  A 2D layer of spherical, crystalline Ge nanodots embedded in SiO2 was formed
by low pressure chemical vapour deposition combined with furnace oxidation and
rapid thermal annealing. The samples were characterized structurally by using
transmission electron microscopy and rutherford back scattering spectrometry,
as well as electrically by measuring CV and IV characteristics. It was found
that formation of a high density Ge dots took place due to oxidation induced Ge
segregation. The dots are situated in the SiO2 on the average distance 5 nm
from the substrate. Strong evidence of charge storage effect in the crystalline
Ge nanodot layer is demonstrated by the hysteresis behavior of the high
frequency CV curves.
