Most group V and VI elements evaporate as
unreactive polymeric species. Thermal pre-dissociation at practical
temperatures (<1500°C) results in reactive dimers, e.g: P2,
As2, Te2.
Dissociation to the most reactive atomic species, S, Sb, As, etc.,
can be achieved by passing the vapour through an intense plasma
discharge.The very high reactivity of atomic species reduces
feedstock inventory and chamber wastage. Additionally, the incorporation
of a fast-acting valve, located at the cracker head, allows rapid
control of the atomic flux over a wide dynamic range. The all-quartz
RF valved crackers from Oxford Applied Research with patented ,
field-proven
in-line control valve, integrated into our RF magnetic-multipole plasma
source (500-plus in MBE systems worldwide), provide an advanced tool for
MBE growers.
1. Calhoun, L.C. and
Park, R.M. J.App. Phys. 85,
pp 490, 1999
2.
Doping of ZnSe
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