Patterned Si Substrate Cleaning With Delayed IPA Mixing
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Solution Overview
Problem
Existing substrate cleaning processes for patterned Si films generate particles due to the removal of oxides, which can lead to defects in semiconductor devices.
Innovation Solution
A substrate processing method that involves using a cleaning liquid containing hydrofluoric acid and water, while rotating the substrate, and mixing an organic solvent with lower surface tension than water into the cleaning liquid to suppress particle generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cleaning liquid containing hydrofluoric acid and water is used to remove oxide from the substrate, then the oxide removal effectiveness is improved, but particle generation occurs during the cleaning process
Solution Approach 1:
The patent changes the surface tension parameter of the cleaning liquid by adding organic solvent (IPA) to reduce it from water's high surface tension to a lower value. This parameter change allows the cleaning liquid to better wet the substrate surface and remove particles without compromising oxide removal effectiveness, thus resolving the contradiction between reliable oxide removal and particle generation suppression
2Manufacturing precision
If the substrate is rotated during cleaning process, then the cleaning uniformity is improved, but particle generation is exacerbated
Solution Approach 1:
The patent creates a composite cleaning liquid by mixing hydrofluoric acid, water, and organic solvent (IPA). This composite liquid combines the oxide removal capability of HF with the low surface tension property of IPA, enabling both uniform cleaning during rotation and particle suppression through reduced surface tension that prevents particle adhesion
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 method effectively suppresses particle generation during the cleaning of substrates with patterned Si films, ensuring higher cleanliness and reducing defects in semiconductor devices.
Implementation Method 1
mixing an organic solvent, which has miscibility with the water and has a lower surface tension than the water, into the cleaning liquid
Data Source
AI summary
A substrate processing method of cleaning a substrate having a patterned Si film while removing an oxide on the Si film includes removing the oxide by supplying a cleaning liquid containing hydrofluoric acid and water to the substrate while rotating the substrate; and mixing an organic solvent, which has miscibility with the water and has a lower surface tension than the water, into the cleaning liquid. The mixing of the organic solvent is performed during the removing of the oxide and after a predetermined time has elapsed from a start of the removing of the oxide.