1063-7397/01/3004- $25.00 © 2001 MAIK “Nauka /Interperiodica”
Russian Microelectronics, Vol. 30, No. 4, 2001, pp. 236–242. Translated from Mikroelektronika, Vol. 30, No. 4, 2001, pp. 279–285.
Original Russian Text Copyright © 2001by Elinson.
The development of quantum-effect devices, which
are based on multiple-quantum-well (MQW) struc-
tures, is viewed as a promising avenue for the evolution
of today’s microelectronics. The disadvantages of
MQW-based devices, as well as those based on super-
lattices, are the complex fabrication technologies and
sometimes a strong effect of diffusion processes on
their thermal stability.
Another key problem in the development of micro-
electronics, nanotechnologies, and microsystems engi-
neering is the formation of good interfaces between
layers with preset properties, largely between single-
crystal bulk semiconductors and thin ﬁlms.
The aim of this work is to form nanocomposite (20–
1000 Å) carbon layers by plasma-assisted ion deposi-
tion onto the surface of a single-crystal semiconductor
and also by ion-beam modiﬁcation of the surface of
The ion-beam approach is appropriate for synthesis
of nanocomposite materials and surface modiﬁcation
because it, unlike other technologies, allows the local
delivery of high energy (100 eV or more) and can tackle
the above problems.
Amorphous hydrogenated carbon (
-C : H) ﬁlms
are known to be hard, chemically inactive, and radia-
tion-resistant. At present, they are widely used as wear-
resistant, masking, and passivating coatings in micro-
electronics and in conventional, laser, and X-ray optics.
In addition, the ﬁlms are applied as gate dielectrics in
microelectronic devices. However, the electrophysical
and optical properties of
-C : H heterostructures made
with modern technologies (see, e.g., [1–3]) make it pos-
sible to considerably extend their applications.
-C : H ﬁlm technologies allow us to vary
the properties of the ﬁlms in a wide range by changing
the phase composition, cluster size (clusters deﬁne the
dimension of short-range order in amorphous struc-
tures), and saturation of dangling bonds. This, in turn,
gives a chance to vary (by several orders of magnitude)
the density of recharging states and thus control the
properties of the interfaces. Moreover, of great impor-
tance is the unique possibility of varying the mobility
gap (the least energy of activation of interband transi-
tions) in wide limits. This opens the door to the produc-
tion of carbon-ﬁlm-based multilayer structures with
various phase compositions [3–5].
Carbon, having a variety of stable and metastable
modiﬁcations separated by high activation barriers,
allows the implementation of these structures. Carbon-
based structures offer the increased thermal stability;
hence, associated devices have a longer lifetime in
comparison with multilayer structures made of dissim-
ilar materials because of suppressed diffusion between
the layers. Next, the carbon technology involves envi-
ronmentally benign chemical operations and allows the
uniﬁcation of process steps.
The fabrication of the structures offers considerable
scope for band engineering. Since the technology of
MQW structures based on
-C : H layers is simple and
inexpensive, they are candidates for quantum-effect
To characterize quantum effects and experimentally
found properties of the amorphous MQWs, we exploit
the energy band model and apply the effective mass
approximation for free electrons and holes moving in a
one-dimensional periodic potential ﬁeld. The potential
is assumed to be similar to that in quantum-size struc-
tures with single-crystal semiconductor layers [5–7].
Artificial Potential Relief in Carbon Films
and Associated Heterostructures
V. M. Elinson
Tsiolkovskii State Institute of Aviation Technologies (Technical University), Moscow, Russia
Received February 15, 2000
—The possibility of constructing an artiﬁcial potential relief and fabricating multiple-quantum-well
(MQW) structures based on ultrathin
-C : H layers is demonstrated. The photoelectric properties of the struc-
tures are studied, the carrier transfer mechanism is established, and the inﬂuence of the applied voltage on the
carrier transfer mechanism is demonstrated. The effect of illumination on the active and reactive components
of the admittance of the structures and on the charge transient energy spectra of recharging traps and relaxation
centers is studied. The parameters of the MQW structures, such as concentration, energy position, and trapping
cross sections of deep levels; band bending at the
-C : H/Si interface; potential well depths; etc. are deter-
-C : H layers with a small trap concentration are obtained. Such layers can be used as gate dielec-
trics in MIS transistors. Single-crystal Si–
-C : H ﬁlm heterostructures can operate as photodiodes, photovar-
actors, and dynamic memory elements.