Plasma colour in a sputtering chamber

teoporta

Hi everyone,
my question is: what information can someone get by just looking at the colour of a plasma?
I the elements inside the chambers, together with some(few) common impurities.

Using the common spontaneous emission formula i can guess what transition emitted light with a particular frequency, but i don't have any database to make that data meaningful...

thank you

Astronuc

Inductively-coupled plasma optical emission spectroscopy is a common method for analyzing elements in a material.

http://www.wfu.edu/chemistry/courses...icpreprint.pdf

One would need to calibrate one's system with a standard. One usually uses a standard obtained NIST.

There are other techniques for surface analysis:
http://www.chem.qmul.ac.uk/surfaces/scc/

ZapperZ

Actually, I'm not sure if you can make such analysis of the glow in a plasma used for sputtering.

In a reactive sputtering where the sputtered specie react with a gas that has been backfilled, you can tell the difference in the color between reactive and non-reactive, i.e. you detect a qualitative difference. However, whether you can make elemental analysis from the color, that I haven't seen done before.

Zz.

teoporta

I see. Thank you for both your answers.
In my case it's normal magnetron sputtering.
Can a different amount of oxigen in the chamber change the colour of the plasma?
I'm sputtering using a Ti target:
If plasma is green it forms a Ti film, if it's light blue it forms TiO2 film...