Anhydrous Substrate Cleaning via Supercritical CO2 Drying
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional substrate cleaning processes using organic solvents like IPA for drying semiconductor substrates with fine circuit patterns can lead to pattern collapse due to low surface tension and the presence of water, which affects cleaning efficiency and yield.
Innovation Solution
An anhydrous substrate cleaning composition comprising an etching compound like ammonium fluoride, a solvent such as acetic anhydride, and a phase change assistant material like isopropyl alcohol, used in conjunction with a supercritical fluid like CO2, to prevent pattern collapse and enhance cleaning efficiency without water.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If an organic solvent like IPA is used for drying the substrate, then the drying process can be completed, but pattern collapse occurs due to low surface tension
Solution Approach 1:
The patent changes the surface tension parameter of the drying fluid by using CO2 supercritical fluid instead of organic solvents like IPA. The supercritical fluid has adjustable surface tension properties through pressure and temperature control, allowing effective drying without the pattern collapse caused by low surface tension solvents.
Solution Approach 2:
The patent utilizes the phase transition characteristics of CO2 between supercritical and gaseous states. By controlling pressure and temperature, the CO2 transitions to a supercritical state for cleaning/drying, then returns to gaseous state for easy removal, avoiding residual effects that cause pattern collapse.
2Productivity
If water is present in the cleaning composition, then cleaning efficiency can be maintained, but water-related issues affect the substrate
Solution Approach 1:
The patent extracts and removes water from the cleaning composition entirely, using anhydrous conditions with CO2 supercritical fluid as the cleaning medium. This eliminates water-related harmful effects while maintaining cleaning effectiveness through the unique properties of supercritical CO2.
Solution Approach 2:
The patent creates an inert, water-free environment using CO2 supercritical fluid. The inert nature of CO2 prevents water-related chemical reactions and contamination, while still providing effective cleaning capability for semiconductor substrates.
3Productivity
If conventional cleaning processes are used, then foreign substances can be removed, but the process complexity increases with multiple steps
Solution Approach 1:
The patent merges multiple cleaning and drying functions into a single integrated process using CO2 supercritical fluid. The supercritical fluid simultaneously performs cleaning, drying, and displacement of water, eliminating the need for separate cleaning and drying steps.
Solution Approach 2:
The CO2 supercritical fluid serves multiple functions: it acts as a cleaning agent for removing foreign substances, a drying agent for removing water, and a displacement medium. This multi-functionality simplifies the overall process while maintaining effective foreign substance removal.
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 anhydrous composition effectively cleans semiconductor substrates without causing pattern collapse, improving cleaning efficiency and reducing the risk of water-related issues, while using a binder like isopropoxy ethanol prevents particle re-attachment.
Implementation Method 1
cleaning the substrate by supplying a supercritical fluid to the substrate
Implementation Method 2
a phase change assistant material that improves a solubility of a supercritical fluid
Data Source
AI summary
Disclosed are an anhydrous substrate cleaning composition, a substrate treating method, and a substrate treating apparatus. The substrate cleaning composite includes an etching compound that provides a component for treating a substrate, and a solvent that dissolves the etching compound, wherein the substrate cleaning composite is an anhydrous composite that does not include water.