Air-Cooled Faraday Shield Hub for Plasma Deposition Flaking
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Solution Overview
Problem
In semiconductor manufacturing, Faraday shields in plasma etching chambers face issues with deposition buildup and temperature cycling, leading to flaking or peeling of coatings, which can result in particle contamination and defects on wafers, requiring frequent cleaning.
Innovation Solution
A system and method involving a hub with an internal plenum that interfaces with the Faraday shield to control its temperature through airflow, using compressed dry air or air amplifiers to reduce thermal cycling and maintain a stable temperature, thereby preventing deposition flaking and extending the shield's lifespan.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a Faraday shield is utilized inside the chamber to block deposition onto the window, then the window is protected from deposition, but the deposition builds up on the Faraday shield leading to particles flaking off
Solution Approach 1:
The harmful deposition is extracted from the window surface and redirected to accumulate on the Faraday shield instead, where it can be managed through controlled removal processes
Solution Approach 2:
The Faraday shield acts as an intermediary component that intercepts deposition materials before they reach the window, serving as a sacrificial surface that protects the critical window from contamination
2Productivity
If the Faraday shield is subjected to excessive temperatures for extended periods, then the etching process can be maintained, but the coating on the Faraday shield peels off
Solution Approach 1:
A cooling system is pre-installed and activated before excessive temperature buildup occurs, preventing the coating peeling issue before it starts by maintaining safe operating temperatures throughout the etching process
Solution Approach 2:
Temperature monitoring and control systems provide feedback to adjust cooling airflow dynamically, ensuring the Faraday shield operates within safe temperature ranges that prevent coating degradation while maintaining etching productivity
3Reliability
If the chamber is cleaned frequently to remove deposition from the Faraday shield, then particle contamination is reduced, but production time is lost
Solution Approach 1:
The cooling system operates continuously during etching processes to prevent deposition buildup that would require cleaning, maintaining shield temperature control throughout production to enable longer intervals between cleaning cycles
Solution Approach 2:
By changing the temperature parameter of the Faraday shield through active cooling, the rate of deposition accumulation is reduced, extending the time between necessary cleaning operations and maintaining wafer quality over longer production periods
4Power
If TCP coils deliver power to heat the chamber, then the etching process is enabled, but thermal cycling causes flaking or peeling of deposition material
Solution Approach 1:
Cooling is applied locally to the Faraday shield and window areas most susceptible to thermal cycling damage, creating temperature gradients that stabilize deposition in critical regions while allowing the bulk chamber to undergo necessary thermal cycles for the etching process
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 controlled airflow system effectively reduces the Faraday shield's temperature and minimizes thermal cycling, preventing deposition flaking and enhancing the reliability of the etching process by maintaining a stable environment, thus reducing the need for frequent cleaning and extending the shield's operational life.
Implementation Method 1
The embodiments defined herein provide methods and structures for controlling and/or maintaining the temperature of the Faraday shield for successful operation and minimize thermal cycling issues
Implementation Method 2
A system and method involving a hub with an internal plenum that interfaces with the Faraday shield to control its temperature through airflow
Data Source
AI summary
A chamber is provided. The chamber includes a Faraday shield positioned above a substrate support of the chamber. A dielectric window is disposed over the Faraday shield, and the dielectric window has a center opening. A hub having an internal plenum for passing a flow of fluid received from an input conduit and removing the flow of fluid from an output conduit is further provided. The hub has sidewalls and a center cavity inside of the sidewalls for an optical probe, and the internal plenum is disposed in the sidewalls. The hub has an interface surface that is in physical contact with a back side of the Faraday shield. The physical contact provides for a thermal couple to the Faraday shield at a center region around said center opening, and an outer surface of the sidewalls of the hub are disposed within the center opening of the dielectric window.