Copper CMP Slurry Chemistry for Higher Polishing Rate

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Solution Overview

Problem

Current polishing liquids used in CMP technology for copper processing have limitations in achieving a high polishing rate, necessitating the development of a more effective solution to enhance copper removal efficiency.

Innovation Solution

A polishing liquid containing cerium oxide abrasive grains and an ammonium salt, such as ammonium carbonate or ammonium persulfate, with a pH of 9.00 or more, along with additives like ammonia and polyglycerol, is used to improve the polishing rate for copper surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional polishing liquids are used for copper processing, then the polishing process can be performed, but the polishing rate for copper is insufficient

Engineering Contradiction:
Improvepolishing rateVSAvoidpolishing effectiveness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the polishing liquid by adjusting pH to 9.00 or more and incorporating specific ammonium salts (ammonium carbonate, ammonium persulfate) and complexing agents (ammonia, polyglycerol). These parameter changes enable the polishing liquid to form soluble copper-ammonia complexes, dramatically improving the polishing rate for copper surfaces while maintaining process reliability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite polishing liquid system combining cerium oxide abrasive grains with a chemically active slurry containing ammonium salts, ammonia, and polyglycerol. This composite formulation synergistically combines mechanical abrasion with chemical complexation, where the cerium oxide provides mechanical removal and the ammonium-based chemicals enhance copper dissolution through complex formation, achieving superior polishing rates

Inventive Principle:
Principle #40Composite materials

2Productivity

If the polishing rate for copper is increased, then copper removal efficiency is improved, but the complexity of the polishing liquid composition increases

Engineering Contradiction:
Improvecopper removal efficiencyVSAvoidpolishing liquid composition
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent employs ammonium-based chemicals that serve multiple functions simultaneously: ammonium carbonate and ammonium persulfate provide both pH control and copper complexation capabilities, while ammonia acts as both a complexing agent and a pH regulator. This multi-functionality reduces the need for separate additives, simplifying the overall composition while maintaining high copper removal efficiency

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

By optimizing the pH to 9.00 or more and controlling the concentrations of ammonium salts and complexing agents within specific ranges, the patent achieves maximum copper complexation efficiency. This parameter optimization ensures high copper removal rates while avoiding excessive complexity in the formulation, as the system operates most effectively within these defined parameter boundaries

Inventive Principle:
Principle #35Parameter changes

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 proposed polishing liquid achieves a significant improvement in copper polishing rate, with demonstrated rates exceeding 0.35 μm/min, effectively addressing the limitations of existing technologies by forming complexes that accelerate copper removal.

Implementation Method 1

forming complexes that accelerate copper removal

Methodology Applied
Scientific EffectComplex formation: Chemical Bonding

Implementation Method 2

a polishing liquid containing abrasive grains containing cerium oxide

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentUS20240392162A1Polishing liquid, polishing method, component manufacturing method, and semiconductor component manufacturing method
Publication Date: 2024.11.28 RESONAC CORP

AI summary

A polishing liquid containing abrasive grains containing cerium oxide and an ammonium salt, in which a pH is 9.00 or more. A polishing method including polishing a member to be polished containing copper by using the above-described polishing liquid. A method for manufacturing a component, including obtaining a component by using a polished member polished by the above-described polishing method. A method for manufacturing a semiconductor component, including obtaining a semiconductor component by using a polished member polished by the above-described polishing method.