Plasma Processing Control for Gas Switching Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma processing methods face challenges in achieving high shape controllability and stability due to machine differences in responsiveness between plasma processing apparatuses, leading to variations in treatment time and reduced mass production stability, particularly when switching between etching and deposition gases.
Innovation Solution
A plasma processing apparatus with a control device that adjusts the radio frequency power supply times based on plasma impedance changes during gas switching, ensuring that the supply times of the radio frequency power match the corresponding gas supply times, thereby minimizing machine differences and maintaining consistent treatment conditions across multiple devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If gas introduction time is shortened to 1-3 seconds to prevent scalloping, then shape controllability is improved, but machine differences in responsiveness cause variations in treatment time
Solution Approach 1:
The control device performs preliminary actions by detecting gas introduction timing in real-time and proactively adjusting process parameters before the actual gas switching occurs. This anticipatory control compensates for the short gas introduction time (1-3 seconds) and eliminates the impact of machine responsiveness differences, ensuring consistent treatment results across multiple apparatuses.
Solution Approach 2:
The control device implements feedback control by continuously monitoring the actual gas introduction timing and using this information to dynamically adjust process parameters. This closed-loop control ensures that despite variations in machine responsiveness, the treatment time and conditions remain consistent, thereby improving mass production stability while maintaining the short gas introduction time needed for shape controllability.
2Ease of operation
If control is performed without considering gas introduction delay, then control simplicity is improved, but a time gap is generated between gas introduction and parameter control
Solution Approach 1:
The control device replaces complex mechanical timing coordination with automated electronic control. By using a control device that automatically detects gas introduction timing and adjusts parameters accordingly, the system eliminates the need for manual timing coordination while maintaining high precision. This substitution of electronic feedback control for mechanical timing ensures both control simplicity and process timing accuracy.
3Stability of the object's composition
If radio frequency power is changed based on gas switching timing, then process synchronization is improved, but machine differences in gas supply responsiveness cause applying time variations
Solution Approach 1:
The control device uses feedback control to detect the actual gas introduction timing and adjusts the radio frequency power application timing accordingly. This real-time feedback mechanism compensates for machine differences in gas supply responsiveness, ensuring that the radio frequency power is applied at the correct moment relative to the actual gas presence in the processing chamber, thereby maintaining both process synchronization and applying time consistency.
Solution Approach 2:
The control device performs preliminary detection of gas introduction timing and proactively adjusts radio frequency power parameters before the actual processing occurs. This anticipatory control ensures that the radio frequency power application is synchronized with the actual gas switching, eliminating variations caused by machine responsiveness differences and maintaining consistent applying times across multiple apparatuses.
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 enables high shape controllability and reduced machine differences in radio frequency power application times among plasma processing apparatuses, enhancing the stability and consistency of plasma etching processes during gas switching.
Implementation Method 1
a first radio frequency power source configured to supply a first radio frequency power for generating a plasma
Implementation Method 2
when a first gas that is a gas for a first step is switched to a second gas that is a gas for a second step, the first radio frequency power is changed from a value of the first radio frequency power in the first step to a value of the first radio frequency power in the second step
Data Source
AI summary
A plasma processing apparatus, including a processing; a first radio frequency power source; a sample stage on which the sample is placed; a second radio frequency power; and a control device configured to control, when the second radio frequency power source is controlled based on a change in a plasma impedance, which is generated when a first gas that is a gas for a first step is switched to a second gas that is a gas for a second step, such that the second radio frequency power is changed from a value of the second radio frequency power in the first step to a value of the second radio frequency power in the second step, and a supply time of the first gas such that a supply time of the second radio frequency power in the first step is substantially equal to a time of the first step.