Substrate Wet Etching With Conductivity-Controlled Byproduct Removal
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Solution Overview
Problem
The wet etching process in semiconductor manufacturing often results in process by-products being re-deposited on the substrate, especially when the etchant is recycled, which affects the efficiency and quality of the substrate processing.
Innovation Solution
A substrate processing method and apparatus that involves supplying an etchant to remove films on substrates, followed by a removal liquid with conductivity in a set range to effectively remove impurities and by-products electrostatically attached to the substrate, thereby improving the efficiency of the film removal process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If the etchant is recycled to reduce waste, then resource efficiency is improved, but process by-products are re-deposited on the substrate
Solution Approach 1:
The liquid supply system is segmented into multiple independent nozzles (first liquid supply nozzle, second liquid supply nozzle, third liquid supply nozzle) that can deliver different liquids (etchant, wetting liquid, removal liquid) separately and sequentially to the substrate, enabling precise control over the processing stages
Solution Approach 2:
The wetting liquid is supplied to the substrate before the etchant to prepare the substrate surface, and the removal liquid is supplied after the etchant to clean the substrate. These preliminary and follow-up actions prevent the harmful re-deposition effect while allowing etchant recycling
2Productivity
If the wet etching process is performed to remove films on substrate, then film removal efficiency is improved, but process by-products are generated and re-deposited
Solution Approach 1:
The removal liquid acts as an intermediary substance that is supplied after the etching process to remove process by-products from the substrate. This intermediary cleaning step eliminates the harmful re-deposition effect while preserving the high film removal efficiency of the wet etching process
Solution Approach 2:
The conductivity of the removal liquid is controlled within a specific range (5 to 40 μS/cm) to optimize its ability to remove electrostatically attached process by-products. This parameter control ensures effective by-product removal without causing new issues
3Object-generated harmful factors
If removal liquid with high conductivity is used to remove impurities, then impurity removal effectiveness is improved, but substrate quality may be compromised
Solution Approach 1:
The conductivity of the removal liquid is precisely controlled within the range of 5 to 40 μS/cm. This optimized conductivity level is sufficient to remove electrostatically attached process by-products through electrostatic discharge while maintaining substrate quality and preventing damage to the substrate or deposited films
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
The proposed method and apparatus enhance the efficiency of substrate processing by effectively removing films and process by-products, improving the quality of the substrate and reducing re-deposition issues associated with recycled etchants.
Implementation Method 1
the impurities are attached to the metal surface by static electricity, and the removal liquid has conductivity in a set range to remove the static electricity and separate the impurities from the metal surface
Data Source
AI summary
Disclosed is a method of processing a substrate, the method including: an etchant supply operation of supplying an etchant to remove a film on a substrate; and a removal liquid supply operation of supplying a removal liquid to remove impurities attached onto the substrate, after the etchant supply operation is performed, in which the removal liquid has conductivity in a set range.