CN-122029634-A - Radio Frequency (RF) matching network and tuning technique

Abstract

Embodiments provided herein generally include apparatus, plasma processing systems, and tuning methods for improving substrate processing metrics in a Radio Frequency (RF) plasma processing system. Some embodiments are directed to a method for processing a substrate in a plasma processing system. The method generally includes sensing, by one or more sensors, one or more intermodulation or harmonic components of a signal at a node coupled to a plasma chamber, and controlling one or more signal processing devices of the plasma processing system to process the substrate based on the one or more intermodulation or harmonic components and according to a frequency domain configuration identified by analyzing one or more substrate processing metrics.

Inventors

• GUO YUE
• K. RAMASWAMI
• A. N.M.W. Azad
• N J Brett
• YANG YANG

Assignees

• 应用材料公司

Dates

Publication Date

20260512

Application Date

20240809

Priority Date

20230908

Claims (20)

1. 1. A method for processing a substrate in a plasma processing system, the method comprising: Sensing one or more intermodulation or harmonic components of a signal at a node coupled to the plasma chamber by one or more sensors, and One or more signal processing devices of the plasma processing system are controlled to process the substrate based on the one or more intermodulation or harmonic components and according to a frequency domain configuration identified by analyzing one or more substrate processing metrics.
2. 2. The method of claim 1, further comprising sensing frequency components of another substrate to identify the frequency domain configuration to conform to the one or more substrate processing metrics, wherein the one or more intermodulation or harmonic components correspond to the frequency components.
3. 3. The method of claim 1, wherein the frequency domain configuration includes a ratio between magnitudes of at least two intermodulation or harmonic components.
4. 4. The method of claim 1, wherein the one or more substrate processing metrics comprise process variation, etch rate, or uniformity associated with substrate processing.
5. 5. The method of claim 1, further comprising constructing a Pulse Voltage (PV) waveform based on the sensed one or more intermodulation or harmonic components, wherein the one or more signal processing devices are controlled based on the constructed PV waveform.
6. 6. The method of claim 5, wherein the one or more signal processing devices include at least one of a PV waveform generator or a Radio Frequency (RF) generator controlled based on the constructed PV waveform.
7. 7. The method of claim 1, wherein the one or more signal processing devices comprise a matching circuit, and wherein the node coupled to the plasma chamber comprises an output of the matching circuit.
8. 8. The method of claim 7, wherein the node coupled to the plasma chamber is external to the matching circuit.
9. 9. The method of claim 1, wherein controlling the one or more signal processing devices includes controlling at least one of a magnitude or a phase of one or more output signals of the one or more signal processing devices.
10. 10. The method of claim 1, wherein the one or more signal processing devices comprise: first matching circuit A second matching circuit, wherein the one or more sensors include a sensor coupled to outputs of the first matching circuit and the second matching circuit.
11. 11. The method of claim 10, wherein the one or more signal processing devices comprise: A first generator having an output coupled to the first matching circuit, and A second generator having an output coupled to the second matching circuit, wherein the sensor is configured to provide a feedback signal to at least one of the first generator or the second generator.
12. 12. An apparatus for processing a substrate in a plasma processing system, the apparatus comprising: one or more sensors configured to sense one or more intermodulation or harmonic components of a signal at a node coupled to the plasma chamber; one or more signal processing devices coupled to the plasma chamber, and A controller configured to control the one or more signal processing devices of the plasma processing system to process the substrate based on the one or more intermodulation or harmonic components and according to a frequency domain configuration identified by analyzing one or more substrate processing metrics.
13. 13. The apparatus of claim 12, wherein the frequency domain configuration includes a ratio between magnitudes of at least two intermodulation or harmonic components.
14. 14. The apparatus of claim 12, wherein the one or more substrate processing metrics comprise process variation, etch rate, or uniformity associated with substrate processing.
15. 15. The apparatus of claim 12, wherein the controller is further configured to construct a Pulse Voltage (PV) waveform based on the sensed one or more intermodulation or harmonic components, wherein the one or more signal processing devices are controlled based on the constructed PV waveform.
16. 16. The apparatus of claim 15, wherein the one or more signal processing devices include at least one of a PV waveform generator or a Radio Frequency (RF) generator configured to be controlled based on the constructed PV waveform.
17. 17. The apparatus of claim 12, wherein the one or more signal processing devices comprise a matching circuit, and wherein the node coupled to the plasma chamber comprises an output of the matching circuit.
18. 18. The apparatus of claim 17, wherein the node coupled to the plasma chamber is external to the matching circuit.
19. 19. The apparatus of claim 12, wherein to control the one or more signal processing devices, the controller is configured to control at least one of a magnitude or a phase of one or more output signals of the one or more signal processing devices.
20. 20. The apparatus of claim 12, wherein the one or more signal processing means comprises: first matching circuit A second matching circuit, wherein the one or more sensors include a sensor coupled to outputs of the first matching circuit and the second matching circuit.

Description

Radio Frequency (RF) matching network and tuning technique Technical Field Embodiments of the present invention generally relate to systems and methods for use in semiconductor device fabrication. More particularly, embodiments of the invention relate to a plasma processing system for processing a substrate. Background Reliably producing high aspect ratio features is one of the key technical challenges for next generation semiconductor devices. One method of forming high aspect ratio features uses a plasma assisted etching process, such as a Reactive Ion Etching (RIE) plasma process, to form high aspect ratio openings in a material layer of a substrate, such as a dielectric layer. In a typical RIE plasma process, a plasma is formed in a process chamber and ions from the plasma are accelerated toward the surface of the substrate to form openings in a material layer disposed below a mask layer formed on the surface of the substrate. A typical RIE plasma processing chamber includes a Radio Frequency (RF) bias generator that supplies an RF voltage to a power electrode. In capacitively coupled gas discharge, the plasma is generated by using an RF generator that is coupled to a power electrode disposed within an electrostatic chuck (ESC) assembly or another portion of the process chamber. Typically, an RF matching network ("RF matching") tunes the RF waveform provided from the RF generator to deliver RF power to an apparent load of 50 Ω to minimize reflected power and maximize power delivery efficiency. If the impedance of the load is not properly matched to the impedance of the source (e.g., RF generator), a portion of the forward-delivered RF waveform may be reflected back along the same transmission line in the opposite direction. Accordingly, there is a need for an apparatus and method for processing a substrate in a plasma processing system that solves the above-described problems. Disclosure of Invention Embodiments provided herein generally include apparatus, plasma processing systems, and tuning methods for improving substrate processing metrics in a Radio Frequency (RF) plasma processing system. Some embodiments are directed to a method for processing a substrate in a plasma processing system. The method generally includes sensing, by one or more sensors, one or more intermodulation or harmonic components of a signal at a node coupled to a plasma chamber, and controlling one or more signal processing devices of the plasma processing system to process the substrate based on the one or more intermodulation or harmonic components and according to a frequency domain configuration identified by analyzing one or more substrate processing metrics. Some embodiments are directed to an apparatus for processing a substrate in a plasma processing system. The apparatus generally includes one or more sensors configured to sense one or more intermodulation or harmonic components of a signal at a node coupled to a plasma chamber, one or more signal processing devices coupled to the plasma chamber, and a controller configured to control the one or more signal processing devices of the plasma processing system to process the substrate based on the one or more intermodulation or harmonic components and according to a frequency domain configuration identified by analyzing one or more substrate processing metrics. Some embodiments are directed to a plasma processing system comprising a plasma chamber, one or more sensors configured to sense one or more intermodulation or harmonic components of a signal at a node coupled to the plasma chamber, one or more signal processing devices coupled to the plasma chamber, and a controller configured to control the one or more signal processing devices of the plasma processing system to process the substrate based on the one or more intermodulation or harmonic components and in accordance with a frequency domain configuration identified by analyzing one or more substrate processing metrics. Drawings So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. FIG. 1A is a schematic diagram of a plasma processing system according to some embodiments of the invention. Fig. 1B is a detailed cross-sectional schematic view of a plasma processing system according to some embodiments of the invention. Fig. 2 illustrates voltage waveforms established on a substrate due to voltage waveforms applied to electrodes of a process chamber, according to some embodiments of the invention. Fig. 3 is a schematic diagram of a Radio Frequency (RF) matching network in accordan