CONTEXT

Powder characterization methods are known to be inefficient for submicron particles and very few can be used for in-situ characterisation.

This invention provides a simple characterization method of trapped submicron particles in radio frequency plasma reactors.

TECHNICAL DESCRIPTION

In RF (Radio Frequency) capacitively coupled plasma, DC self bias and RF voltage amplitude change after the creation or the intrusion of particles in the plasma.

It was demonstrated that DC self bias and RF voltage amplitude depend on the dust particle radius and density and reactor geometry.

As shown in the figure bellow the calculated radius through this invention is equal to the measured radius by TEM (Transmission Electron Microscopy).

DEVELOPMENT STAGE

The laboratory can provide a demonstration of the performance of this method.
Based on the same invention, a more simple and stable method is currently under development.

BENEFITS

As a method for determining the radius and/or density of submicron particles in radio frequency plasma, this invention can provide:

• in-situ characterisation,
• non intrusive characterisation and
• real time characterisation.

INDUSTRIAL APPLICATIONS

This invention provides quantitative characterizations of dry processes in which nano/micro particles are involved.

Main applications are:

• in-situ sampling and characterisation for nano/micro particles synthesis
• detection and following the growth/reduction of  dust (particles) in plasma processes or
• plasma characterisation to avoid dust (particles) contaminants.

For further information, please contact us (Ref 01880-01)