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KR-102962253-B1 - PLASMA PROCESSING APPARATUS AND PROCESSING METHOD

KR102962253B1KR 102962253 B1KR102962253 B1KR 102962253B1KR-102962253-B1

Abstract

[Project] Reduce the energy of ions incident on the lower electrode without increasing the energy of ions incident on the upper electrode. [Solution] A processing vessel, a lower electrode provided inside the processing vessel, an upper electrode positioned opposite to the lower electrode, a gas supply unit configured to supply processing gas between the upper electrode and the lower electrode, a high-frequency power source configured to generate plasma of the processing gas by applying a high-frequency voltage to the upper electrode, and a voltage waveform shaping unit provided between the high-frequency power source and the upper electrode and configured to shape the voltage waveform of the high-frequency voltage output from the high-frequency power source by converting a positive voltage component into a negative voltage component.

Inventors

  • 오토모 히로시
  • 신도 다카히로

Assignees

  • 도쿄엘렉트론가부시키가이샤

Dates

Publication Date
20260507
Application Date
20220705
Priority Date
20210716

Claims (12)

  1. Processing container and, A lower electrode provided inside the above-mentioned processing vessel, and An upper electrode positioned opposite to the lower electrode, and A gas supply unit configured to supply a processing gas between the upper electrode and the lower electrode, and A high-frequency power supply configured to output a high-frequency voltage, and A voltage waveform shaping unit provided between the high-frequency power source and the upper electrode, configured to shape the voltage waveform of the high-frequency voltage output from the high-frequency power source by converting a positive voltage component into a negative voltage component. Equipped with, A high-frequency voltage having a voltage waveform in which the positive voltage component of the high-frequency voltage output from the high-frequency power source is converted into the negative voltage component by the voltage waveform shaping unit is applied to the upper electrode, and The lower electrode above is a substrate mounting base on which a substrate is mounted, and is an electrically grounded conductor. Plasma processing device.
  2. In Article 1, Further equipped with a shower head for introducing the above-mentioned processing gas into the interior of the processing vessel, The above shower head is the upper electrode Plasma processing device.
  3. In Article 1 or Article 2, A plasma processing device further comprising a matching unit electrically connected between the high-frequency power source and the voltage waveform shaping unit.
  4. In Article 1 or Article 2, The above-mentioned processing gas comprises a gas used for forming a film and providing the raw material of the film to a substrate disposed within the processing vessel. Plasma processing device.
  5. In Article 1 or Article 2, The above voltage waveform shaping unit has a transformer, a first rectifier, and a second rectifier, and The above transformer has a primary coil and a secondary coil, and Between the two terminals of the primary coil, the high-frequency power source is electrically connected, and The above secondary coil has two coils connected in series, Each of the two terminals of the secondary coil is electrically connected to the cathode of the first rectifier and the cathode of the second rectifier, respectively, and The connection point of the two coils of the secondary coil is electrically grounded, and The anode of the first rectifier and the anode of the second rectifier are electrically connected to the upper electrode. Plasma processing device.
  6. In Article 1 or Article 2, The above voltage waveform shaping unit has a transformer and a diode bridge circuit, and The above transformer has a primary coil and a secondary coil, and The high-frequency power source is electrically connected between the two terminals of the primary coil, and The above diode bridge circuit has a first rectifier, a second rectifier, a third rectifier, and a fourth rectifier, The cathode of the first rectifier is electrically connected to the anode of the second rectifier, and The anode of the first rectifier is electrically connected to the anode of the third rectifier, and The cathode of the second rectifier is electrically connected to the cathode of the fourth rectifier, and The cathode of the third rectifier is electrically connected to the anode of the fourth rectifier, and The cathode of the first rectifier is electrically connected to the cathode of the third rectifier through the secondary coil, and The anode of the first rectifier and the anode of the third rectifier are electrically connected to the upper electrode, and The cathode of the second rectifier and the cathode of the fourth rectifier are electrically grounded. Plasma processing device.
  7. In Article 1 or Article 2, The above voltage waveform shaping unit has a diode bridge circuit, The above diode bridge circuit has a first rectifier, a second rectifier, a third rectifier, and a fourth rectifier, The cathode of the first rectifier is electrically connected to the anode of the second rectifier, and The anode of the first rectifier is electrically connected to the anode of the third rectifier, and The cathode of the second rectifier is electrically connected to the cathode of the fourth rectifier, and The cathode of the third rectifier is electrically connected to the anode of the fourth rectifier, and Each of the two terminals of the above high-frequency power supply is electrically connected to the cathode of the first rectifier and the cathode of the third rectifier, respectively, and The anode of the first rectifier and the anode of the third rectifier are electrically connected to the upper electrode, and The cathode of the second rectifier and the cathode of the fourth rectifier are electrically connected to the lower electrode. Plasma processing device.
  8. In Article 1 or Article 2, The above voltage waveform shaping unit has a transformer, a first switching element, and a second switching element, and The above transformer has a primary coil and a secondary coil, and Between the two terminals of the primary coil, the high-frequency power source is electrically connected, and The above secondary coil has two coils connected in series, Each of the two terminals of the secondary coil is electrically connected to each of the first switching element and the second switching element, and The connection point of the two coils of the secondary coil is electrically grounded, and Each of the two terminals of the secondary coil is electrically connected to the upper electrode through each of the first switching element and the second switching element, and The first switching element and the second switching element are configured to block the current flowing from the secondary coil. Plasma processing device.
  9. A processing method for performing plasma treatment on a substrate placed inside a processing vessel of a plasma processing device, A process of supplying a processing gas between the upper electrode and the lower electrode of the above plasma processing device, and A process for shaping the voltage waveform of a high-frequency voltage output from a high-frequency power source of a plasma processing device by converting a positive voltage component into a negative voltage component, and The method comprises a process of applying the above high-frequency voltage to the upper electrode after shaping, In the process of applying to the upper electrode, a high-frequency voltage having a voltage waveform in which the positive voltage component of the high-frequency voltage output from the high-frequency power source is converted into the negative voltage component is applied to the upper electrode, and The lower electrode above is a substrate mounting base on which a substrate is mounted, and is an electrically grounded conductor, and A processing method comprising a gas that is used to form a film and provides the raw material for the film to the substrate.
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Description

Plasma Processing Apparatus and Processing Method An exemplary embodiment of the present disclosure relates to a plasma treatment apparatus and a treatment method. Plasma processing is widely used as a processing method for substrates such as semiconductor wafers. Patent document 1 discloses a technology for generating a bias output wave that reduces the positive voltage component of a high-frequency voltage waveform of the fundamental frequency, thereby reducing the energy of ions irradiated onto the chamber body of a plasma processing device. FIG. 1 is a schematic drawing showing a plasma processing apparatus according to one exemplary embodiment. Figure 2 is a diagram showing the configuration of a voltage waveform shaping section according to an example. Figure 3 is a diagram illustrating the shape of the voltage applied to the upper electrode. Figure 4 is a diagram illustrating the shape of the voltage applied to the upper electrode. Figure 5 is a diagram illustrating the shape of the voltage applied to the upper electrode. Figure 6 is a diagram showing the configuration of a voltage waveform shaping section according to another example. Figure 7 is a diagram showing the configuration of a voltage waveform shaping section according to another example. Figure 8 is a diagram showing the configuration of a voltage waveform shaping section according to another example. Figure 9 is a diagram showing the configuration of a lower electrode according to another example. FIG. 10 is a flowchart illustrating a processing method according to one exemplary embodiment. Various exemplary embodiments are described below. In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus comprises a processing vessel, a lower electrode, an upper electrode, a gas supply unit, a high-frequency power source, and a voltage waveform shaping unit. The lower electrode is provided inside the processing vessel. The upper electrode is positioned opposite to the lower electrode. The gas supply unit is configured to supply processing gas between the upper electrode and the lower electrode. The high-frequency power source is configured to generate plasma of the processing gas by applying a high-frequency voltage to the upper electrode. The voltage waveform shaping unit is provided between the high-frequency power source and the upper electrode and is configured to shape the voltage waveform of the high-frequency voltage output from the high-frequency power source by converting a positive voltage component into a negative voltage component. Since the voltage waveform is shaped by full-wave rectification that converts a positive voltage component into a negative voltage component, the peak of the negative voltage component of the shaped voltage applied to the upper electrode becomes equal to the peak of the negative voltage component of the voltage that was not shaped (for example, a sinusoidal voltage output by a high-frequency power source). Because of this, the increase in the sheath voltage on the upper electrode can be suppressed while simultaneously reducing the sheath voltage on the lower electrode. Consequently, the suppression of the increase in the energy of ions impacting the upper electrode and the reduction of the energy of ions incident toward the lower electrode are realized. In one exemplary embodiment, the plasma treatment apparatus further comprises a shower head. The shower head introduces a treatment gas into the interior of a treatment vessel. The shower head is an upper electrode. In one exemplary embodiment, the plasma processing apparatus further comprises a matching unit. The matching unit is electrically connected between a high-frequency power source and a voltage waveform shaping unit. In one exemplary embodiment, the processing gas comprises a gas used for forming a film and providing the film material to a substrate disposed within a processing vessel. In one exemplary embodiment, the voltage waveform shaping unit comprises a transformer, a first rectifier, and a second rectifier. The transformer has a primary coil and a secondary coil. A high-frequency power source is electrically connected between two terminals of the primary coil. The secondary coil has two coils connected in series. Each of the two terminals of the secondary coil is electrically connected to the cathode of the first rectifier and the cathode of the second rectifier, respectively. The connection point of the two coils of the secondary coil is electrically grounded. The anode of the first rectifier and the anode of the second rectifier are electrically connected to an upper electrode. In one exemplary embodiment, the voltage waveform shaping unit has a transformer and a diode bridge circuit. The transformer has a primary coil and a secondary coil. A high-frequency power source is electrically connected between two terminals of the primary coil. The diode bridge circuit has a first rectifier, a secon