Blocker Plate Bypass for CVD Gas Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor substrate processing systems face inefficiencies in chamber cleaning due to the common feed path for both processing and cleaning gases, leading to reduced cleaning efficiency, increased time, and lower substrate throughput, especially when operating at reduced flow rates.
Innovation Solution
A gas distribution system with a blocker plate and gas distribution plate that allows independent control of processing and cleaning gas pathways, enabling cleaning gases to bypass the blocker plate and be directed to both the center and perimeter of the chamber, improving cleaning efficiency and uniformity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If cleaning gases are passed through the common feed path adapted for reduced flow, then the system maintains simple gas distribution structure, but cleaning efficiency is significantly reduced
Solution Approach 1:
The gas distribution system is segmented into separate feed paths: a common feed path for process gases and a dedicated bypass path for cleaning gases. This segmentation allows each gas type to have optimized flow control, enabling high-flow cleaning operations without compromising the simple overall structure.
Solution Approach 2:
The bypass path acts as an intermediary channel that allows cleaning gases to circumvent the blocker plate and common feed path restrictions. This intermediary structure enables cleaning gases to reach the chamber with sufficient flow rate while maintaining the simplicity of the primary gas distribution system.
2Productivity
If all cleaning gases are directed to the periphery of the gas distribution plate, then cleaning rate at the perimeter is increased, but the center of the chamber is not sufficiently cleaned
Solution Approach 1:
The gas distribution plate is designed with non-uniform aperture distribution, where the density and size of holes vary across different regions. This local quality variation enables preferential directing of cleaning gases to the periphery while still providing adequate coverage to the center, achieving both high perimeter cleaning rate and sufficient center cleaning.
Solution Approach 2:
The solution addresses the two-dimensional cleaning uniformity problem by utilizing the third dimension of aperture geometry (hole size and density variation) across the plate surface. This dimensional approach allows differential gas flow distribution to different chamber regions simultaneously.
3Device complexity
If cleaning gases are passed through the common feed path, then the system structure remains simple, but the time required for cleaning increases
Solution Approach 1:
The feed path system is segmented into two independent channels: the common feed path for process gases and a bypass path for cleaning gases. This segmentation allows cleaning operations to proceed at optimized high flow rates through the bypass, reducing cleaning time while maintaining structural simplicity through the integrated design.
4Device complexity
If the common feed path is used for both process and cleaning gases, then device complexity is reduced, but substrate throughput is reduced
Solution Approach 1:
The gas distribution system is segmented into independent feed paths for process and cleaning operations. This allows parallel or rapid sequential operations without cross-contamination or flow interference, increasing substrate throughput while maintaining overall system simplicity through modular integration.
Solution Approach 2:
The bypass path enables continuous, uninterrupted flow of cleaning gases at optimal rates, allowing cleaning operations to proceed without the flow restrictions that would otherwise limit throughput. This continuous efficient action maximizes productivity while the integrated design keeps complexity low.
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 significantly enhances cleaning efficiency, increasing etch rates and uniformity across the chamber, reducing the time required for cleaning, and improving substrate processing capacity by allowing independent control of cleaning gas distribution.
Implementation Method 1
a remote plasma cleaning procedure may be employed using an etchant plasma generated remotely from the deposition chamber by introduction of an etchant gas such as a fluorine containing gas to a remote high density plasma source
Implementation Method 2
Dissociated species from the etchant plasma transported to the deposition chamber react with and etch away the undesired deposition buildup
Implementation Method 3
A gas distribution plate or faceplate of the deposition chamber includes a plurality of spaced holes that process gases pass through to aid in distributing the materials in the chamber
Implementation Method 4
A bypass gas pathway delivers a second gas through the plurality of feed through passageways in the blocker plate and to areas around the blocker plate prior to the second gas passing through the gas distribution plate
Data Source
AI summary
Apparatus and methods for distributing gases into a processing chamber are disclosed. In one embodiment, the apparatus includes a gas distribution plate having a plurality of apertures disposed therethrough and a blocker plate having both a plurality of apertures disposed therethrough and a plurality of feed through passageways disposed therein. A first gas pathway delivers a first gas through the plurality of apertures in the blocker plate and the gas distribution plate. A bypass gas pathway delivers a second gas through the plurality of feed through passageways in the blocker plate and to areas around the blocker plate prior to the second gas passing through the gas distribution plate.