Antioxidant Cleaning Formulation for Post-CMP Residue Removal
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Solution Overview
Problem
Conventional cleaning chemistries for microelectronic devices often damage low-k dielectric materials, absorb into the pores of interlevel dielectric layers, corrode metal structures, and fail to effectively remove residues such as CMP material and corrosion inhibitor compounds like benzotriazole, leading to poor adhesion and electrical performance issues.
Innovation Solution
A cleaning composition comprising a solvent, a corrosion inhibitor selected from cyanuric acid, barbituric acid, glucuronic acid, and other antioxidants, along with additional components like quaternary bases, surfactants, and dispersing agents, which effectively removes post-CMP, post-etch, and post-ash residues without damaging metal interconnects or low-k dielectric materials.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional cleaning chemistries are used to remove residues, then residue removal capability is improved, but damage to metal interconnects and low-k dielectric materials occurs
Solution Approach 1:
The patent changes the chemical parameters of the cleaning composition by using antioxidants in controlled concentrations (e.g., 0.01-5% weight percent) to achieve effective residue removal while controlling the aggressiveness of the chemistry to prevent damage to sensitive materials
Solution Approach 2:
The cleaning composition is formulated as a composite system containing multiple components including antioxidants, chelating agents, surfactants, and buffers that work synergistically to remove residues while protecting sensitive materials through the combined effects of different chemical mechanisms
2Reliability
If strong cleaning chemistries are used to remove CMP material and corrosion inhibitors, then cleaning effectiveness is improved, but adhesion of subsequent layers deteriorates
Solution Approach 1:
The patent optimizes the pH and chemical composition parameters to achieve effective removal of CMP residues and corrosion inhibitors while maintaining surface properties that support good adhesion of subsequent layers, avoiding overly aggressive chemistry that would compromise surface integrity
3Device complexity
If conventional cleaning compositions are used, then formulation simplicity is maintained, but electrical performance reliability deteriorates
Solution Approach 1:
The patent develops a composite cleaning formulation containing antioxidants, chelating agents, surfactants, and buffers that work together to remove residues and protect materials, achieving reliable electrical performance through the synergistic combination of multiple functional components
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 substantial removal of residues (>95%) while maintaining the integrity of metal and dielectric materials, ensuring reliable electrical performance and adhesion of subsequent layers.
Implementation Method 1
the layers that must be removed and planarized include copper layers... separated from the dielectric material surface by a layer of barrier material... which prevents diffusion of copper into the oxide dielectric material
Implementation Method 2
Such residues include CMP material and corrosion inhibitor compounds such as benzotriazole (BTA)... The cleaning compositions described herein include at least one novel antioxidant as a corrosion inhibitor
Implementation Method 3
The cleaning compositions described herein include at least one novel antioxidant as a corrosion inhibitor... effective for the removal of residue from a microelectronic device
Implementation Method 4
CMP involves applying slurry, e.g., a solution of an abrasive and an active chemistry, to a polishing pad that buffs the surface
Data Source
AI summary
An cleaning composition and process for cleaning post-chemical mechanical polishing (CMP) residue and contaminants from a microelectronic device having said residue and contaminants thereon. The cleaning compositions include novel corrosion inhibitors. The composition achieves highly efficacious cleaning of the post-CMP residue and contaminant material from the surface of the microelectronic device without compromising the low-k dielectric material or the copper interconnect material.