CMP Slurry Particle Size Control via Semi-Permeable Membrane

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Solution Overview

Problem

The effectiveness of chemical mechanical planarization slurries in microelectronics fabrication is hindered by the size of abrasive particles, as smaller particles can contaminate or fuse together, leading to irregularities in microelectronic features.

Innovation Solution

A method and system using a semi-permeable fiber membrane to separate abrasive particles in a chemical mechanical planarization slurry precursor, creating a concentrate with larger particles and an effluent with smaller particles, maintaining a pressure difference of 1 psi to 15 psi to control particle size distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If smaller abrasive particles are used in the slurry, then the planarization effectiveness is improved, but particle contamination and fusion issues worsen

Engineering Contradiction:

Improveplanarization effectivenessVSAvoidparticle contamination and fusion

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the particle size parameter by using a semi-permeable membrane with specific pore sizes to separate and select abrasive particles within a narrow size range (20-100 nm), transforming the slurry from containing mixed or smaller particles to containing only controlled-size particles that maintain effectiveness without fusion issues

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent extracts harmful smaller particles from the slurry mixture by passing the slurry precursor through a semi-permeable membrane that retains particles smaller than the desired size while allowing larger particles to pass, thereby removing the contamination and fusion problem sources

Inventive Principle:

Principle #2Taking out (Extraction)

2Manufacturing precision

If a semi-permeable membrane separation process is used to control particle size, then particle size distribution precision is improved, but manufacturing complexity increases

Engineering Contradiction:

Improveparticle size distributionVSAvoidmembrane separation system

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent introduces a semi-permeable membrane as an intermediary component between the slurry precursor and final slurry product. This membrane acts as a selective filter that passively separates particles based on size without requiring complex active control systems, achieving precise particle size distribution through its inherent pore structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces complex mechanical particle size control systems (such as multiple filtration stages or centrifugal separation) with a simpler membrane-based separation approach, where the separation function is achieved through the membrane's intrinsic properties rather than complex mechanical mechanisms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Ease of manufacture

If abrasive particles are retained in the slurry without separation, then the slurry formulation is simple, but particle size control and slurry effectiveness deteriorate

Engineering Contradiction:

Improveslurry formulation simplicityVSAvoidparticle size control

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent performs preliminary particle size separation by passing the slurry precursor through a semi-permeable membrane before the slurry is used in the planarization process. This preliminary action ensures that only particles within the desired size range (20-100 nm) are present in the final slurry, achieving precise particle size control while maintaining ease of manufacture through a single-step separation process

Inventive Principle:

Principle #10Preliminary action

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 process effectively produces a chemical mechanical planarization slurry with a majority of abrasive particles having a median size greater than 20 nm, reducing contamination and fusion issues, thereby enhancing the planarization process.

Implementation Method 1

separating the chemical mechanical planarization slurry precursor into a concentrate and an effluent by passing the chemical mechanical planarization slurry precursor through the semi-permeable fiber membrane

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Data Source

PatentUS20220411686A1Particulate slurries and methods of making the same

Publication Date: 2022.12.29 SOLVENTUM INTELLECTUAL PROPERTIES CO

AI summary

The present disclosure provides a method of making a chemical mechanical planarization slurry. The method includes contacting a chemical mechanical planarization slurry precursor including a carrier and a plurality of abrasive particles with a semi-permeable fiber membrane. Upon contact, the method further includes separating the chemical mechanical planarization slurry precursor into a concentrate and an effluent. The concentrate includes the chemical mechanical planarization slurry and the effluent includes the carrier and a plurality of particles. The particles of the effluent have a median size that is less than a median size of the abrasive particles of the concentrate. In the method a pressure difference measured between an inlet to which the chemical mechanical planarization slurry precursor is supplied and a first outlet to which the effluent is supplied is in a range of from about 1 psi to about 15 psi.