Plasma Processing Controller Using Focus Ring DC Potential Feedback
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Solution Overview
Problem
Current plasma etching technologies face challenges in controlling the etching rate effectively, which affects the precision and efficiency of the process.
Innovation Solution
A plasma processing apparatus with a controller that adjusts the bias radio-frequency power supply based on the DC potential of a focus ring, using a table or function to specify the power level, ensuring accurate control of the etching rate by maintaining a linear relationship between the DC potential and the power level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the bias radio-frequency power level is adjusted to control the etching rate, then the etching rate can be modified, but the controllability and precision of the etching rate adjustment is insufficient
Solution Approach 1:
The patent implements a feedback control mechanism where the DC potential of the focus ring is measured and used to adjust the bias radio-frequency power level. The controller continuously monitors the DC potential and modifies the power supply output to maintain the desired etching rate, creating a closed-loop control system that improves both precision and controllability.
Solution Approach 2:
The patent introduces the DC potential of the focus ring as an intermediary parameter that mediates between the bias radio-frequency power level and the etching rate. By controlling the DC potential through power level adjustment, the system achieves more precise etching rate control than direct power adjustment alone.
2Manufacturing precision
If a direct relationship between bias radio-frequency power level and etching rate is used, then the control system is simple, but the accuracy of achieving desired etching rates is insufficient
Solution Approach 1:
The controller uses feedback from DC potential measurements to accurately determine the actual etching rate condition and adjusts the bias radio-frequency power accordingly, achieving high etching rate accuracy without requiring complex additional hardware.
Solution Approach 2:
The patent replaces direct mechanical/power control with an electrical measurement and control approach. By substituting the direct power-etching rate relationship with an electrical DC potential measurement system, the invention achieves higher precision while keeping the overall system complexity manageable through electronic control.
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 approach enhances the controllability of the etching rate, allowing for precise adjustment and high accuracy in achieving desired etching rates, even with changes in the plasma processing apparatus state.
Implementation Method 1
The radio-frequency power supply is configured to supply a bias radio-frequency power to the lower electrode
Implementation Method 2
In manufacturing electronic devices, plasma etching is performed on a substrate. The plasma etching is performed by a plasma processing apparatus.
Implementation Method 3
the energy of ions attracted from plasma to the substrate is adjusted by a power level of the bias radio-frequency power
Data Source
AI summary
A plasma processing apparatus includes a chamber, a substrate support, a radio-frequency power supply, and a controller. The substrate support includes a lower electrode and is disposed in the chamber to mount a focus ring to surround a disposed substrate on the substrate support. The radio-frequency power supply supplies a bias radio-frequency power to the lower electrode. The controller causes specifying a power level of the bias radio-frequency power corresponding to a specified value of the DC potential of the focus ring by using a table or a function that defines a relationship between the power level of the bias radio-frequency power and the DC potential of the focus ring generated by supplying the bias radio-frequency power to the lower electrode, and controlling the radio-frequency power supply to supply the bias radio-frequency power having the specified power level to the lower electrode during a plasma generation in the chamber.