Cleaning Liquid for Fluorocarbon Removal in Semiconductor Etching
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Solution Overview
Problem
In semiconductor manufacturing, there is a need for a cleaning liquid that can effectively remove fluorocarbon layers and resist films without phase separation during storage, particularly in the BOSCH etching method, where fluorocarbon layers adhere to silicon substrates and are difficult to remove.
Innovation Solution
A cleaning liquid comprising 3-alkoxy-3-methyl-1-butanol, a specific monomethyl ether compound, and quaternary ammonium hydroxide is used, which effectively removes fluorocarbon layers, resist films, and polyimide layers while preventing phase separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cleaning liquid is used to remove fluorocarbon layers deposited by BOSCH etching, then the fluorocarbon layer can be removed, but the cleaning liquid undergoes phase separation during storage
Solution Approach 1:
The patent modifies the chemical composition parameters of the cleaning liquid by selecting specific solvents (cyclic carbonate esters like EC and PC, and chain carbonate esters like DMC) with carefully controlled boiling points and chemical properties. This parameter optimization allows the cleaning liquid to maintain phase stability during storage while retaining effective removal capability for fluorocarbon layers and resist films
Solution Approach 2:
The invention creates a composite cleaning liquid system by combining multiple components: cyclic carbonate esters (EC, PC), chain carbonate esters (DMC), and quaternary ammonium hydroxide. This composite formulation synergistically achieves both storage stability and effective removal performance, resolving the contradiction between stability and effectiveness
2Reliability
If a cleaning liquid contains strong solvents to remove crosslinking type negative resist films, then the resist film can be removed, but phase separation occurs during storage
Solution Approach 1:
The patent optimizes solvent parameters by selecting cyclic carbonate esters (EC with bp 90°C, PC with bp 160°C) and chain carbonate esters (DMC with bp 90°C) that have appropriate boiling points and chemical properties. This parameter selection enables the cleaning liquid to dissolve crosslinked resist films effectively while preventing phase separation during storage
Solution Approach 2:
The cleaning liquid acts as an intermediary medium that bridges the conflicting requirements of strong solvent power and storage stability. The specific combination of cyclic and chain carbonate esters with quaternary ammonium hydroxide creates a stable intermediate system that can remove crosslinked resist films without undergoing phase separation
3Manufacturing precision
If fluorocarbon gas is used during BOSCH etching to form protective layers, then etching precision is improved, but the fluorocarbon layer becomes difficult to remove
Solution Approach 1:
The patent converts the harmful effect of strong fluorocarbon layer adhesion into a beneficial removal mechanism. The cleaning liquid formulation, containing cyclic carbonate esters, chain carbonate esters, and quaternary ammonium hydroxide, specifically targets and effectively removes the strongly adhering fluorocarbon layers deposited during BOSCH etching, transforming the removal difficulty into a solvable challenge
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 cleaning liquid efficiently removes targeted layers without phase separation, ensuring effective substrate etching and processing in semiconductor manufacturing, maintaining storage stability and enhancing etching precision.
Implementation Method 1
a cleaning liquid includes (A1) 3-alkoxy-3-methyl-1-butanol represented by the following general formula (1), (A2) at least one monomethyl ether compound selected from the group consisting of diethylene glycol monomethyl ether and triethylene glycol monomethyl ether, and (B) quaternary ammonium hydroxide
Implementation Method 2
the cleaning liquid efficiently removes targeted layers without phase separation, ensuring effective substrate etching and processing
Data Source
AI summary
A cleaning liquid which includes 3-alkoxy-3-methyl-1-butanol represented by the following general formula (1); at least one of diethylene glycol monomethyl ether and triethylene glycol monomethyl ether; and quaternary ammonium hydroxide:in which R1 represents an alkyl group having 1 to 5 carbon atoms.