Plasma Chamber Liner with Integrated Flow Equalizer
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Solution Overview
Problem
Conventional plasma etch processes in integrated circuit manufacturing suffer from non-uniformity of etch rates across substrates due to uneven gas distribution, leading to decreased performance and increased fabrication costs.
Innovation Solution
An integrated flow equalizer is implemented in a plasma processing chamber, featuring a lower chamber liner with an elevated design and strategically arranged apertures to create a high conductance plenum, ensuring uniform gas flow and plasma distribution across the substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional plasma etch process is used with a vacuum pump drawing gas toward an exhaust port, then gas evacuation is achieved, but non-uniform gas flow distribution occurs causing non-uniform etching across the substrate
Solution Approach 1:
The lower chamber liner is segmented with multiple apertures distributed across its surface, dividing the gas flow path into multiple channels. This segmentation allows gas to be drawn through numerous small openings rather than a single large one, creating a more distributed flow pattern that reduces non-uniformity across the substrate
Solution Approach 2:
The apertures in the lower chamber liner have non-uniform distribution patterns, with different densities in different regions. This local variation in aperture density compensates for the natural gas flow gradients, providing enhanced gas flow uniformity in regions where it is most needed
2Manufacturing precision
If the lower chamber liner is positioned close to the chamber bottom wall, then chamber volume is reduced, but gas flow conductance is insufficient leading to poor plasma uniformity
Solution Approach 1:
The lower chamber liner is elevated vertically from the chamber bottom wall, creating a plenum space in the vertical dimension. This dimensional change provides a reservoir volume that improves gas flow conductance and plasma uniformity without significantly increasing the horizontal chamber footprint
Solution Approach 2:
The elevated lower chamber liner creates a nested plenum structure between itself and the chamber bottom wall. This nested configuration provides additional gas flow pathways and volume efficiency, improving conductance while maintaining compact chamber dimensions
3Manufacturing precision
If the lower chamber liner is elevated to create a high conductance plenum, then gas flow uniformity is improved, but device complexity increases
Solution Approach 1:
The lower chamber liner serves multiple functions: it protects the chamber bottom wall from plasma damage, acts as a gas distribution manifold through its apertures, and creates the elevated plenum structure for improved flow conductance. This multi-functionality reduces the need for separate components, offsetting the added structural complexity
Solution Approach 2:
The gas distribution function is merged into the lower chamber liner structure itself rather than being a separate component. The apertures are integrated directly into the liner, combining the protective barrier function with the gas flow distribution function in a single element
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 solution achieves uniform etching across the substrate, enhancing the performance and reducing fabrication costs by ensuring consistent gas flow and plasma distribution, thereby addressing the non-uniformity issues in conventional plasma etch processes.
Implementation Method 1
The lower chamber liner may be elevated from a chamber bottom wall to create a high conductance plenum between the lower chamber liner and the bottom wall
Implementation Method 2
The lower chamber liner may have an aperture formed therethrough configured to equalize the flow of processing gas drawn by a vacuum pump
Implementation Method 3
an apparatus for uniformly etching material layers during the manufacture of integrated circuits
Data Source
AI summary
A plasma processing chamber has a lower liner with an integrated flow equalizer. In an etching process, the processing gases may be unevenly drawn from the processing chamber which may cause an uneven etching of the substrate. The integrated flow equalizer is configured to equalize the flow of the processing gases evacuated from the chamber via the lower liner.