Dual RF Power Supply Impedance Control for Etching
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Solution Overview
Problem
Existing substrate processing apparatuses face challenges in stabilizing load power in radio-frequency power supplies, particularly in achieving optimal impedance matching for efficient plasma generation and ion implantation, which affects etching rates and plasma electron densities.
Innovation Solution
A substrate processing apparatus is designed with a first radio-frequency power supply, an impedance converter, and a controller that sets the impedance to specific values based on the substrate processing requirements, allowing for simultaneous supply of radio-frequency powers at different frequencies to optimize impedance matching and adjust the timing of power supply to enhance etching efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single radio-frequency power supply is used for substrate processing, then the device complexity is reduced, but the ability to optimize impedance matching and control plasma generation is insufficient
Solution Approach 1:
The radio-frequency power supply system is segmented into multiple independent power supplies operating at different frequencies. The first radio-frequency power supply operates at a first frequency for plasma generation, while the second radio-frequency power supply operates at a second frequency for ion implantation. This segmentation allows each power supply to be independently optimized for its specific function, improving overall system adaptability without requiring a single complex multi-functional power supply.
Solution Approach 2:
The substrate processing apparatus is designed with multi-functionality by incorporating multiple radio-frequency power supplies that can perform different functions simultaneously. The system can perform plasma generation, ion implantation, and etching processes using the respective power supplies at different frequencies, making the apparatus universally applicable for various substrate processing operations.
2Manufacturing precision
If impedance is fixed for radio-frequency power supply, then the device complexity is reduced, but the etching rate and plasma electron density cannot be optimized for different processing requirements
Solution Approach 1:
The impedance converter is designed with dynamic adjustment capability, allowing the impedance value to be changed based on processing requirements. The impedance converter includes variable capacitors or inductors that can be adjusted to change the impedance value, enabling real-time optimization of plasma generation and ion implantation efficiency for different etching processes.
Solution Approach 2:
The system changes the impedance parameter dynamically to optimize processing outcomes. By adjusting the impedance value through the impedance converter, the system can control the amount of radio-frequency power delivered to the substrate, thereby controlling etching rates and plasma electron density according to specific processing requirements.
3Reliability
If radio-frequency power is supplied continuously, then the productivity is improved, but the control over plasma generation and ion implantation timing is reduced
Solution Approach 1:
The system employs periodic action by controlling the timing of radio-frequency power supply from multiple power supplies. The first radio-frequency power supply for plasma generation and the second radio-frequency power supply for ion implantation can be activated in alternating periods or simultaneously with controlled phase relationships, enabling precise control over processing stages while maintaining overall productivity.
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 configuration improves etching rates and plasma electron densities by adjusting impedance settings, allowing for precise control of the reflected wave timing and power distribution, thereby promoting efficient substrate processing.
Implementation Method 1
a first radio-frequency power supply configured to supply first radio-frequency power having a first frequency to the substrate stage
Implementation Method 2
a second radio-frequency power supply configured to supply second radio-frequency power having a second frequency lower than the first frequency to the substrate stage
Implementation Method 3
an impedance converter configured to convert an impedance on a load side seen from the first radio-frequency power supply into a set impedance
Data Source
AI summary
A substrate processing apparatus includes a substrate stage on which a substrate is disposed, a first radio-frequency power supply configured to supply first radio-frequency power having a first frequency to the substrate stage, an impedance converter configured to convert an impedance on a load side seen from the first radio-frequency power supply into a set impedance, a second radio-frequency power supply configured to supply second radio-frequency power having a second frequency lower than the first frequency to the substrate stage, and a controller configured to control the set impedance of the impedance converter, and the controller sets the set impedance according to a substrate processing.