Process Chamber Exhaust Liner Layout for Uniform Gas Flow
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Solution Overview
Problem
Conventional process chambers with a single pump for exhausting process gases lead to non-uniform gas flow and subsequent processing non-uniformities in semiconductor substrates, exacerbated by shrinking critical dimensions requiring more uniform processing.
Innovation Solution
The implementation of an exhaust liner system with a lower and upper annular body, multiple exhaust holes, and strategically defined plenums to create a uniform gas flow path, reducing skew in velocity profiles and enhancing uniformity across the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pump is used to exhaust process gases from one side of the process chamber, then the exhaust system is simple and cost-effective, but non-uniform gas flow is caused leading to process non-uniformities on the substrate
Solution Approach 1:
The exhaust system is segmented into multiple independent exhaust ports (first exhaust port and second exhaust port) positioned at different locations on the process chamber. This segmentation allows gas to be exhausted from multiple zones simultaneously, creating more uniform gas flow patterns across the substrate surface and eliminating the process non-uniformities caused by single-side exhaust.
Solution Approach 2:
Different regions of the process chamber are equipped with exhaust ports having different characteristics (positions, sizes, or flow capacities) to match the local gas flow requirements. The first exhaust port is positioned to handle gas flow from one region while the second exhaust port handles another region, ensuring uniform exhaust across the entire substrate area.
2Productivity
If critical dimensions for semiconductor devices are reduced to increase device density, then more devices can be integrated, but process non-uniformities are exacerbated requiring more uniform processing
Solution Approach 1:
The exhaust system is divided into multiple exhaust ports positioned at different locations on the process chamber. This segmentation creates multiple gas flow pathways that work together to maintain uniform gas distribution across the substrate, which is critical for achieving uniform processing results when manufacturing features at reduced critical dimensions.
Solution Approach 2:
The exhaust system transitions from a single-point exhaust to a distributed multi-point exhaust arrangement. By adding the spatial dimension of multiple exhaust locations around the chamber, the system achieves more uniform gas flow patterns and pressure distribution, enabling consistent processing across the entire substrate area even as critical dimensions shrink.
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
This solution improves process uniformity by ensuring a consistent gas flow distribution across the substrate, addressing the issue of non-uniform etch rates and on-substrate processing results, and facilitating better chamber matching in multi-chamber systems.
Implementation Method 1
defining a gas flow path from the central opening to the first plenum via the plurality of exhaust holes and from the first plenum to the second plenum via the at least one cutout
Data Source
AI summary
Embodiments of exhaust liner systems are provided herein. In some embodiments, an exhaust liner system for use in a process chamber includes a lower exhaust liner having an annular body with a central opening; an upper flange, a central flange, and a lower flange extending outward from the annular body, wherein the lower flange and the central flange partially define a first plenum, and wherein the central flange and the upper flange partially define a second plenum; a plurality of exhaust holes from the central opening to the first plenum; and at least one cutout in the central flange to provide a flow path from the first plenum to the second plenum, wherein the lower exhaust liner defines a gas flow path from the central opening to the first plenum via the plurality of exhaust holes and from the first plenum to the second plenum via the least one cutout.