CMP Slurry Composition for Reduced Oxide Dishing in Interconnects

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The semiconductor industry faces challenges in manufacturing smaller, more reliable ICs due to severe oxide dishing during chemical mechanical polishing (CMP), which can result in non-uniform planarization and reduced device reliability.

Innovation Solution

The use of a CMP slurry containing an abrasive and a compound with positively charged ions, such as tetraethylammonium hydroxide (TEAH), to reduce the aggregation of abrasive particles on the dielectric structure, thereby minimizing oxide dishing and achieving a flush surface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional CMP slurry is used, then polishing action is achieved, but oxide dishing occurs and planarization uniformity deteriorates

Engineering Contradiction:

Improveplanarization uniformityVSAvoidoxide dishing

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a mediator substance (polymer or surfactant) into the CMP slurry that acts as an intermediary between the abrasive particles and the oxide surface. This mediator prevents direct aggregation of abrasive particles on the oxide, reducing dishing while maintaining polishing effectiveness. The mediator modifies the interaction mechanism to achieve more uniform material removal.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the chemical composition parameters of the CMP slurry by adding specific polymers or surfactants with controlled concentrations, molecular weights, and charge characteristics. These parameter changes modify the slurry's interaction with the oxide surface, preventing abrasive aggregation and reducing dishing while maintaining polishing rate.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If feature sizes are reduced, then functional density increases, but manufacturing reliability deteriorates

Engineering Contradiction:

Improvefunctional densityVSAvoiddevice reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The patent employs fluid dynamics principles by optimizing slurry flow characteristics and delivery mechanisms to ensure uniform slurry distribution across the wafer surface during CMP. This hydraulic control ensures consistent polishing pressure and slurry replenishment, which is critical for maintaining reliability in smaller feature size devices.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Productivity

If CMP polishing rate is increased, then manufacturing efficiency improves, but surface topography uniformity deteriorates

Engineering Contradiction:

Improvepolishing efficiencyVSAvoidsurface topography uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent creates a composite CMP slurry system combining abrasive particles with polymer or surfactant matrices. This composite structure allows the slurry to maintain high polishing rates through abrasive action while the polymer/surfactant matrix prevents excessive material removal and maintains surface uniformity by controlling abrasive particle behavior.

Inventive Principle:

Principle #40Composite materials

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 solution effectively reduces oxide dishing, improves the post-polishing topography of dielectric structures, and enhances the reliability of semiconductor devices by maintaining a flush surface with reduced height variations.

Implementation Method 1

chemical mechanical polishing (CMP)

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

oxidizing agent configured to promote dissolution of a metallic material

Methodology Applied

Scientific EffectDissolution:

Implementation Method 3

ammonium salt having positively charged ions that interact with the abrasive to reduce aggregation of the abrasive on the dielectric material

Methodology Applied

Scientific EffectElectrostatic interaction: Electrostatics

Data Source

PatentUS20250038008A1Methods for chemical mechanical polishing and methods for forming an interconnect structure of a semiconductor device

Publication Date: 2025.01.30 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Methods for chemical mechanical polishing (CMP), and methods for forming an interconnect structure of a semiconductor device are provided. The methods include performing CMP on a surface of a dielectric structure with a CMP slurry to remove a portion of a metal layer formed in the dielectric structure and having at least a first layer exposed through the surface. In some examples, the CMP slurry that includes an abrasive, an oxidizing agent, and a compound configured to reduce aggregation of the abrasive on the surface of the dielectric structure. In some examples, the compound has positively charged ions that interact with the abrasive to reduce aggregation of the abrasive on a dielectric material. In some examples, the CMP slurry includes potassium hydroxide. In some examples, the compound includes an ammonium salt.