Dear all,

I have a little problem with evaporating Cr by ebeam with our system.
It is well known that Cr can be dep at high rates, presumably several
angstrom/sec.  However, for my case at the moment, at dep rate of above
1A/s, my films would peel off after soaking in solvents (ie water or
acetone etc.), even though films seems to be quite smooth under optical
mic before immersion.  After a few mins the entire films is washed off.

I had also isolated the thickness factor: Good quality film of ~300nm
was deposited at 0.5A/s.  However, when another similar deposition
(~200nm) was done atop yielding a total thickness >400nm, the entire
film peels off as above.  This could well be a stress related issue.
But how is stress affecting my film at higher dep rates, whereas others
have presumably managed to get good films without peeling problems at hi
rates.

Dep condition:
Base pressure: 2e-6 mtorr
Dep pressure: ~4e-6 mtorr
Substrate temp: 120C and Rm Temp.
Crucible used: v.carbon (traces of green material is now visble on the
rim of crucible and can be seen on Cr close to the rim of crucible as
well)
Metal used: Cr 99.999%
Target Thickness: 200 to 300 nm.
Substrate: Si or thermal SiO2/Si (substrate clean by acetone/IPA/DI
water + RTP600C/3mins)


Pls advise if possible how I maybe able to dep at higher rates with good
films.

Many thanks and best regards,
Charles K.F. Ho
vie_charlie@pmail.ntu.edu.sg