CMP Slurry with Cocoon Particles and Carbonate Salt

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Solution Overview

Problem

Current chemical mechanical polishing (CMP) compositions in the semiconductor industry face challenges in achieving high material removal rates for certain substrates like tantalum nitride while maintaining low removal rates for copper and low-k materials, with issues of phase separation and hazardous by-products, and require complex processes.

Innovation Solution

A CMP composition comprising cocoon-shaped inorganic particles, an amphiphilic non-ionic polyoxyethylene-polyoxypropylene alkyl ether surfactant, a carbonate or hydrogen carbonate salt, and an alcohol in an aqueous medium, which provides improved selectivity and stability, allowing for efficient polishing of substrates like tantalum nitride and low-k materials with minimal hazardous by-products and simplified process steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional CMP compositions are used to achieve high material removal rate for barrier layers, then the polishing efficiency improves, but the material removal rate for copper and low-k materials increases uncontrollably

Engineering Contradiction:
Improvematerial removal rate of barrier layerVSAvoidselectivity of material removal rate
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the chemical parameters of the CMP composition by incorporating specific carbonate salts (sodium carbonate, potassium carbonate, or ammonium carbonate) at controlled concentrations (0.01-5 wt%). This parameter change modifies the chemical reactivity of the slurry, enabling high MRR for barrier layers through enhanced chemical etching while the carbonate ions regulate the overall reaction kinetics to maintain low MRR for copper and low-k materials, thus achieving the required selectivity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite CMP composition system that combines traditional abrasive particles with carbonate salt additives and surfactants. This composite formulation synergistically integrates mechanical abrasion with controlled chemical reactions, where the carbonate salts provide selective chemical etching for barrier layers while the surfactants modulate the interaction between slurry components and different substrate materials, achieving both high productivity and precision

Inventive Principle:
Principle #40Composite materials

2Manufacturing precision

If complex CMP processes are applied to achieve desired polishing performance, then the polishing quality improves, but the process complexity and costs increase

Engineering Contradiction:
Improvepolishing qualityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The invention develops a universal CMP composition formulation that can polish multiple different substrate types (barrier layers, copper, low-k materials) with appropriate selectivity using a single slurry recipe. The carbonate salt-based system provides multi-functional chemistry that simultaneously achieves chemical etching, pH buffering, and selectivity control, eliminating the need for multiple specialized polishing steps or complex process sequences

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

3Productivity

If conventional CMP compositions are used for polishing, then the polishing process can proceed, but phase separation occurs and hazardous by-products are generated

Engineering Contradiction:
Improvepolishing process continuityVSAvoidhazardous by-products and phase separation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention converts potentially harmful by-products into beneficial components. The carbonate salts react to form carbonic acid intermediates that decompose into carbon dioxide and water, transforming what could be hazardous chemical reactions into benign products. Additionally, the carbonate buffer system converts pH fluctuations into controlled buffering action, preventing uncontrolled chemical reactions that would generate harmful by-products while maintaining stable polishing conditions

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 CMP composition achieves high material removal rates for barrier layers and low-k materials, maintains low removal rates for copper, and exhibits long shelf-life and stability, ensuring effective and safe polishing with reduced complexity and costs.

Implementation Method 1

a non-ionic surfactant, wherein (B) is an amphiphilic non-ionic polyoxyethylene-polyoxypropylene alkyl ether surfactant

Methodology Applied
Scientific EffectSurfactant: Surfactant

Implementation Method 2

a carbonate or hydrogen carbonate salt

Methodology Applied
Scientific EffectBuffering:

Data Source

PatentEP2870212B1A chemical mechanical polishing composition comprising a non-ionic surfactant and a carbonate salt
Publication Date: 2018.10.17 BASF SE
  • EP2870212B1 patent drawingFigure 1~3
  • EP2870212B1 patent drawingFigure 4
  • EP2870212B1 patent drawing

AI summary

A chemical mechanical polishing composition comprising: (A) Inorganic particles, organic particles, or a mixture or composite thereof, wherein the particles are cocoon-shaped, (B) a non-ionic surfactant, (C) a carbonate or hydrogen carbonate salt, (D) an alcohol, and (M) an aqueous medium. A process for the manufacture of semiconductor devices comprising the chemical mechanical polishing of a substrate used in the semiconductor industry in the presence of a CMP composition and the use of CMP composition thereof are also provided.