This might be related with the pressure inside of the chamber. Can you
observe it? The blue colored plasma is usually associated with the lower
pressure.
Darius
-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Huisheng JIAO
Sent: Monday, July 10, 2006 11:48 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Plasma colour
Dear All:
Anybody can advise me the relationship between the colour of plasma and the
temperature of the vacuum chamber? When sputtering at room temperature, the
plsama shows purple colour; but when the chamber cooled by liquid nitrogen,
plasma changes to bule colour. what is the reason? Thanks in advance,