Hello,

I'm looking for a recipe to clean sapphire substrate. This is to study the
epitaxial growth of AlN on sapphire.
I like to know the chemical preparations of sapphire (in acides) and the
thermal treatments under vacuum  that can lead to a clean surface for
epitaxy. And, what is the state of the sapphire surface after treatment ?
Any hepl is wellcome.
Best regards,
Vincent Mortet.