Nanocomposites and nanomaterials

Electrical conductivity of silicon oxide films with Si and Fe nanoclusters

Kizjak A.Yu.1, Evtukh A.A.1, Bratus’ O.L.1, Ievtukh V.A.1, Fedotov A.K.2

1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, Kyiv, Ukraine. E-mail: anatoliy.evtukh@gmail.com
2 Belarusian State University, 4 Nezavisimosti ave , Minsk 220030, Belarussia. E-mail: fedotov@bsu.by.

The study of the physical properties of nanocomposites films containing semiconductor and/or metal nanocrystals is important for perspective of various applications including electronics, optoelectronics, medicine, etc. For example, the problem of modern integrated microelectronics is the development of technology for the formation of electrical elements that play the role of the inductances and capacitances. One of the solutions to this problem is the use of metal-nonmetal nanocomposite materials. Accordingly, it is necessary in such cases to study the electrical properties of such structures.
In this paper, we studied the mechanisms of electrical conductivity of composite silicon oxide based films Si (silicon) and iron (Fe) nanoparticles. 
The silicon enriched SiOX (x  1.6-1.7) films containing Fe inclusions were deposited on Si wafer by ion-plasma sputtering technique. At deposition of SiOX films the cosputtering of Si and Fe targets with ratio of the areas of these targets 1:4 in an atmosphere of argon and oxygen was used. Then, during the high-temperature annealing at T=1100°C the iron and silicon nanoparticles were formed in these structures. To determine the parameters of the films (refractive index, thickness) and analysis of the mechanisms of electrical conductivity the spectral ellipsometry and current-voltage (I-V) characteristics at various temperatures from 90 to 350K methods were used.
The electrical conductivity mechanism of composite SiOX(Si,Fe) films with inclusions of iron and silicon depends on the measurement temperature. According to electron transport mechanism three temperature ranges:  (90-190К),  (190-260К) and  (260-350К) can be separated. The dependence of electrical conductivity on voltage (electric field) in each temperature range may be similar or different. For example, at low voltages ( 0.5 - 2V), the behavior of the I–V characteristics curves is similar, and at high voltages, the mechanisms of conductivity differ.
This work was supported in part by the Ministry of Science and Education of Ukraine under joint Belorussia-Ukraine Project M/21-2018.