(3DMAS and 2DEAS have also been used)
O radicals and O2
bubbled at 35° C
dose control by fast pulse ALD valve
Good self limiting process
deposition temperature: 100° - 400° C
cycle time 9 sec (for 200 mm wafer)
(shorter for smaller substrates)
1.4 A/ cycle (saturated dose at 290° C)
9 A/ min, > 56 nm/ hr (for 200 mm wafer)
(faster for smaller substrates)
BHF wet etch rate < 100 nm/ min (300°C)
(< 150 nm/ min with 3DMAS)
uniformity: < ± 1 - 3 %
(depending on substrate size)
repeatability < ± 1 %
C < 4 % (at 400 °C)
refractive index 1.42 - 1.44
The Si:O ratio is 1:2.
Growth rate per cylce (GRC) vs
the metal precursor dose time
Growth rate per cycle vs plasma on
= radical exposure time
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
efficient plasma preclean/ conditioning of the
substrates, lead to cleaner films and lower
the deposition temperature.
In Oxford systems it is possible to
ALD processes using
- the thermal only method
- ozone assisted processes
- remote plasma assisted processes
together without any hardware change.
Multiple step processes using all technologies
can be chosen from the software.
substrate plasma preclean
plasma cleaning of the chamber
(SF6, typ 1 hour cleaning per month
Growth Rate per Cycle (GRC)
and refractive index
vs deposition temperature