Dual-Zone Gas Distribution Assembly for CVD Flow Isolation
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Solution Overview
Problem
Conventional semiconductor processing systems face challenges in delivering multiple gases to a processing region without premature mixing, leading to unwanted reactions and particle formation within the chamber components, which reduces process efficiency and increases downtime for cleaning.
Innovation Solution
A dual zone gas distribution assembly with separate manifolds and apertures for each gas, ensuring they remain isolated until just before reaching the substrate, along with thermal control features to manage reactivity, prevents premature mixing and deposition on chamber components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If gases are mixed in a mixing chamber before delivery to the processing region, then uniform distribution of component gases is achieved, but unwanted reactions and deposition occur within the mixing chamber and distribution components
Solution Approach 1:
The gas distribution assembly is segmented into multiple independent flow paths, with each process gas delivered through separate channels and apertures in the distribution plate, preventing premature mixing and reactions within the distribution components while maintaining uniform distribution at the substrate level
Solution Approach 2:
The mixing function is extracted from the distribution assembly by delivering gases separately through independent manifolds and apertures, removing the harmful mixing process from the distribution components while preserving the beneficial uniform distribution effect at the point of contact with the substrate
2Object-generated harmful factors
If gases are delivered separately through independent channels, then unwanted reactions in chamber components are minimized, but uniform distribution of component gases becomes more difficult to achieve
Solution Approach 1:
The distribution plate incorporates locally optimized aperture patterns and flow path geometries that ensure uniform gas distribution across the substrate surface, while the upstream portions of the system maintain separate gas channels to prevent unwanted reactions in the chamber components
3Device complexity
If a conventional mixing chamber is used to combine multiple gases, then gas delivery is simplified, but reaction by-products accumulate in the chamber components creating particles
Solution Approach 1:
The gas delivery system is segmented into separate manifolds and flow paths for each process gas, with individual apertures in the distribution plate for each gas type, eliminating the mixing chamber while maintaining controlled delivery to the substrate
Solution Approach 2:
The harmful mixing and reaction process is extracted from the gas delivery system by delivering gases separately through independent channels until the moment of contact with the substrate, removing the source of particle-forming reaction by-products from the chamber components
4Productivity
If gases are heated to promote chemical reactions, then deposition efficiency is improved, but premature reactions occur in the gas delivery components
Solution Approach 1:
The heated processing region is segmented from the gas delivery components by maintaining separate, isolated flow paths for each gas, allowing the substrate and immediate processing zone to be heated for efficient deposition while keeping the upstream gas channels cool to prevent premature reactions
Data Source
AI summary
Apparatus and methods for gas distribution assemblies are provided. In one aspect, a gas distribution assembly is provided comprising an annular body comprising an annular ring having an inner annular wall, an outer wall, an upper surface, and a bottom surface, an upper recess formed into the upper surface, and a seat formed into the inner annular wall, an upper plate positioned in the upper recess, comprising a disk-shaped body having a plurality of first apertures formed therethrough, and a bottom plate positioned on the seat, comprising a disk-shaped body having a plurality of second apertures formed therethrough which align with the first apertures, and a plurality of third apertures formed between the second apertures and through the bottom plate, the bottom plate sealingly coupled to the upper plate to fluidly isolate the plurality of first and second apertures from the plurality of third apertures.