unless otherwise disclosed herein, the substrate processing apparatus 2″′ can be the same as or substantially similar to any substrate processing apparatus described herein. Refer to Figure 6 , the electrode 16A is provided at the same level as the upper ends of one or more of the substrate 14 and the platen 10, or only below the upper end. As a result, plasma mainly appears beside the side surface of the substrate 14 and below the back surface of the substrate 14. In this case, while plasma processing on the upper surface of the substrate 14 can be sufficiently suppressed, plasma processing can be performed on the side surface and the back surface of the substrate 14. The shape of the electrode can be changed, or the distance between the electrode and the platen 10 can be adjusted by other methods.

Claims

1. A substrate processing apparatus, comprising: A platen, the platen being grounded; A drive unit for rotating the platen; An electrode that faces only a part of the outer edge of the platen and does not surround the platen; A high-frequency power supply unit for supplying high-frequency power to the electrode; A gas supply device for supplying gas to the gap between the electrode and the platen to generate plasma in the gap between the electrode and the platen; An impedance adjustment electrode arranged to face the electrode; and A capacitor for grounding the impedance adjustment electrode.

2. The substrate processing apparatus according to claim 1, further comprising: A mask module arranged above the platen so as to be separated from the platen; And A purge gas supply device for supplying purge gas to the space between the platen and the mask module to generate an air flow traveling radially with respect to the platen.

3. The substrate processing apparatus according to claim 1 or 2, wherein, The shape of the electrode is arc-shaped.

4. The substrate processing apparatus according to claim 1 or 2, further comprising an impedance adjustment electrode that faces the electrode and is grounded via a capacitor.

5. The substrate processing apparatus according to claim 4, wherein, The impedance adjustment electrode is arranged above the platen.

6. The substrate processing apparatus according to claim 1 or 2, further comprising a measuring device arranged above the platen.

7. The substrate processing apparatus according to claim 6, wherein, The measuring device is a camera, a thermometer, or a film thickness measuring device.

8. A substrate processing method, comprising: Placing a substrate having a diameter larger than that of the platen on the platen, the platen being grounded; Rotating the platen while generating plasma in the gap between the electrode that faces only a part of the outer edge of the platen and the platen by applying high-frequency power to the electrode and supplying gas to the gap between the electrode and the platen; And Stabilizing the generation of plasma by adjusting the discharge conditions of the electrode through an impedance adjustment electrode arranged to face the electrode and a capacitor arranged to ground the impedance adjustment electrode.

9. The substrate processing method according to claim 8, wherein, The plasma removes the film formed on the side and back surfaces of the substrate.

10. The substrate processing method according to claim 8, wherein, The plasma forms a film on the side and back surfaces of the substrate.

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