Water-Insoluble Surfactant Film Prevents Wafer Pattern Collapse
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Solution Overview
Problem
The challenge in semiconductor device production is pattern collapse during cleaning, particularly for wafers with finely uneven patterns containing metal-based materials, where existing water-repellent protecting films cannot be effectively formed, leading to capillary force-induced pattern collapse.
Innovation Solution
A liquid chemical with a water-insoluble surfactant that forms a water-repellent protecting film on the wafer surface, using a surfactant with a hydrophobic moiety and a functional moiety that adsorbs to metal-based materials via Van der Waals or covalent bonds, reducing capillary force and preventing pattern collapse.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing water-repellent protecting films are used on wafers with metal-based materials, then the film formation is insufficient, but using alternative materials or methods increases process complexity
Solution Approach 1:
The patent changes the chemical composition parameters of the protecting film by incorporating specific surfactants with hydrophobic moieties and metal-coordinating functional groups. This modifies the film's interaction with metal-based materials, enabling effective protecting film formation on wafers containing titanium, tungsten, aluminum, copper, tin, tantalum nitride, or ruthenium without requiring complex process changes
Solution Approach 2:
The protecting film is designed as a composite structure combining hydrophobic surfactant molecules that coordinate with metal-based materials. This composite approach integrates both water-repellent properties and metal-specific adhesion, resolving the contradiction between film effectiveness and process simplicity
2Manufacturing precision
If cleaning liquid is used to remove contaminants, then cleaning effectiveness is achieved, but capillary force causes pattern collapse in high aspect ratio structures
Solution Approach 1:
The patent applies a protecting film to the wafer surface before the cleaning step. This preliminary action creates a water-repellent barrier that prevents capillary force from acting on the pattern structures during subsequent cleaning and drying operations, thereby preventing pattern collapse while maintaining cleaning effectiveness
Solution Approach 2:
The protecting film provides preliminary anti-action against capillary force by creating a hydrophobic surface that repels cleaning liquids. This counteracts the harmful capillary forces before they can cause pattern collapse, allowing effective cleaning without compromising pattern integrity
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 solution effectively reduces capillary force on the wafer surface, preventing pattern collapse and improving the cleaning process for semiconductor devices with finely uneven patterns, enhancing production yield and productivity without modifying conventional equipment.
Implementation Method 1
a functional moiety that adsorbs to metal-based materials
Implementation Method 2
adsorbs to metal-based materials via Van der Waals or covalent bonds
Implementation Method 3
adsorbs to metal-based materials via Van der Waals or covalent bonds
Implementation Method 4
reducing capillary force and preventing pattern collapse
Data Source
AI summary
Disclosed is a liquid chemical for forming a water-repellent protecting film on a wafer. The liquid chemical is a liquid chemical containing a water-repellent-protecting-film-forming agent for forming the water-repellent protecting film, at the time of cleaning the wafer which has a finely uneven pattern at its surface and contains at least at a part of a surface of a recessed portion of the uneven pattern at least one kind of matter selected from the group consisting of titanium, titanium nitride, tungsten, aluminum, copper, tin, tantalum nitride, ruthenium and silicon, at least on the surface of the recessed portion. The liquid chemical is characterized in that the water-repellent-protecting-film-forming agent is a water-insoluble surfactant. The water-repellent protecting film formed with the liquid chemical is capable of preventing a pattern collapse of the wafer, in a cleaning step.