Metal Compound Anchored Colloidal Particles for CMP Slurry
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Solution Overview
Problem
Current tungsten chemical mechanical polishing (CMP) slurries face challenges in achieving superior planarization of nanostructures for semiconductor manufacturing, particularly at 28 nm technology nodes and beyond, due to issues like dishing and erosion, which require tunable removal rates and selectivity between metal and dielectric materials.
Innovation Solution
The development of metal compound chemically anchored colloidal particles, where metal compounds are uniformly bonded to colloidal particles via chemical bonding, are used as novel solid catalysts in CMP processes. These particles are created by mixing colloidal particles with a soluble metal compound precursor and an organic linking agent, forming a polishing composition that includes abrasive, oxidizer, and a liquid carrier, optimizing the pH range for effective polishing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional CMP slurries are used to achieve high tungsten removal rates, then productivity is improved, but dishing and erosion increase reducing manufacturing precision
Solution Approach 1:
The invention changes the chemical parameters of the CMP slurry by incorporating metal compounds (such as iron, copper, or nickel compounds) at controlled concentrations (0.1-10 wt%) to modify the removal rate characteristics. This allows tuning of the chemical reaction between the slurry and tungsten, achieving higher removal rates without the harmful dishing and erosion effects that occur with traditional slurries.
Solution Approach 2:
The invention creates a composite CMP slurry system that combines traditional abrasive particles with metal compound additives. This composite formulation synergistically combines the mechanical polishing action of abrasives with the chemical enhancement from metal compounds, achieving superior planarization that simultaneously improves removal rate while maintaining surface flatness and reducing edge effects.
2Productivity
If CMP slurry chemistry is optimized to increase metal removal rate, then productivity is improved, but selectivity between metal and dielectric decreases
Solution Approach 1:
The invention applies local quality by using metal compounds that selectively interact with tungsten surfaces while being relatively inert toward dielectric materials. The metal compounds concentrate their chemical action at the metal-dielectric interfaces, enhancing tungsten removal through localized chemical mechanisms that do not significantly affect dielectric materials, thereby maintaining high selectivity.
Solution Approach 2:
The metal compounds act as chemical intermediaries or mediators between the abrasive particles and the tungsten surface. These intermediaries facilitate enhanced chemical reactions that accelerate tungsten removal while the slurry formulation is designed to prevent similar reactions with dielectric materials, thus maintaining selectivity through controlled intermediary action.
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 use of metal compound chemically anchored colloidal particles enhances the CMP process by increasing tungsten removal rates while maintaining selectivity and reducing metal contamination, thereby improving planarization quality and minimizing dishing and erosion effects, thus addressing the limitations of existing CMP slurries.
Implementation Method 1
colloidal particles having metal compounds uniformly anchored to surfaces via chemical bonding
Implementation Method 2
The slurry accomplishes the planarization (polishing) process by chemically and mechanically interacting with the substrate film being planarized
Implementation Method 3
Typically metal CMP slurries contain an abrasive material, such as silica or alumina, suspended in an oxidizing, aqueous medium
Implementation Method 4
The organic linking agent chemically modifies colloidal particle surfaces, and still maintains suitable functional groups on the surface of modified particles to further allow the anchoring of water soluble metal compounds onto the particle surfaces
Data Source
AI summary
Metal compound chemically anchored colloidal particles wherein the metal compound is in molecular form are disclosed. A facile and fast process to chemically anchor metal compounds uniformly onto colloidal particle surfaces via chemical bonding has been developed. Metal compounds are chemically anchored to the surface of colloidal particles via an organic linking agent. Uniformly distributed metal compounds remain in molecular form after the process. The metal compound chemically anchored colloidal particles can be used as solid catalyst in metal chemical-mechanical planarization process.