Microwave Transmitting Window Array for Plasma Uniformity
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Solution Overview
Problem
Existing plasma processing apparatuses face challenges in achieving uniform plasma distribution for large-sized wafers, requiring complex antenna redesigns and limited adjustment capabilities, which hampers productivity and process uniformity.
Innovation Solution
A plasma processing apparatus with a microwave introduction device featuring multiple microwave transmitting windows arranged in a specific configuration above the process chamber, ensuring equal distances between their centers to uniformly distribute plasma across the wafer surface, allowing for easy adjustment and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single planar antenna or coil antenna is used to generate plasma for large-sized wafers, then the process chamber can be simplified in structure, but the plasma distribution uniformity across the wafer surface deteriorates
Solution Approach 1:
The single antenna is divided into multiple antenna units arranged in an array. Each antenna unit independently generates plasma, and their combined effect achieves uniform plasma distribution across the large wafer surface without requiring a complex redesign of the entire antenna structure
Solution Approach 2:
Multiple antenna units are combined in an array configuration where their individual plasma generation capabilities are merged to cover the entire wafer surface uniformly, achieving both structural simplicity and plasma uniformity
2Manufacturing precision
If the slot shape or arrangement in a planar antenna is optimized to change plasma distribution, then plasma uniformity can be improved, but the device complexity and time required for redesign increase
Solution Approach 1:
Instead of changing the physical shape or arrangement of slots in the antenna structure, the invention achieves plasma distribution control by adjusting process parameters such as microwave power, process pressure, and flow rate, thereby avoiding complex antenna redesign
3Manufacturing precision
If process parameters such as microwave power, process pressure, and flow rate are adjusted to optimize plasma distribution, then plasma uniformity can be improved within a limited range, but the adjustment capability is constrained by process conditions
Solution Approach 1:
The single plasma generation source is segmented into multiple antenna units that can be independently controlled. This segmentation expands the adjustment capability by allowing individual units to be tuned separately, providing broader adaptability while achieving plasma uniformity
4Manufacturing precision
If the plasma distribution becomes eccentric due to manufacturing tolerance or assembly error, then process uniformity deteriorates, but there is no simple means for correction without replacing the antenna
Solution Approach 1:
When plasma distribution becomes eccentric, the invention allows for correction by adjusting process parameters such as microwave power distribution among antenna units, process pressure, and flow rate, providing a simple means to restore uniformity without antenna replacement
Solution Approach 2:
The system incorporates dynamic adjustment capability where process parameters can be modified in real-time to correct plasma distribution eccentricity, making the system adaptable to manufacturing variations without requiring physical antenna replacement
5Productivity
If wafer diameter is increased from 300 mm to 450 mm to improve productivity, then the processing area increases, but achieving plasma uniformity across the larger surface becomes more difficult
Solution Approach 1:
The antenna system is segmented into multiple antenna units arranged in an array that covers the larger 450 mm wafer surface. Each unit contributes to uniform plasma generation across the expanded area, maintaining plasma uniformity while improving productivity through larger wafer processing
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 configuration enables uniform plasma distribution with a simple structure, improving productivity and reducing the need for frequent antenna replacements, while allowing for flexible plasma density control across the wafer surface.
Implementation Method 1
a plurality of microwave transmitting windows 73 which are fitted into the respective openings and transmit and introduce the microwave into the process chamber
Implementation Method 2
a microwave introduction device for generating a microwave to produce plasma of the process gas in the process chamber
Data Source
AI summary
A plasma processing apparatus includes a microwave introduction device which introduces a microwave into a process chamber. The microwave introduction device includes a plurality of microwave transmitting plates which is fitted into a plurality of openings of a ceiling. The microwave transmitting plates are arranged on one virtual plane parallel to a mounting surface of a mounting table, with the microwave transmitting plates fitted into the respective openings. The microwave transmitting plates includes first to third microwave transmitting plates. The first to third microwave transmitting plates are arranged in such a manner that a distance between the center point of the first microwave transmitting window and the center point of the second microwave transmitting window becomes equal or approximately equal to a distance between the center point of the first microwave transmitting window and the center point of the third microwave transmitting window.