Composite Particles for CMP Slurry
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Solution Overview
Problem
Chemical mechanical planarization (CMP) processes in semiconductor manufacturing face challenges with trade-offs between removal rate and defectivity, as well as issues related to planarization uniformity, scratching, and residual particle debris, which affect the quality and efficiency of the manufacturing process.
Innovation Solution
The use of composite particles comprising organosilica particles disposed about core particles, which are formulated into a slurry or incorporated into CMP polishing pads, providing a combination of large and small sizes, softer and harder materials, to enhance removal rates while reducing defectivity and improving cleanability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional CMP slurry with single-phase particles is used, then the process is simple to operate, but removal rate and defectivity control cannot be optimized simultaneously
Solution Approach 1:
The patent employs composite particles consisting of a soft polymer core (e.g., polyurethane, polyester, or acrylic resin) coated with hard inorganic abrasive material (e.g., silica, alumina, or ceria). This composite structure allows the soft core to reduce scratching and improve planarization uniformity while the hard outer layer maintains high removal rate. The dual-phase composition directly resolves the contradiction between productivity and manufacturing precision by combining materials with complementary properties.
Solution Approach 2:
The composite particle structure implements local quality differentiation: the inner polymer core provides softness and compliance for uniform contact, while the outer inorganic shell provides hardness for effective material removal. This spatial differentiation of material properties within a single particle enables simultaneous optimization of removal rate and defectivity control.
2Productivity
If harder polishing pads are used to improve removal rate, then productivity increases, but within-die thickness uniformity deteriorates
Solution Approach 1:
The patent changes the physical-chemical parameters of the abrasive particles by using composite structure with controlled core size (50-500 nm), shell thickness (10-100 nm), and material composition. These parameter optimizations allow the particles to maintain high removal rate while providing gentler, more uniform polishing action that improves within-die thickness uniformity compared to conventional hard particles.
3Manufacturing precision
If smaller abrasive particles are used to reduce scratching, then manufacturing precision improves, but removal rate decreases
Solution Approach 1:
The composite particle design allows small core particles (50-500 nm) to provide smooth surface polishing with minimal scratching, while the hard inorganic shell coating (10-100 nm thick) compensates for the small size by providing concentrated abrasive action. This enables small particles to maintain high removal rate that would normally be associated with larger particles, thus resolving the contradiction between surface smoothness and removal rate.
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 composite particles improve removal rates by 0-50% and reduce defectivity by 10-90%, facilitating easier post-CMP cleaning and maintaining substrate quality, thus addressing the trade-offs in CMP performance.
Implementation Method 1
the organosilica particles are derived from reaction of an organosilane compound
Implementation Method 2
the organosilica particles are derived from reaction of an organosilane compound
Implementation Method 3
Chemical mechanical planarization, also known as CMP is a technique used to planarize the top surface of an in-process semiconductor wafer or other substrates
Data Source
AI summary
CMP processes, tools and slurries utilize composite particles that include core particles having organosilica particles disposed about the core particles. Using these processes, tools and slurries can enhance removal rates, reduce defectivity and increase cleanability with respect to comparable systems and substrates.