ISSN 1063-7397, Russian Microelectronics, 2016, Vol. 45, No. 2, pp. 98–104. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © D.G. Gromov, S.V. Dubkov, A.A. Pavlov, S.N. Skorik, A.Yu. Trifonov, A.S. Shulyatev, Yu.P. Shaman, B.N. Rygalin, 2016, published in Mikroelektron-
ika, 2016, Vol. 45, No. 2, pp. 105–111.
Use of Thin Film of a Co
for CVD Catalytic Growth of Carbon Nanotubes
D. G. Gromov
, S. V. Dubkov
, A. A. Pavlov
, S. N. Skorik
, A. Yu. Trifonov
A. S. Shulyatev
, Yu. P. Shaman
, and B. N. Rygalin
National Research University of Electronic Technology (MIET), Zelenograd, Moscow, 124498 Russia
Institute of Nanotechnologies of Microelectronics, Russian Academy of Sciences, Moscow, 115487 Russia
NPK Technological Center, Zelenograd, Moscow, 124498 Russia
Federal State Unitary Enterprise Lukin Research Institute of Physical Problems, Zelenograd, Moscow, 124460 Russia
Received July 13, 2015
Abstract—It is shown that multiwalled carbon nanotubes can be grown on the catalytic surface of a Co–Ti–N
alloy with low (~10 at %) cobalt content by the conventional method of chemical deposition from acetylene.
Adding nitrogen to the composition of the Co–Ti contributes the formation of the TiN compound and extru-
sion of Co onto the surface where it makes a catalytic effect for CNT growth. It was found that the tubes begin
growth at a temperature of 400°C. It is shown by studies using Raman spectroscopy that the quality of CNT
improves with increasing temperature.
Carbon nanotubes (CNTs) have a whole set of inter-
esting chemical, physical, electrical, and mechanical
properties , which makes their use in various devices
such as field emission devices, flat panel displays,
X-ray generators, photonic crystals, optical wave-
guides, solar elements, sensors, fuel cells, supercapac-
itors, and lithium-ion batteries promising .
Interest in CNTs in the industry of integrated cir-
cuits (ICs) has arisen during the past decade. Increas-
ing the degree of integration and reducing the size of
an IC’s elements lead to a problem of reliability of the
multilevel interconnects in the IC, due to the increas-
ing current densities, increasing electromigration pro-
cesses in the conductors, and increasing amount of
heat generation per volume unit . CNTs are attrac-
tive as material of interconnections because they are
characterized by a very large mean free electron path
(up to several micrometers at room temperature), able
to withstand high current densities (up to 10
and highly resistant to electromigration; they also have
high thermal conductivity and conductivity at very
high frequencies .
Carbon nanotubes are produced in the electric arc
discharge between carbon electrodes or by the laser
ablation of graphite [1, 2]. However, with regard to the
IC technology, the method of catalytic chemical vapor
deposition is preferable [1, 2, 4, 5], because in this
case, CNTs grow on the surface of the solid phase. The
known catalysts for this process are Fe, Co, Ni, and Pd
metals and their alloys [6–17], as well as the alloys of
these metals with other metals, in which, however, the
content of the catalyst is always predominant [18–25].
The possibility of using a thin film of a Co–Ti alloy
with a low Co content (less than 20 at %) with the addi-
tion of nitrogen as the third component as a catalyst for
the growth of the CNTs is studied in this paper. The
appeal of using this alloy as a catalyst for CNT growth is
due to the dosing of the catalytic metal, which provides
good repeatability and uniformity of the growth process
of CNTs on the surface of the substrate, despite the prob-
ability of the dispersion of the thickness of the catalyst
film, which is crucial for IC technology.
Silicon substrates (100) coated with a layer of ther-
mal oxide were used to produce the samples. The sub-
strates were subjected to a standard washing in a
= 1 : 1 solution. Then, the substrates
were washed with deionized water and dried in an iso-
propyl alcohol vapor.
A thin film of Co
alloy was deposited by
the magnetron sputtering of the composite Co–Ti tar-
get by plasma in an atmosphere of a gas mixture of
argon and nitrogen at a residual pressure in the cham-
ber of 1 × 10
Torr and at a working gas pressure of
Torr on an unheated substrate.
Carbon nanotubes were grown by chemical vapor
deposition (CVD) using Oxford Instruments’ Plas-