ISSN 10637397, Russian Microelectronics, 2011, Vol. 40, No. 7, pp. 469–472. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © A.A. Golishnikov, M.G. Putrya, E.N. Rybachek, 2011, published in Izvestiya Vysshikh Uchebnykh Zavedenii. Elektronika, 2011, No. 1, pp. 35–39.
Advances in nanotechnology have made it possible
to develop different sensors, where unique properties
of nanoscale structures are used. For instance, ultra
sensitive sensors based on nanowire silicon field effect
transistors (SiNW FETs) for detecting DNA mole
cules, proteins, pH values of solutions, and chemical
compounds can be constructed [1, 2]. Nanoscale
mechanical devices may be used for ultrasensitive
detecting of adsorbed mass, e.g., in atom mass sensors
It is obvious that nanostructure formation requires
expensive appropriate process equipment. In recent
years unconventional methods, such as AFM, nano
imprinting, or combined methods based on photolito
graphy with feature size of 1–1.5
m followed by iso
tropic etching have been widely used to produce
nanoscale elements .
This paper presents results of research and develop
ment of an isotropic plasma etching process of polysil
icon to form nanoscale structures.
To perform dry isotropic etching of a polycrystalline
silicon layer it is necessary to provide certain conditions
for the plasma chemical etching process. First, one
should use plasma sources with a high density of neutral
chemically active particles (CAPs) with minimal influ
ence of the charged plasma component on the substrate
surface. Second, reaction gases with a high yield of flu
orine radicals, such as sulfur hexafluoride and NF
must be used. Third, the etching process requires high
working pressures about 1 Torr and more .
In this work, production plasma etching system
08PE125/50008 with individual wafer processing
was employed. Fig. 1 shows the schematic view of the
Since reaction gases with high yield of fluorine rad
icals are needed to provide isotropic etching, we used
sulfur hexafluoride SF
as the working gas.
Experiments were carried out in the pressure range
from 25 to 65 Pa, with the highfrequency (HF) gen
varying from 65 to 130 W; and sulfur hexaflu
Nanoscale Structure Formation by Plasma Etching
A. A. Golishnikov, M. G. Putrya, and E. N. Rybachek
Moscow State Institute of Electronic Technology (Technical University), Zelenograd, Moscow, 124498 Russia
—Process of isotropic plasma etching of polysilicon to form nanostructures has been developed and
optimized. Dependences of the technological characteristics of the isotropic plasma etching process of pol
ysilicon on its operational parameters have been obtained. The results were to form nanowire silicon field
effect transistors and a sensitive vibroresonant nanoelement for an atom mass sensor.
Schematic view of the plasma reactor:
to the pumpingout system;