Matchless Plasma Source With Agile DC Rail for Fast Plasma Ignition
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Solution Overview
Problem
Current plasma processing systems using RF generators, RF cables, and RF matches are limited by high costs, slow impedance tuning, and limited capabilities in generating advanced pulses, which hinder plasma ignition speed and uniformity.
Innovation Solution
A matchless plasma source utilizing low impedance voltage sources, such as FETs or IGBTs, operated in a half-bridge configuration, coupled directly to an electrode, which eliminates the need for RF matches and cables, enabling faster impedance tuning and advanced pulse generation through an agile DC rail for efficient plasma ignition and sustainment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If RF generator, RF cable, and RF match are used to deliver power to plasma chamber, then power delivery is achieved, but cost increases and plasma ignition speed decreases
Solution Approach 1:
The patent extracts and removes the RF match and RF cable from the traditional power delivery system, replacing them with a direct connection from the RF generator to the plasma chamber electrode. This elimination of intermediate components reduces system cost and simplifies the power delivery path, enabling faster plasma ignition while maintaining effective power transfer.
Solution Approach 2:
The patent merges the RF generator and plasma chamber into a more integrated configuration by eliminating the RF cable and RF match interface. The RF generator is directly coupled to the plasma chamber electrode, creating a unified power delivery system that reduces component count, lowers cost, and improves ignition speed through reduced signal path length and impedance interfaces.
2Productivity
If RF match is used to transform impedance, then power delivery is optimized, but impedance tuning speed decreases
Solution Approach 1:
The patent removes the RF match component entirely from the system, eliminating the impedance transformation interface that previously limited tuning speed. By directly coupling the RF generator to the plasma chamber electrode, the system achieves impedance matching through direct control without the mechanical or electronic adjustments required by an RF match, thereby dramatically increasing impedance tuning speed.
Solution Approach 2:
The patent implements dynamic impedance control by directly coupling the RF generator to the plasma chamber, allowing real-time adjustment of power delivery parameters without the lag associated with RF match tuning mechanisms. This dynamic configuration enables rapid adaptation to changing plasma conditions, improving productivity through faster impedance optimization.
3Adaptability or versatility
If traditional RF system is used, then plasma generation is achieved, but capability to generate advanced pulses is limited
Solution Approach 1:
The patent merges the RF generator with advanced pulse generation circuitry, integrating multiple functions into a unified system. The direct coupling between the RF generator and plasma chamber enables sophisticated pulse shaping and modulation capabilities that are not achievable with traditional RF cable and RF match configurations, thereby enhancing adaptability for advanced plasma processing applications.
Solution Approach 2:
The patent creates a multi-functional power delivery system where the RF generator directly coupled to the plasma chamber can perform both traditional continuous wave operation and advanced pulsed operation. This universal configuration eliminates the need for separate pulse generation equipment, providing versatile pulse generation capabilities while simplifying the overall system configuration.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution reduces costs, enhances plasma ignition speed, and improves impedance tuning speed, allowing for more advanced pulse capabilities and better plasma uniformity, leading to efficient and stable plasma processing.
Implementation Method 1
Power transistors, such as field-effect transistors (FETs) or insulated-gate bipolar transistors (IGBTs), which are operated as a low impedance voltage source to couple power to the electrode
Implementation Method 2
A plasma system is used to perform a variety of operations on wafers. The plasma system includes a radio frequency (RF) generator, an RF match, and a plasma chamber. An RF power is provided via the RF cable and the RF match to the plasma chamber in which a wafer is processed. Also, one or more gases are supplied to the plasma chamber and upon reception of the RF power, plasma is generated within the plasma chamber.
Data Source
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Figure 3A
AI summary
A matchless plasma source is described. The matchless plasma source includes a controller that is coupled to a direct current (DC) voltage source of an agile DC rail to control a shape of an amplified square waveform that is generated at an output of a half -bridge transistor circuit. The matchless plasma source further includes the half-bridge transistor circuit used to generate the amplified square waveform to power an electrode, such as an antenna, of a plasma chamber. The matchless plasma source also includes a reactive circuit between the half-bridge transistor circuit and the electrode. The reactive circuit has a high- quality factor to negate a reactance of the electrode. There is no radio frequency (RF) match and an RF cable that couples the matchless plasma source to the electrode.