Dear Jungwook,
For your crucible, a good source to check this kind of thing is the
Kurt Lesker Co's technical data site:
http://www.lesker.com/newweb/menu_techinfo.cfm?section=materials&init=skip
For Ni, they suggest either Al2O3, BeO, or VC (vitreous carbon)
crucibles, but *not* graphite. That's likely to be one problem.
Secondarily, you should also make sure you're not heating up the
crucible too quickly. Every machine is different, but increasing your
power by 5-10 mA per 10 seconds should be in the right ballpark to
avoid excessively fast heating.
As for using an adhesion layer, I'd recommend it. I've always used Ti
(10 to 20 nm thick) for Ni, but I suspect Cr will work also.
- Kevin
Kevin P Nichols, Ph.D.
Postdoctoral Scholar
Ismagilov Group
Department of Chemistry
Gordon Center CIS E305
University of Chicago
929 East 57th Street
Chicago, IL 60637
E: kpnichols@uchicago.edu
T: 773-834-8474
F: 773-834-3544
On Fri, Sep 25, 2009 at 1:32 AM, Jungwook Choi wrote:
> Dear all,
>
> I tried to deposit 100 nm nickel film on silicon wafer by using e-beam or
> thermal evaporator. In both cases, the nickel pellets were utilized as a
> source.
>
> In the case of e-beam evaporation, the deposition rate was not over 0.1~0..2
> A/s. When I increased e-beam power to increase deposition rate, the graphite
> crucible was broken with cracks. Is there anyone that has experience to
> evaporate nickel using e-beam evaporation? Which type of nickel sources is
> adequate for this?
>
> Similarly, in the case of thermal evaporation, the tungsten boat was
> suddenly broken before evaporating nickel. The holes were observed in the
> broken tungsten boat. How to avoid the failure of tungsten boat? If I
> replace a tungsten boat to a tungsten helix coil with nickel wires as a
> source, could it be better in thermal evaporation?
>
> Any suggestions and comments would be highly appreciated regarding above
> issues.
>
> Additionally, does adhesion layer such as Cr and Ti is needed to deposit
> nickel on silicon? What is the optimum thickness of the adhesion layers?
>
> Thanks,
>
> J. Choi