precursor: La(thd)3
[solid with low vapour pressure]
plasma gas: O2
(does not react thermally with H2O)
dose control by fast pulse ALD valve
bubbled at 190° C
deposition temperature: 250° - 300° C
0.18 A/ cycle (saturated dose at 300° C)
refractive index 1.72 - 1.74
"OpAL" for
Atomic Layer Deposition
based on the Plasmalab
80 Plus
|
ALD schematic
valve between remote ICP source
and chamber,
spectroscopic ellipsometry optional |
Why remote plasma ALD ?
A "remote plasma" makes sure, the substrates
are NOT in contact with the plasma !
The remote plasma just cracks molecules,
so that very reactive species can be used
for the growth process.
Such reactive species often enable a very
efficient plasma preclean of the substrates,
lead to cleaner films and lower the deposition
temperature.
Self limiting behaviour and linear growth
regime with nucleation delay, Thickness
measured by spectroscopic ellipsometry
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