Plasma Chamber Dome Heating With Thermal Pads
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Solution Overview
Problem
Conventional plasma processing apparatuses face inefficiencies in heating the processing chamber dome to a set point temperature due to poor heat transfer between heating elements and the dome, leading to prolonged heating times and potential instability during processing.
Innovation Solution
A thermal management system with heating elements and thermal pads that eliminate air gaps between the dome and heating elements, coupled with a closed-loop control system to maintain set point temperature, facilitating efficient heat transfer and rapid heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional heating elements are used to heat the dome, then heating can be performed, but heat transfer efficiency is poor leading to prolonged heating times
Solution Approach 1:
A thermal pad is introduced as an intermediary component between the heating element and the dome. The thermal pad has high thermal conductivity and is configured to be in direct contact with both the heating element and the dome, facilitating efficient heat transfer from the heating element through the thermal pad to the dome, thereby eliminating air gaps and improving overall heat transfer efficiency
Solution Approach 2:
A vacuum system is employed to remove air from the chamber between the heating element and the dome. By creating a vacuum environment, the air gaps that impede heat transfer are eliminated, allowing for more efficient thermal coupling between the heating element and the dome surface
2Temperature
If pre-heating methods using heating elements are used, then the dome can be heated to set point temperature, but the process is time-consuming and costly
Solution Approach 1:
The thermal pad serves as a high-conductivity intermediary that rapidly conducts heat from the heating element to the dome, significantly reducing the time required to reach the set point temperature compared to conventional direct heating methods
Solution Approach 2:
The thermal properties of the heating system are changed by introducing the thermal pad with superior thermal conductivity parameters. This parameter change enables faster heat transfer rates, reducing the time required to achieve the desired dome temperature
3Loss of energy
If heating elements are placed close to the dome for efficient heat transfer, then heating efficiency improves, but air gaps cause heat loss and instability
Solution Approach 1:
The thermal pad acts as a stable intermediary that maintains consistent thermal coupling between the heating element and the dome. It eliminates air gaps that cause heat loss while providing a reliable, stable thermal pathway that ensures consistent heat transfer and temperature stability
Solution Approach 2:
A vacuum environment is created between the heating element and dome to eliminate air, which is an inert medium in this context. This removes convective heat loss pathways and provides a stable, predictable thermal environment for efficient and stable heating
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 system enables faster dome heating to and maintenance of set point temperatures without affecting plasma processing uniformity, reducing manufacturing time and costs by eliminating the need for dummy wafers.
Implementation Method 1
one or more thermal pads disposed between an outer surface of the dome and the heating elements, wherein substantially no air gas exist between the dome and the thermal pads and the heating elements and the thermal pads
Implementation Method 2
an induction coil assembly for producing a plasma in the processing chamber
Implementation Method 3
one or more heating elements configured to heat the dome
Data Source
AI summary
A plasma processing apparatus including a processing chamber having one or more sidewalls and a dome is provided. The plasma processing apparatus includes a workpiece support disposed in the processing chamber configured to support a workpiece during processing, an induction coil assembly for producing a plasma in the processing chamber, a Faraday shield disposed between the induction coil assembly and the dome, the Faraday shield comprising an inner portion and an outer portion, and a thermal management system. The thermal management system including one or more heating elements configured to heat the dome, and one or more thermal pads disposed between an outer surface of the dome and the heating elements, wherein the one or more thermal pads are configured to facilitate heat transfer between the one or more heating elements and the dome. Thermal management systems and methods for processing workpieces are also provided.