Dual-Inhibitor Polishing Slurry for CMP Rate Selectivity
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Solution Overview
Problem
The existing polishing processes for semiconductor devices face challenges in achieving efficient planarization of metal films while minimizing defects such as dishing and erosion, particularly due to inadequate control of the polishing rate ratio between metal and insulating films.
Innovation Solution
A polishing slurry composition is developed, comprising polishing particles, a hydrophobic amino acid as a first inhibitor, a cyclic polymer as a second inhibitor, an oxidizing agent, and iron ions, which work together to control the polishing rate and prevent excessive removal or recessing of the metal film, maintaining a high polishing selectivity and reducing surface defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a metal film is oxidized to polish it, then the polishing efficiency is improved, but dishing and erosion defects occur on the metal film
Solution Approach 1:
The patent introduces a dual-inhibitor system (first polishing inhibitor and second polishing inhibitor) as intermediaries that mediate between the oxidizing agent and the metal film. These inhibitors control the oxidation rate and interact with the polishing particles to prevent excessive oxidation, thereby eliminating dishing and erosion while maintaining high polishing efficiency.
Solution Approach 2:
The patent changes the chemical parameters of the polishing slurry by incorporating specific inhibitors that modify the oxidation kinetics. The first polishing inhibitor controls the oxidation rate by forming a protective layer, while the second polishing inhibitor adjusts the chemical reactivity, thereby optimizing the polishing process to avoid defects.
2Productivity
If the polishing rate for metal film is increased, then the planarization speed is improved, but the control over polishing rate ratio between metal and insulating films deteriorates
Solution Approach 1:
The patent implements a feedback mechanism through the dual-inhibitor system that responds to the polishing conditions. The inhibitors dynamically adjust the oxidation rate based on the interaction between polishing particles and the film surface, providing automatic control over the polishing rate ratio between metal and insulating films during the planarization process.
Solution Approach 2:
The patent creates a composite polishing slurry system combining multiple components (polishing particles, oxidizing agent, first polishing inhibitor, and second polishing inhibitor) that work synergistically. This composite formulation enables simultaneous optimization of polishing speed and selectivity control through the combined effects of different materials.
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 a high polishing rate with minimal protrusion step and erosion, ensuring reproducible and effective planarization of semiconductor surfaces, thereby enhancing the quality of semiconductor devices.
Implementation Method 1
a process in which a metal oxide is formed by an oxidizing agent
Implementation Method 2
a first polishing inhibitor containing a hydrophobic amino acid
Implementation Method 3
a second polishing inhibitor containing a cyclic polymer
Implementation Method 4
a process in which polishing particles are removed from the formed metal oxide
Data Source
AI summary
A polishing slurry composition is provided. The polishing slurry composition includes polishing particles, a first polishing inhibitor containing a hydrophobic amino acid, and a second polishing inhibitor containing a cyclic polymer, and the first polishing inhibitor and the second polishing inhibitor are different.