Post CMP Cleaning Composition for Copper and Cobalt Surfaces
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Solution Overview
Problem
Current methods for cleaning microelectronic devices struggle to effectively remove residues and contaminants, particularly from copper and cobalt surfaces, which can lead to poor electrical performance and device failure due to roughening and corrosion, especially with the use of tantalum and tantalum nitride barrier layers in advanced technology nodes.
Innovation Solution
A cleaning composition comprising etchant materials like amines and complexing agents, cleaning additives such as ethylene oxide/propylene oxide block copolymers, corrosion inhibitors, and pH adjusters, which is compatible with copper, low-k dielectric materials, and barrier materials like tantalum-containing materials, is used to remove post-CMP, post-etch, and post-ash residues, ensuring the surface is substantially devoid of contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning methods are used on copper surfaces, then cleaning action is achieved, but corrosion and roughening of copper occurs
Solution Approach 1:
The patent modifies the chemical composition parameters of the cleaning solution by incorporating specific corrosion inhibitors (benzotriazole, tolyltriazole, 5-nitrobenzotriazole) and controlling pH levels (7-11) to achieve effective cleaning while preventing copper corrosion and roughening
Solution Approach 2:
The patent introduces corrosion inhibitor compounds as intermediary substances that mediate between the cleaning action and copper surface, forming protective complexes that prevent direct corrosive interaction while allowing contaminant removal
2Reliability
If strong cleaning action is applied to remove residues, then cleaning efficacy improves, but damage to barrier materials and copper layers increases
Solution Approach 1:
The patent optimizes multiple parameters including pH (7-11), temperature (20-80°C), and concentrations of cleaning agents combined with corrosion inhibitors to achieve high cleaning efficacy while protecting sensitive materials
Solution Approach 2:
The patent creates a composite cleaning solution formulation that combines multiple ingredients including surfactants, chelating agents, and corrosion inhibitors working synergistically to provide both strong cleaning action and material protection
3Manufacturing precision
If copper seed layer thickness is reduced to prevent overhang and voids, then patterning precision improves, but cleaning becomes more difficult
Solution Approach 1:
The patent adjusts cleaning solution parameters including pH, temperature, and chemical composition to effectively remove residues from ultra-thin copper seed layers without causing corrosion or roughening, enabling cleaning of increasingly thinner layers as technology nodes scale
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 achieves significant removal of residues and contaminants, with at least 75% efficacy, preventing corrosion and ensuring smooth electrical performance by effectively cleaning microelectronic devices, including those with complex barrier layers, thereby enhancing the reliability of microelectronic devices.
Implementation Method 1
at least one etchant material chosen from amines and complexing agents
Implementation Method 2
at least one surfactant material
Implementation Method 3
at least one corrosion inhibitor
Data Source
AI summary
The disclosure generally relates to a composition and process for cleaning residue and/or contaminants from microelectronic devices having said residue and contaminants thereon. The residue may include post-CMP, post-etch, and/or post-ash residue. The compositions and methods are particularly advantageous when cleaning a microelectronic surface comprising copper, low-k dielectric materials, and barrier materials comprising at least one of tantalum-containing material, cobalt-containing material, tantalum-containing, tungsten-containing, and ruthenium-containing material.