Plasma Chamber Gas Supply Unit for Controlled Wafer Injection
Solution Overview
Problem
In ICP type plasma chambers used for semiconductor processing, the low pressure and high gap structure lead to uncontrolled gas dispersion, causing injected gases to scatter and disperse rather than being effectively directed onto the wafer surface, limiting process control.
Innovation Solution
A device that injects a mixed gas, composed of reactive and inert gases, into the plasma chamber at controlled pressures and directions, using a gas supply unit with inert gas supply lines, reactive gas supply lines, and mixed gas supply lines, with flow rate and pressure controllers to ensure precise gas distribution and prevent Knudsen flow.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If gas is injected into the plasma chamber at low pressure, then the chamber maintains stable plasma conditions, but the gas disperses uncontrollably and fails to reach the wafer surface effectively
Solution Approach 1:
A flow rate controller is introduced as an intermediary device between the gas supply and the plasma chamber. This controller actively regulates the gas flow rate, serving as a mediator that balances the conflicting requirements of maintaining low pressure for plasma stability while ensuring sufficient gas delivery to the wafer surface despite dispersion effects
Solution Approach 2:
The system dynamically adjusts the gas flow rate parameter based on process conditions. By changing the flow rate parameter through the flow rate controller, the system optimizes gas delivery effectiveness while maintaining the low pressure environment necessary for stable plasma operation
2Temperature
If a temperature control system is used to control the electrostatic chuck, then the wafer temperature is maintained, but the gas dispersion control ability is limited
Solution Approach 1:
The gas control function is segmented from the temperature control system. Instead of relying solely on temperature control to indirectly affect gas behavior, the patent introduces a dedicated flow rate control system that directly manages gas delivery, separating these two control functions to achieve independent optimization of both temperature stability and gas dispersion control
Solution Approach 2:
A flow rate controller is introduced as an intermediary device that directly controls gas flow parameters. This intermediary system bridges the gap between gas supply and plasma chamber, providing precise control over gas dispersion independent of the temperature control system
3Manufacturing precision
If the gas injection pressure is increased to improve gas delivery to the wafer, then gas dispersion control improves, but the plasma chamber pressure stability is compromised
Solution Approach 1:
The system optimizes the gas flow rate parameter within the existing low pressure regime. Rather than increasing chamber pressure, the flow rate controller adjusts the flow characteristics to improve gas delivery effectiveness while maintaining the pressure conditions necessary for stable plasma operation
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 controlled injection of mixed gases at higher pressures and adjusted flow rates allows for improved gas dispersion and control, ensuring that gases reach the wafer surface effectively, enhancing the reproducibility and reliability of semiconductor processes.
Implementation Method 1
The pressure of the mixed gas is increased by adding inert gas to reactive gas
Implementation Method 2
a flow rate controller coupled to the first mixed injection portion for adjusting flow rate of mixed gas through the inlet hole
Implementation Method 3
A pressure controller is coupled to the mixed gas supply line for controlling pressure of the mixed gas
Data Source
AI summary
A plasma processing device is provided with a chamber including a space that is configured to perform a treatment process for a wafer. A supporting member is disposed inside of the chamber and configured to support the wafer. A gas supply unit is configured to inject a mixed gas in different directions toward the supporting member. The pressure of the mixed gas is increased by adding inert gas to reactive gas.