Atomic Layer Deposition
Introduction
Atomic Layer Deposition (ALD) involves the deposition of materials one monolayer at a time and forms extremely conformal pin hole free coatings. This is achieved by pulsing a precursor (such as TriMethylAluminium -TMA) onto a hydroxilated substrate. The precusror reacts with this surface but not with itself resulting in a monolayer of material - in this case alumina. The precursor is purged from the chamber and then the surface is again hydroxilated with water vapour or oxygen (in the plasma system) followed by another purge. These two steps are then repeated until the desired thickness of material is achieved.
Applications
ALD has a vast array of applications from semiconductors, mems, nanostructures and optics through to wear resistant coatings.
Equipment
MCN has two ALD tools, the Fiji F200 and Savannah both from Cambridge Nanotech. The Savannah system is thermal only and can run with two precursors at once. It is integrated into a glovebox system therefore samples can be kept in an inert environment. The Fiji F200 is both a thermal and plasma based system. This expands the ALD window for materials by decreasing activation energy and allows:
•Lower temperature: avoids precursor decomposition
•Faster deposition cycle times
•Fewer contaminates in films
Documentation
For more information on ALD please refer to the introduction to ALD presentation from Cambridge Nanotech below:
Introduction To Atomic Layer Deposition
Contacts
For more detail about ALD at MCN or enquiries about access please contact:
For the Fiji system
Douglas Mair - douglas.mair@monash.edu
or
For the Savannah system
Zoran Vasic - zoran.vasic@monash.edu
