Cobalt CMP Composition with Non-Peroxide Oxidizers for Stable Planarization
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Solution Overview
Problem
Current chemical-mechanical polishing (CMP) methods for cobalt in integrated circuits face limitations with hydrogen peroxide as an oxidizing agent, including compatibility issues and pot-life stability, necessitating alternative oxidizing agents for high cobalt removal rates and efficient planarization with low dishing and erosion.
Innovation Solution
A CMP composition comprising an abrasive, a cobalt accelerator, and an oxidizing agent selected from nitro compounds, nitroso compounds, N-oxide compounds, nitrite compounds, nitrate compounds, hydroxylamine compounds, and oxime compounds, with a pH range of 4 to 10, is used to polish substrates, enhancing cobalt removal rates and planarization efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrogen peroxide is used as an oxidizing agent in cobalt CMP composition, then cobalt removal rate and planarization efficiency are improved, but compatibility with other slurry components and pot-life stability deteriorate
Solution Approach 1:
The patent changes the chemical identity of the oxidizing agent from hydrogen peroxide to alternative compounds (nitro, nitroso, N-oxide, nitrite, nitrate, hydroxylamine, or oxime compounds), fundamentally altering the chemical parameters of the slurry system to achieve both high removal rates and improved stability
Solution Approach 2:
The patent replaces the unstable but effective hydrogen peroxide with alternative oxidizing agents that provide similar or superior performance with enhanced shelf life and stability, effectively substituting a short-lived component with more stable alternatives
2Productivity
If hydrogen peroxide is used as an oxidizing agent in cobalt CMP composition, then cobalt removal rate and planarization efficiency are improved, but compatibility with other slurry components deteriorates
Solution Approach 1:
The patent changes the chemical identity of the oxidizing agent from hydrogen peroxide to alternative compounds (nitro, nitroso, N-oxide, nitrite, nitrate, hydroxylamine, or oxime compounds), fundamentally altering the chemical parameters of the slurry system to achieve both high removal rates and improved stability
Solution Approach 2:
The patent presents multiple alternative oxidizing agent options that can all function effectively in cobalt CMP applications, providing versatility and adaptability in slurry formulation while maintaining high removal rates and compatibility with other 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 proposed solution achieves improved cobalt removal rates and planarization efficiency with reduced dishing and erosion, outperforming hydrogen peroxide-based compositions by utilizing alternative oxidizing agents that maintain stability and compatibility within the specified pH range.
Implementation Method 1
an oxidizing agent that oxidizes a metal, wherein the oxidizing agent is selected from a nitro compound, a nitroso compound, an N-oxide compound, a nitrite compound, a nitrate compound, a hydroxylamine compound, an oxime compound
Implementation Method 2
The polishing of the substrate typically is further aided by the chemical activity of the polishing composition and/or the mechanical activity of an abrasive suspended in the polishing composition
Data Source
AI summary
The invention provides a chemical-mechanical polishing composition comprising (a) an abrasive, (b) a cobalt accelerator, and (c) an oxidizing agent that oxidizes a metal, wherein the polishing composition has a pH of about 4 to about 10. The invention further provides a method of chemically-mechanically polishing a substrate with the inventive chemical-mechanical polishing composition. Typically, the substrate contains cobalt.