Plasma Generator Impedance Control for Semiconductor Substrate Processing
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Solution Overview
Problem
In substrate processing for semiconductor device manufacturing, plasma electrode deterioration leads to fluctuations in active species distribution and potential abnormal discharges, making uniform substrate processing challenging.
Innovation Solution
A substrate processing apparatus equipped with a plasma generator connected to a high-frequency power source, an impedance meter to measure plasma impedance, and a controller to adjust power based on measured impedance, ensuring consistent active species generation and preventing electrode deterioration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If plasma processing is performed using a conventional plasma generator, then substrate processing can be carried out, but electrode deterioration occurs leading to fluctuations in active species distribution and abnormal discharges
Solution Approach 1:
The patent implements a feedback control system where the impedance of the plasma generator is continuously monitored during substrate processing. The controller adjusts the high frequency power source based on impedance changes to maintain optimal plasma conditions. This feedback mechanism compensates for electrode deterioration in real-time, preventing fluctuations in active species distribution and abnormal discharges, thereby maintaining plasma processing stability throughout the electrode's service life.
Solution Approach 2:
The patent performs preliminary impedance measurement and analysis before substrate processing begins. The controller determines the optimal high frequency power settings based on pre-measured impedance values. This preliminary action allows the system to be pre-configured with appropriate power parameters that account for the current electrode condition, preventing processing issues before they occur.
2Quantity of substance
If high frequency power is increased to maintain plasma characteristics, then active species generation is improved, but electrode deterioration accelerates
Solution Approach 1:
The patent employs dynamic adjustment of high frequency power based on real-time impedance measurements. Instead of using a fixed high power setting, the controller continuously adapts the power level to match the current electrode condition and plasma state. This dynamic approach maintains sufficient active species generation while avoiding excessive power that would accelerate electrode deterioration, thereby extending electrode service life.
Solution Approach 2:
The patent changes the operating parameters (high frequency power level) based on measured impedance values. By monitoring impedance changes that indicate electrode deterioration, the system adjusts power parameters to maintain optimal active species generation without applying excessive stress to the electrodes, thus balancing processing quality with electrode longevity.
3Stability of the object's composition
If impedance monitoring and power adjustment are implemented, then plasma characteristics are stabilized, but device complexity increases
Solution Approach 1:
The patent integrates multiple functions into existing system components. The impedance measurement function is incorporated into the existing plasma generator structure, and the controller performs both impedance analysis and power source adjustment functions. This multi-functionality approach stabilizes plasma characteristics without requiring entirely separate dedicated components for each function, thereby limiting the increase in device complexity.
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 setup stabilizes plasma characteristics, improves film-forming and etching processes, and enhances the productivity and stability of wafer processing by maintaining optimal plasma conditions.
Implementation Method 1
a plasma generator configured to plasma-excite the gas supplied into the process chamber
Implementation Method 2
an impedance meter configured to measure an impedance of the plasma generator
Data Source
AI summary
Described herein is a technique capable of uniformly processing substrates. According to the technique described herein, there is provided a substrate processing apparatus including: a process chamber where a substrate is processed; a gas supply configured to supply a gas into the process chamber; a plasma generator configured to plasma-excite the gas supplied into the process chamber, the plasma generator including an electrode electrically connected to a high frequency power source; an impedance meter configured to measure an impedance of the plasma generator; a determiner configured to determine an amount of active species generated by the plasma generator based on the impedance measured by the impedance meter; and a controller configured to control the high frequency power source based on the amount of active species determined by the determiner.