Polishing Slurry Composition for Multi-Selectivity in Semiconductor CMP
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The chemical mechanical polishing (CMP) process in semiconductor manufacturing faces challenges with complex surface structures and high step heights, leading to defocusing issues and increased costs due to difficulty in controlling and maintaining dispersion stability of the polishing slurry, which complicates the process and requires frequent slurry replacements.
Innovation Solution
A polishing slurry composition is developed, comprising abrasive particles with a positive charge and an additive liquid containing a polymer with an amide bond and a cationic polymer, allowing for multi-selectivity and adjustable polishing speed, which includes specific polymers and amino acids to enhance dispersion stability and control polishing rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If an additive is injected to secure polishing rate of silicon nitride membrane, then polishing selectivity is improved, but slurry dispersion stability deteriorates
Solution Approach 1:
The patent introduces a dispersant as an intermediary substance that mediates between the abrasive particles and the polishing slurry. The dispersant contains specific functional groups (carboxyl, hydroxyl, or amine groups) that interact with both the abrasive particles and the slurry matrix, maintaining dispersion stability while allowing the additive to function effectively for achieving polishing selectivity between silicon nitride and silicon oxide films.
Solution Approach 2:
The invention creates a composite slurry system combining abrasive particles, polishing slurry, additive, and dispersant. This composite formulation allows the additive to provide polishing selectivity while the dispersant component maintains dispersion stability, resolving the contradiction between achieving high selectivity and maintaining stable slurry properties throughout the polishing process.
2Reliability
If slurry replacement is performed for each process, then polishing performance is maintained, but process complexity and cost increase
Solution Approach 1:
The patent develops a universal polishing slurry composition that can be used across multiple polishing processes without requiring replacement. The slurry formulation with controlled dispersion stability and multi-selectivity enables it to effectively polish different film types (silicon oxide, silicon nitride, polysilicon) in various semiconductor manufacturing processes, eliminating the need for process-specific slurry changes and reducing overall process complexity.
3Productivity
If multi-selectivity is implemented, then polishing rate control is improved, but slurry formulation complexity increases
Solution Approach 1:
The patent achieves multi-selectivity by carefully controlling parameters of the slurry composition, including particle size distribution (0.1-10 μm range), pH value (2-11 range), and the types and concentrations of functional groups in the dispersant and additive. By optimizing these parameters within specific ranges, the slurry can selectively polish different film materials at controlled rates without requiring excessively complex formulation, balancing productivity with manageable formulation complexity.
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 enables effective multi-selectivity and adjustable polishing speed, reducing surface flaws and costs by maintaining dispersion stability and allowing for precise control of polishing processes, thereby improving the CMP process efficiency in semiconductor manufacturing.
Implementation Method 1
the additive liquid includes a polymer having an amide bond, and a cationic polymer
Implementation Method 2
a polymer having an amide bond may include at least one of polymers represented by Chemical Formula 1
Implementation Method 3
a polishing liquid including abrasive particles
Implementation Method 4
maintaining dispersion stability of the slurry
Data Source
AI summary
A polishing slurry composition enabling implementation of multi-selectivity is provided. The polishing slurry composition includes: a polishing liquid including abrasive particles; and an additive liquid, in which the additive liquid includes a polymer having an amide bond, and a cationic polymer.