I would like to know why I get different nitridification of iron thin film in Magnetron sputtering? by changing for few teslas only, I obtain different percent of Nitrogen in thin film,
Is there any theoretical explanation on the influence of magnetic filed on nitrogen plasma and thin film formation?
It might have something to do with the general effect a magnetic field has in magnetron sputtering. The reason a magnetic field is employed in first place is that its presence reduces the electron mobility. Electrons generated at the cathode are trapped along the field lines until they undergo collision. In other words, the residence time of electrons in cathode region is considerably increased. The presence of the magnetic field allows electrons to ionize gas much more efficient.
Stefan,
I concur with Christian that with changes in the magnetic field you effect the ionization rate of the gasses in your system (Ar and N2). The stronger the field the better the electrons are captured close to the target and the more ionization of the gasses will take place thus enhancing the concentration of reactive nitrogen species. With your application of putting a Fe target in a magnetron it probably is even more critical since Fe is magnetic and will short circuit the magnetron magnetic field. Therefore the magnetic field strength just below the target will be low and the ionization rate will also be low, making the system more vulnerable to changes in composition of your film. Did you experience ignition issues with the Fe-target or do you need to go to high pressures to get ignition? If so, the magnetic field circuit de to the Fe-target is the cause for this. You can improve this by using thin Fe-targets.
thank you both, Peter and Binek,
So basically, it is same physical phenomena as the effect of magnetic field on plasma, as we can see in nuclear physics experiments ( tokamak confinement)?
except of course this is in small scale,
about Ignition, thank you for adding this, to be honest, I didn't but I need to tell you that my Fe sample sometime oxidize very fast, ( turn into red) is this a sign of ignition?
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructures
- Thin Films