Wafer Plasma Phase Shifting to Eliminate Chamber Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wafer processing apparatuses with shared platforms and reaction chambers experience issues such as low plasma quality, instability, and center plasma interference due to interactions among plasma waves, affecting wafer processing quality.
Innovation Solution
A wafer processing system with independently adjustable plasma phases in each reaction chamber, using a control circuit to shift the plasma phase by specific degrees among the chambers to achieve destructive interference and eliminate center plasma, thereby enhancing plasma stability and wafer quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If plasma is fed into multiple reaction chambers on a shared platform with the same frequency and phase, then all chambers can operate simultaneously, but center plasma interference and unstable plasma occur due to constructive interference among plasma waves
Solution Approach 1:
The patent changes the phase parameter of plasma fed into each reaction chamber. Specifically, it feeds plasma with different phases into adjacent reaction chambers (e.g., 0°, 120°, 240° phases for three chambers, or 0° and 180° phases for two chambers) to transform constructive interference into destructive interference, eliminating center plasma interference while maintaining simultaneous operation of all chambers
2Device complexity
If the same phase plasma is provided to all reaction chambers, then the system configuration is simple, but center plasma interference occurs due to constructive interference
Solution Approach 1:
The patent introduces phase as a controllable parameter in the plasma feeding system. By equipping each plasma generator or feeding path with independent phase control capability, the system can adjust plasma phases to different values (0°, 120°, 240° or 0° and 180°) without significantly increasing hardware complexity, thereby eliminating center plasma interference through destructive interference
3Ease of operation
If plasma with identical phase is fed to all chambers, then plasma generation is uniform across chambers, but low plasma window and poor repeatability occur due to plasma interactions
Solution Approach 1:
The patent changes the phase parameter of plasma fed into each reaction chamber to different values (e.g., 0°, 120°, 240° phases). This phase differentiation prevents harmful interactions among plasma waves while maintaining uniform plasma generation in each chamber, thereby improving wafer processing repeatability and eliminating issues like low plasma window
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 phase shifting technique effectively minimizes center plasma interference, stabilizes plasma performance, and improves wafer quality by creating destructive interference instead of constructive, resulting in more stable and efficient plasma processing across reaction chambers.
Implementation Method 1
a plasma generator configured to generate plasma with a certain frequency and a certain phase
Implementation Method 2
the control circuit is further configured to shift the phase of the generated plasma provided to the first reaction chamber, the second reaction chamber, the third reaction chamber, and the fourth reaction chamber, independently
Implementation Method 3
shift the phase of the plasma provided to the second reaction chamber is 90 degrees ahead of that provided to the first reaction chamber... resulting in destructive interference instead of constructive
Data Source
AI summary
A wafer processing system using plasma would be presented. The system may comprise a plurality of reaction chambers disposed on a platform, each of them being configured to process wafers; a plasma generator coupled to the plurality of reaction chambers individually and configured to generate plasma with a certain frequency and a certain phase, and further configured to provide the generated plasma to the plurality of reaction chambers; and a control circuit connected to the plasma generator and configured to adjust the phase of the plasma generated by the plasma generator; wherein, the control circuit is further configured to shift the phase of the generated plasma provided to the plurality of reaction chambers independently.