Τίτλος:
The effect of arsenic overpressure on the structural properties GaAs
grown at low temperature
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
The structural properties of GaAs grown by molecular-beam epitaxy at low
temperatures have been investigated by scanning electron microscopy,
transmission electron microscopy, and high-resolution x-ray
double-crystal rocking curves as a function of arsenic overpressure
during growth. It was found that surface smoothness and excess arsenic
incorporation both depend strongly on growth temperature and on As/Ga
flux ratio, For each growth temperature there is a ‘’window” in the
flux ratio which results in smooth surfaces. As-grown layers have an
increased lattice constant in the growth direction. This relative
lattice expansion increases with flux ratio at a constant growth
temperature and eventually saturates, Transmission electron micrographs
have revealed the presence of arsenic precipitates in material annealed
at 600 degrees C. Increasing the As-4 pressure during growth results in
increases in precipitate diameter by almost 50% while their density and
shape remain constant. Based on these observations a model has been
developed to explain the lattice expansion dependence on arsenic
overpressure. (C) 1996 American institute of Physics.
Συγγραφείς:
Lagadas, M
Hatzopoulos, Z
Tsagaraki, K
Calamiotou, M and
Lioutas, C
Christou, A
Περιοδικό:
Journal of applied physics
Εκδότης:
AMER INST PHYSICS
