Tommi

I had similar problems with Tungsten sputtering a while back. It sounds
like there is no plasma striking and what you are seeing is not a plasma
but just a small discharge field.  We found the plasma tends to strike at
fairly high pressures, around 2x10^-3 mbar and a decent deposition rate
without too much damage to the surface occurs below 10 mW DC power.

hope this helps

Greg Chance
Terehertz Technology Group
Bath University
BA1 2LY   UK


--On 05 April 2004 15:33 +0300 Tomi Meilahti 
wrote:

> Hi everybody,
> We recently purchased an aluminium target for the companys rather old
> Leybold-Heraeus (model Z 400 I think) sputtering system. The problem is I
> can´t find working sputtering parameters for it. Either there is no
> aluminium coating on the test wafer at all or then the coating is of very
> dark colour. The process looks OK when I look through the small windows
> on the chamber walls. I´ve tried varying sputtering pressure and voltage.
> Any ideas or suggestions would be greatly appreciated. Best regards
> Tomi Meilahti
> Metorex International Oy
> Nihtisillankuja 5
> 02631 Espoo
> Puh: 09 32941316
> Fax: 09 32941301
> E-mail: tomi.meilahti@metorex.fi