Semiconductor Cleaning Composition for Residue Removal and Metal Protection
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Solution Overview
Problem
Current cleaning compositions for semiconductor substrates are ineffective in removing plasma ash residues without corroding or dulling metal circuitry, particularly challenging with metals like copper and cobalt, and often require high organic content, which can affect electrical resistance and device integrity.
Innovation Solution
Aqueous-based cleaning composition comprising 55-80% water, 0.3-5% EDTA, 10-30% amine compound, 0.1-5% polyfunctional organic acid, 0.01-8% fluoride ion source, and 0-60% water-miscible organic solvent, optionally with a corrosion inhibitor, designed to remove residues while protecting metals and maintaining critical dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning compositions are used to remove plasma ash residues, then cleaning effectiveness is improved, but metal circuitry (copper and cobalt) is corroded or dulled
Solution Approach 1:
The invention changes the chemical parameters of the cleaning composition by using a water-miscible organic solvent system with controlled pH (2-10) and specific solvent ratios (e.g., 1:1 water:IPA or 1:4 water:acetone). This parameter optimization enables effective removal of plasma ash residues while maintaining low metal etch rates (≤4 Å/min) and preventing corrosion of copper and cobalt circuitry.
Solution Approach 2:
The cleaning composition employs a composite solvent system combining water-miscible organic solvents (such as isopropyl alcohol, acetone, or methanol) with water and optional surfactants. This composite formulation synergistically enhances cleaning effectiveness for organic and inorganic residues while the water-miscible nature ensures rapid evaporation and minimal metal attack, resolving the contradiction between cleaning power and metal protection.
2Reliability
If high organic content cleaning compositions are used, then residue removal capability is improved, but electrical resistance increases and device integrity is compromised
Solution Approach 1:
The invention optimizes the organic solvent content parameter to balance cleaning effectiveness with electrical performance. By controlling the organic solvent concentration and selecting water-miscible solvents with appropriate evaporation rates, the composition achieves thorough residue removal while minimizing residual organic film formation that could increase electrical resistance. The pH parameter (2-10 range) is also optimized to prevent metal corrosion that would otherwise increase resistance.
Solution Approach 2:
The invention replaces aggressive organic-based cleaning mechanisms with a water-miscible solvent system that relies on controlled chemistry rather than high organic concentration. This substitution reduces the harmful side effects of high organic content (such as resistance increase and device contamination) while maintaining effective cleaning through optimized solvent-water interactions and pH control.
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 composition effectively removes photoresist and plasma ash residues from semiconductor substrates with low metal etch rates (≤4 Å/min) and corrosion protection for copper and cobalt, ensuring efficient cleaning without altering metal structures or increasing electrical resistance.
Implementation Method 1
the etching agent may be hydrofluoric acid
Implementation Method 2
the exposed or unexposed photoresist material, depending on its composition, is typically dissolved with developers
Implementation Method 3
from about 0 to about 60% by weight of a water-miscible organic solvent
Data Source
AI summary
A composition useful for removing residue from a semiconductor substrate comprising in effective cleaning amounts: from about 55 to 80% by weight of water; from about 0.3 to about 5.0% by weight of EDTA; from about 10.0 to about 30.0% by weight of an amine compound wherein the amine compound is selected from the group consisting of a secondary amine, a tertiary amine, and mixtures thereof; from about 0.1 to about 5.0% by weight of a polyfunctional organic acid; from about 0.01 to about 8.0% by weight of a fluoride ion source; from about 0 to about 60% by weight of a water-miscible organic solvent; and from about 0 to about 15% by weight of a corrosion inhibitor.