Cover Wafer Design Mitigates Halogen Contaminant Build-Up
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Solution Overview
Problem
Conventional semiconductor processing systems face challenges in maintaining uniformity and preventing contaminant build-up, particularly due to halogen-based deposits on substrate supports, which can lead to non-uniform film deposition and reduced component lifespan.
Innovation Solution
The introduction of a cover plate with specific design features, such as a flange and protrusions, that limits contact with the substrate support and includes an aperture, reduces the impact of halogen-containing plasma effluents during cleaning, thereby mitigating contaminant build-up and improving process uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If cleaning operations are performed to remove production materials, then material removal is achieved, but halogen-based contaminant build-up occurs on substrate supports
Solution Approach 1:
The patent extracts and removes the shadow ring component from the processing chamber after substrate removal. This extracted shadow ring is then used as a dedicated cleaning target outside the chamber, preventing halogen-based contaminants from depositing on the substrate support platen during cleaning operations. The harmful cleaning byproducts are effectively transferred to the removed shadow ring.
Solution Approach 2:
The shadow ring serves as an intermediary component that absorbs halogen-based contaminants during cleaning operations. By positioning the shadow ring to contact the platen and then removing it, the cleaning effluents are intercepted by the shadow ring rather than directly contaminating the substrate support, thus protecting the platen from harmful deposits.
2Ease of operation
If shadow ring contacts the substrate support during engagement, then shadow ring function is achieved, but contaminant build-up on substrate support increases
Solution Approach 1:
The patent implements a dynamic engagement system where the shadow ring can be positioned to contact the platen during substrate loading/unloading operations, then removed afterward. The protrusions on the platen provide dynamic contact points that enable easy engagement while the subsequent removal prevents contaminant transfer to the substrate support, resolving the contradiction between operational ease and contamination prevention.
3Reliability
If cleaning effluents are used to remove residual materials, then cleaning effectiveness is improved, but halogen-based deposits are created on exposed surfaces
Solution Approach 1:
The patent converts the harmful effect of halogen-based cleaning effluents into a beneficial process by directing these effluents onto the shadow ring instead of the substrate support platen. The shadow ring acts as a sacrificial target that absorbs the harmful deposits, while the platen remains clean and ready for the next substrate processing cycle.
Data Source
AI summary
Semiconductor processing systems according to embodiments of the present technology may include a chamber body having sidewalls and a base. The chamber body may define an internal volume. The systems may include a substrate support assembly having a shaft and a platen coupled with the shaft along a first surface of the platen. The semiconductor processing systems may include a cover plate positioned on the platen of the substrate support assembly along a second surface of the platen opposite the first surface. The cover plate may include a flange extending about an exterior region of the cover plate. The flange may be in direct contact with the platen. The cover plate may include an upper wall vertically offset from the flange. An interior volume may be defined between the upper wall and the platen of the substrate support assembly.