Multi-Zone Gas Supply for Etching Uniformity
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Solution Overview
Problem
Conventional etching processes for silicon-containing films, such as SiGe films, face challenges in achieving uniformity due to inadequate control over the flow and flow rate of treatment gases in multi-wafer treatment apparatuses, leading to inconsistencies in etching results.
Innovation Solution
The etching apparatus features a gas supply system with a central region and an outer peripheral region, each capable of independently controlling the flow rate of treatment gases, ensuring uniform distribution across the substrate surface by dividing the diffusion space and using separate shower plates and diffusion plates for central and peripheral areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single gas supply system is used for the entire substrate surface, then the device complexity is reduced, but the manufacturing precision of etching uniformity deteriorates
Solution Approach 1:
The gas supply system is divided into a central region gas supply and an outer peripheral region gas supply, with separate flow rate control for each region. This segmentation allows independent optimization of gas flow distribution across different areas of the substrate, resolving the contradiction by increasing functional complexity only where needed to achieve uniform etching results.
Solution Approach 2:
Different gas flow rates are applied to different regions of the substrate based on local requirements. The central region and outer peripheral region have distinct flow rate characteristics optimized for their specific etching needs, enabling precise control of etching uniformity without requiring complete system redesign.
2Productivity
If the treatment gas flow rate is increased to improve etching speed, then the productivity increases, but the manufacturing precision of etching uniformity deteriorates due to inadequate flow control
Solution Approach 1:
The gas supply system incorporates independent and adjustable flow rate control for both central and outer peripheral regions, allowing dynamic optimization of gas flow characteristics. This enables the system to maintain high productivity through increased overall flow while preserving uniformity through region-specific flow rate adjustment, resolving the contradiction between speed and precision.
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 configuration enables uniform etching of silicon-containing films by optimizing the flow rates of gases in the central and peripheral regions, enhancing in-plane uniformity and improving etching results by adjusting the flow speed and residence time of the treatment gas.
Implementation Method 1
a gas supply configured to supply a treatment gas from an upper space above the stage toward the stage
Implementation Method 2
a gas exhauster configured to evacuate an interior of the treatment container
Data Source
AI summary
A substrate etching apparatus for etching a substrate, the substrate etching apparatus includes a treatment container configured to accommodate a substrate, a stage on which the substrate is placed, the stage being disposed in the treatment container, a gas supply configured to supply a treatment gas from an upper space above the stage toward the stage, and a gas exhauster configured to evacuate an interior of the treatment container. The gas supply includes a central region facing a central part of the stage and an outer peripheral region having a same central axis as the central region and configured to surround the central region. The gas supply is capable of supplying the treatment gas to each of the central region and the outer peripheral region.