Gas-Flow Adjusting Mechanism for Uniform Substrate Etching
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Solution Overview
Problem
Conventional etching apparatuses face challenges in achieving uniform etching across the entire surface and depth of semiconductor substrates, particularly with polysilicon and bulk silicon, due to non-uniform etching gas flow and high etching performance variations, leading to inconsistent etching depths and adverse effects on semiconductor characteristics.
Innovation Solution
An etching apparatus with a gas-flow adjusting mechanism that controls the etching gas flow from the periphery to the center of the substrate, using a concentric circular arrangement with vertically movable components to ensure uniform gas distribution and reduce etching area gradually, combined with a buffer chamber for uniform gas composition and temperature control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional etching apparatus is used with high etching performance gas, then etching speed is improved, but etching depth uniformity across substrate surface deteriorates
Solution Approach 1:
The gas flow control mechanism creates location-specific flow patterns that ensure uniform gas distribution across the substrate surface. Gas flows from the periphery toward the center, providing consistent etching conditions across different regions, thereby achieving both high etching speed and uniform etching depth across the entire substrate surface
Solution Approach 2:
The invention introduces a dynamic gas flow control system that actively manages gas distribution across the substrate. The gas flow direction and velocity are controlled to move from periphery to center, creating dynamic conditions that maintain uniform etching depth while preserving high etching speed throughout the process
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 enables uniform etching across the substrate surface and depth, reducing etching variations and maintaining high etching performance, even with ozone-containing gases, thereby ensuring accurate and efficient evaluation of semiconductor substrate characteristics.
Implementation Method 1
a gas-flow adjusting means that is arranged on a substantially concentric circle above the substrate and allows the etching gas to flow in a direction from a periphery of the substrate to substantially the center of the substrate
Implementation Method 2
A vapor-phase decomposition method using etching gas generated by bubbling a mixed acid solution formed of nitric acid or hydrogen peroxide mixed with a hydrofluoric acid or the like is known as etching of a constitutional film of a substrate
Data Source
AI summary
The present invention provides an etching apparatus suitable for etching polysilicon on a substrate or bulk silicon constituting the substrate. The present invention relates to an etching apparatus including a gas-flow adjusting means that allows etching gas to flow from a periphery of a substrate to substantially a center of the substrate, and relates to a technology capable of etching polysilicon or bulk silicon at a uniform thickness on an entire substrate surface. In addition, the gas-flow adjusting means is installed in a vertically movable manner, and an etching speed can be controlled by an adjustment of the gas-flow adjusting means.