Plasma Mounting Table Groove Segmentation for Thermal Control
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Solution Overview
Problem
Current plasma processing apparatuses face challenges in independently controlling the temperature of a target object and a focus ring, generating a significant temperature difference between them while avoiding thermal stress deformation, and maintaining a uniform sheath field, due to thermal interference and differences in thermal expansion.
Innovation Solution
A mounting table design with a base member divided into inner and outer portions by a groove, where the target object and focus ring are thermally separated, allowing independent temperature control and connecting the base member portions as a RF circuit for uniform power distribution, with heat transfer members between the mounting surface and coolant paths to manage temperature differences and thermal stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single base member is used to support both the target object and focus ring, then the structure is simple, but thermal interference occurs between the target object and focus ring making independent temperature control difficult
Solution Approach 1:
The base member is divided into an inner base member portion and an outer base member portion by a groove portion. The inner portion supports the target object while the outer portion supports the focus ring, physically separating the thermal fields of both components to enable independent temperature control
2Temperature
If a groove portion is introduced to thermally separate the inner and outer base member portions, then independent temperature control is achieved, but the structure becomes more complex
Solution Approach 1:
The groove portion creates a physical segmentation in the base member that thermally isolates the inner and outer portions while maintaining structural integrity. This segmentation allows independent temperature control without requiring completely separate base members
Solution Approach 2:
The groove portion acts as a thermal intermediary or barrier between the inner and outer base member portions. It prevents direct thermal conduction while allowing the structure to remain unified, enabling independent temperature zones
3Stability of the object's composition
If the inner and outer base member portions are thermally separated, then thermal stress deformation is suppressed, but maintaining uniform sheath field becomes more difficult
Solution Approach 1:
The groove portion serves as a thermal barrier that reduces thermal stress deformation while the RF circuit connection maintains electrical continuity. This dual function allows both thermal stress resistance and sheath field uniformity to be achieved
4Manufacturing precision
If temperature difference between target object and focus ring is increased, then process accuracy is improved, but thermal stress deformation increases
Solution Approach 1:
By segmenting the base member into thermally isolated inner and outer portions, the patent enables large temperature differences between target object and focus ring without creating excessive thermal stress in a unified structure. Each portion can expand or contract independently
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
Enables independent control of target object and focus ring temperatures, suppressing thermal interference and stress deformation, and generating a uniform sheath field, thus improving process accuracy and preventing component damage.
Implementation Method 1
a groove portion having a bottom surface within the base member is annularly formed on the front surface... the base member is divided into a cylindrical inner base member portion positioned at an inner side of the groove portion and an annular outer base member portion positioned at an outer side of the groove portion by the groove portion
Implementation Method 2
a first heat transfer member is provided between the mounting surface and the coolant path... a second heat transfer member is provided between the focus ring and the coolant path
Implementation Method 3
The groove portion allows a RF power supply to apply a voltage to the base member, thereby generating a uniform sheath field on a surface of the target object and a surface of the focus ring
Data Source
AI summary
A mounting table includes a base member, having a rear surface and a front surface facing the rear surface, in which a coolant path is formed, a groove portion having a bottom surface within the base member being annularly formed on the front surface, the base member being divided into a cylindrical inner base member portion positioned at an inner side of the groove portion and an annular outer base member portion positioned at an outer side of the groove portion by the groove portion; an annular focus ring supported by the outer base member portion, the annular focus ring having, at an inner side surface thereof, a protrusion that is protruded radially and inwardly to cover the groove portion; a first heat transfer member provided between the mounting surface and the coolant path; and the second heat transfer member provided between the focus ring and the coolant path.