Abstract :
b-FeSi2 quantum dots (QD) were grown by evaporating 2, 4 and 7 nm Fe onto Si(1 0 0) wafers and in situ annealed at 600 8C
for 10 min. QDs were grown also by reactive deposition epitaxy (RDE) evaporating 2 nm Fe onto a 600 8C Si substrate and
annealed further for 5 min. MIS structures were prepared by evaporating SiOx over the QDs and Al dots on the oxide. The SEM
investigations show the density of the QDs is about 1010 cm 2 in the 2 and 4 nm Fe samples, and it increases to about
3 1011 cm 2 in the 7 nm Fe sample. The nanoscope investigation shows well resolved QDs only in the 7 nm Fe samples, but
their density and size do not allow individual characterization of the QDs by scanning capacitance microscopic measurements.
In the RDE samples the QDs are small and irregular, indicating the need for thicker Fe layer.
Capacitance–voltage (C–V) measurements show point defects generated by silicidation which compensate the silicon doping
(2 1015 cm 3) in about 1 mm depth. C–V results show that in the RDE samples less point defect are generated, their
concentration is lower than doping of the Si wafers. The electrical characteristics of MIS structures show that the room
temperature deposited iron degrades the I–V characteristics, and induces leakage.
# 2004 Elsevier B.V. All rights reserved.
