LTG:GaAs is GaAs grown by MBE (molecular beam epitaxy) at a low temperature of 250-300
This material shows many interesting electronic properties which have been
attributed to the ~1-2% excess arsenic.
The excess arsenic results in a high concentration (~1x1020 /cm3) of point
defects, primarily as arsenic antisite defects.
The consequence of the arsenic antisite defects is the introduction of a band of
states located within the GaAs band gap.
These states prevent the GaAs surface from rapidly oxidizing and assist
- A slide about LTG:GaAs
When LTG:GaAs is annealed at 600-800 oC, the excess arsenic forms
arsenic precipitates with diameters of 5-15 nm.
The mechanism of current conduction through the annealed LTG:GaAs is
explained by a Schottky-type barrier model of arsenic precipitates.
Conductivity is determined by the overlap of depletion regions around arsenic
Last modified: July 21, 1999