Abrasive-Free CMP Slurry for Metal Film Polishing Selectivity
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Solution Overview
Problem
Existing chemical mechanical polishing (CMP) processes using inorganic abrasives cause physical damage and contamination to metal-containing films in integrated circuit (IC) devices, leading to reduced lifespan and reliability, and increase manufacturing costs due to abrasive wear on polishing pads.
Innovation Solution
A slurry composition for CMP that includes a first organic polishing booster with a cationic polymer salt, a second organic polishing booster, an oxidizer, a pH adjuster, and water, without inorganic abrasives, to enhance polishing rate and selectivity of metal-containing films like copper films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If inorganic abrasives are used in CMP process, then polishing rate is improved, but physical damage and contamination to metal-containing films occurs
Solution Approach 1:
The patent removes inorganic abrasives from the CMP slurry composition entirely, extracting the harmful element while maintaining polishing functionality through organic alternatives. The slurry comprises organic polishing boosters, oxidizers, and pH adjusters without any inorganic abrasive particles, thus eliminating physical damage and contamination to metal-containing films while achieving adequate polishing rates.
Solution Approach 2:
The patent replaces the mechanical abrasion mechanism (inorganic abrasives) with a chemical-mechanical hybrid mechanism using organic polishing boosters. The organic polymers provide gentle mechanical action combined with chemical oxidation from additives like hydrogen peroxide and ammonium persulfate, achieving film removal without the harsh mechanical cutting action that causes damage.
2Productivity
If inorganic abrasives are used in CMP process, then polishing rate is improved, but manufacturing cost increases due to abrasive wear on polishing pads
Solution Approach 1:
The patent extracts inorganic abrasives from the slurry composition, eliminating the source of polishing pad wear. Without hard abrasive particles like silica or alumina, the polishing pad experiences minimal mechanical degradation, extending its service life and reducing replacement frequency and manufacturing costs.
Solution Approach 2:
The patent employs organic polishing boosters that are consumable and can be replenished in the slurry, replacing the need for durable but wear-inducing inorganic abrasives. The organic components degrade gently and can be refreshed, providing a cost-effective solution that reduces polishing pad consumption.
3Productivity
If inorganic abrasives are used in CMP process, then polishing rate is improved, but surface defects increase
Solution Approach 1:
The patent substitutes harsh mechanical abrasion with a softer chemical-mechanical process using organic polymers. The organic polishing boosters provide gentle planarization through chemical oxidation and mild mechanical action, eliminating scratches, pits, and other surface defects caused by inorganic abrasive particles while maintaining acceptable polishing rates.
Solution Approach 2:
The patent changes the physical and chemical parameters of the polishing slurry by using organic molecules with controlled molecular weights, viscosities, and chemical reactivities. These parameter adjustments enable fine-tuned control over the polishing mechanism, achieving high surface quality through chemical oxidation dominated by hydrogen peroxide and ammonium persulfate rather than mechanical cutting.
4Productivity
If inorganic abrasives are used in CMP process, then polishing rate is improved, but contamination to metal films occurs
Solution Approach 1:
The patent completely removes inorganic abrasive particles from the slurry composition, eliminating the source of contamination to metal-containing films. Without hard particulate matter, there is no risk of abrasive contamination embedding in the polished metal surfaces, ensuring cleaner and more reliable device performance.
Solution Approach 2:
The patent replaces particle-based mechanical abrasion with a dissolution-oxidation mechanism using organic polymers and chemical oxidizers. This substitution eliminates the generation of abrasive wear debris that would otherwise contaminate the metal films, achieving contamination-free polishing through chemical reactions rather than mechanical particle interaction.
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 abrasive-free slurry composition improves polishing rates and selectivity of metal films, reduces surface defects, and minimizes contamination and pad abrasion, thereby enhancing IC device reliability and lowering manufacturing costs.
Implementation Method 1
an oxidizer
Implementation Method 2
a first organic polishing booster including a cationic polymer salt that includes a quaternary ammonium cation
Data Source
AI summary
A slurry composition for polishing metal and a method of manufacturing an integrated circuit device, the slurry composition includes a first organic polishing booster including a cationic polymer salt that includes a quaternary ammonium cation; a second organic polishing booster including an organic acid; an oxidizer; a pH adjuster; 0 wt % to about 0.1 wt % of an inorganic abrasive; and water.