RF Power Compensation for Resistivity-Driven Plasma Rate Variation
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Solution Overview
Problem
Substrate processing systems face variations in deposition or etch rates due to variations in substrate bulk resistivity, leading to inconsistent processing results and increased costs from selecting and controlling substrate properties.
Innovation Solution
A substrate processing system that includes a plasma generator and sensor to sense RF power parameters, such as RF voltage, current, or phase angle, to compensate for variations in substrate bulk resistivity by adjusting the RF power during plasma processing, using a controller to maintain consistent deposition or etch rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If substrate bulk resistivity is controlled to ensure consistent processing rates, then deposition or etch rate uniformity is improved, but substrate selection complexity and processing costs increase
Solution Approach 1:
The system measures RF power parameters (voltage, current, or impedance) during plasma processing and uses this feedback to detect substrate bulk resistivity variations. The controller then dynamically adjusts RF power in real-time to compensate for resistivity differences, eliminating the need for pre-selection of substrates with specific resistivity values while maintaining consistent processing rates.
Solution Approach 2:
The system changes the RF power parameter dynamically during processing based on measured substrate resistivity. By adjusting RF power levels in response to detected resistivity variations, the system compensates for substrate differences and maintains uniform deposition or etch rates without requiring strict substrate resistivity control.
2Manufacturing precision
If RF power is adjusted dynamically to compensate for resistivity variations, then processing rate consistency is improved, but system complexity and measurement requirements increase
Solution Approach 1:
The system incorporates sensors to measure RF power parameters (voltage, current, or impedance) during plasma processing and feeds this information back to a controller. The controller uses this feedback to detect substrate resistivity variations and dynamically adjusts RF power accordingly, achieving consistent processing rates through a closed-loop control system.
Solution Approach 2:
The system replaces mechanical substrate selection and manual adjustment methods with automated electronic sensing and control. By using RF power parameter measurements and electronic feedback control, the system eliminates the need for physical substrate inspection and manual RF power adjustment, reducing operational complexity while improving precision.
3Manufacturing precision
If RF power parameters are sensed and adjusted in real-time, then deposition or etch rate variations are reduced, but measurement and control complexity increase
Solution Approach 1:
The system continuously measures RF power parameters (voltage, current, or impedance) during plasma processing and uses this real-time feedback to detect substrate resistivity variations. The controller processes these measurements and dynamically adjusts RF power accordingly, achieving precise control of deposition or etch rates through automated feedback loops that simplify the measurement and control process.
Solution Approach 2:
The system uses multi-functional RF power parameter sensing that can detect substrate resistivity variations through measurements of voltage, current, or impedance. This universal approach allows the same sensing system to serve multiple measurement purposes, reducing the complexity of implementing separate measurement systems for different parameters.
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
The system effectively reduces deposition or etch rate variations by up to 80% by dynamically adjusting RF power based on sensed parameters, ensuring uniform processing across substrates with different resistivity levels.
Implementation Method 1
A plasma generator is configured to supply (radio frequency) RF power to an electrode arranged in a processing chamber
Implementation Method 2
A sensor is configured to sense a parameter of the RF power supplied to the electrode
Implementation Method 3
Plasma may be struck to enhance chemical reactions within the processing chamber
Implementation Method 4
An RF bias may be supplied to the substrate support to control ion energy
Data Source
AI summary
A substrate processing system includes a plasma generator configured to supply (radio frequency) RF power to an electrode arranged in a processing chamber. A sensor is configured to sense a parameter of the RF power supplied to the electrode. A controller is configured to compensate variations in a rate of a plasma process due to variations in bulk resistivity of a substrate arranged on a substrate support by causing the sensor to sense the parameter at least one of prior to plasma processing of the substrate and after a predetermined period after the plasma processing of the substrate begins; and adjusting the parameter of the RF power for the substrate during the plasma processing of the substrate based on the parameter sensed for the substrate.