CMP Slurry with Zirconyl Compound for Silicon Dioxide Removal

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Solution Overview

Problem

There is a need for improved methods of chemical mechanical polishing of substrates with exposed silicon dioxide features, as existing techniques do not achieve sufficient removal rates.

Innovation Solution

A chemical mechanical polishing composition containing colloidal silica abrasive and a zirconyl compound, with a pH of ≤6, is used in conjunction with a polishing pad to create dynamic contact, significantly increasing the silicon dioxide removal rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional CMP compositions are used, then the polishing process is simple, but the silicon dioxide removal rate is insufficient

Engineering Contradiction:
Improvesilicon dioxide removal rateVSAvoidcomposition complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent changes the chemical parameters of the CMP composition by introducing a zirconyl compound and adjusting the pH to ≤6, which transforms the removal mechanism from oxidation-based to complexation-based, achieving over 500% higher silicon dioxide removal rate

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite chemical system combining colloidal silica abrasive with zirconyl compound (such as zirconyl nitrate or zirconyl chloride), where the zirconyl compound forms soluble complexes with silicon dioxide, enhancing the removal rate dramatically

Inventive Principle:
Principle #40Composite materials

2Productivity

If higher down force is applied, then the removal rate increases, but the risk of substrate damage increases

Engineering Contradiction:
Improveremoval rateVSAvoidsubstrate integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent replaces the mechanical removal mechanism with a chemical complexation mechanism using zirconyl compound, allowing efficient silicon dioxide removal at lower down forces (0.69 to 34.5 kPa) without compromising substrate integrity

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 method achieves a silicon dioxide removal rate greater than 500% higher than identical compositions without the zirconyl compound, effectively planarizing substrates with exposed silicon dioxide features.

Implementation Method 1

a zirconyl compound... wherein the substrate is polished; wherein some of the exposed silicon dioxide feature is removed from the substrate

Methodology Applied
Scientific EffectComplexation: Chemical Bonding

Implementation Method 2

0.01 to 40 wt % of a colloidal silica abrasive... creating dynamic contact at the interface between the chemical mechanical polishing pad and the substrate

Methodology Applied
Scientific EffectAbrasion: Abrasion

Data Source

PatentUS9293339B1Method of polishing semiconductor substrate
Publication Date: 2016.03.22 DUPONT ELECTRONIC MATERIALS HLDG INC

AI summary

A process for chemical mechanical polishing of a substrate having an exposed silicon dioxide feature is provided comprising: providing a chemical mechanical polishing composition, containing, as initial components: water, a colloidal silica abrasive and a zirconyl compound; wherein a pH of the chemical mechanical polishing composition is ≦6; providing a chemical mechanical polishing pad with a polishing surface; dispensing the chemical mechanical polishing composition onto the polishing surface of the chemical mechanical polishing pad in proximity to an interface between the chemical mechanical polishing pad and the substrate; and, creating dynamic contact at the interface between the chemical mechanical polishing pad and the substrate; wherein the substrate is polished.