Dual-Plenum Showerhead Structure for Uniform Gas Distribution
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Solution Overview
Problem
Existing substrate processing systems face challenges in efficiently distributing process gases and preventing jetting and back diffusion, particularly when reducing the gap between the showerhead and the substrate.
Innovation Solution
A dual-plenum showerhead design with a base portion and a backplate, featuring a first and second plenum, and a baffle plate with increasing diameter through holes to uniformly distribute process gases, along with an adapter for cooling and optimizing gas flow rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the gap between the showerhead and substrate is reduced to improve process uniformity, then manufacturing precision is improved, but jetting and back diffusion occur causing harmful effects
Solution Approach 1:
The showerhead is divided into two separate plenums (first plenum and second plenum) that are isolated from each other by a partition. This segmentation allows independent control of gas flow in each plenum, preventing jetting and back diffusion while maintaining a reduced gap between the showerhead and substrate for improved process uniformity.
Solution Approach 2:
A partition acts as an intermediary structure between the first and second plenums, physically separating the gas flows to prevent harmful interactions such as jetting and back diffusion, while still allowing the overall showerhead design to maintain close proximity to the substrate.
2Device complexity
If a single plenum design is used to simplify the structure, then device complexity is reduced, but gas distribution uniformity deteriorates
Solution Approach 1:
The single plenum is segmented into two separate plenums with independent gas distribution systems. This segmentation enables tailored gas flow control in different regions, improving overall gas distribution uniformity while the modular design keeps the structural complexity manageable.
Solution Approach 2:
Each plenum is designed with locally optimized features including varying orifice sizes and distributions tailored to specific regional requirements. The first plenum has orifices configured for one gas flow pattern while the second plenum has orifices configured for a different gas flow pattern, achieving superior overall uniformity.
Data Source
AI summary
A dual-plenum showerhead for a substrate processing system comprises a base portion and a backplate. The base portion comprises a first surface facing a substrate, a second surface opposite the first surface, and a sidewall extending between the first surface and the second surface. The first and second surfaces are flat. The first and second surfaces and the sidewall define a first plenum. The backplate comprises a shaped surface extending from a center portion of the backplate to a periphery of the backplate. The shaped surface comprises a plurality of portions. At least one of the portions is parallel to the base portion. At least one of the portions slopes towards the base portion. The periphery of the backplate is attached to the second surface of the base portion defining a second plenum.