Physico-Chemical nanomaterials science

Radiative and magnetically stimulated evolution of nanostructure complexes in silicon surface layers
D.P. Slobodzyan, M.O. Kushlyk, B.V. Pavlyk
Department of Sensor and Semiconductor Electronics, Ivan Franko National University of Lviv, 79017, 107 Hen. Tarnavskoho Str., Lviv, Ukraine. 
Е-mail: dmytro.slobodzyan@lnu.edu.ua

The problem of longterm operation of semiconductor devices and stability of their parameters in electromagnetic fields is closely related to the issue of the evolution of nanostructure complexes in surface layer of silicon crystals and base components fabricated on their basis. 
P-type Cz-Si with ρ = 10 ohm•cm resistivity was used for the studies. Samples have been cut from a single crystal silicon disk with flat surfaces orientation (111). 
The aim of the work was to form a surface-barrier structure (SBS) Bi-Si-Al and to investigate the change in their electro physical characteristics under the influence of X-radiation.
Irradiation of samples was carried out with X-ray tube (V = 45 kV, I = 8 mA, W-anode).
Magnetic field was applied with different duration and constant induction of 0.17 T.
Electrophysical properties of SBS were studied by measuring and analysing current-voltage characteristic (IVC) and high-frequency capacitance-voltage characteristic (CVC) curves. From experimental C-V characteristics, the distribution of surface-state density in silicon’s bandgap on the boundary of Si-SiO2 was calculated.
Changes of the defect structure of silicon p-type crystal surface layer under the influence X-radiation were investigated by the methods of deep levels capacitance-modulation spectroscopy (DLCMS).
Defect formation processes on the surface and subsurface layers of silicon crystals were analysed by IR spectroscopy.
Analysis of the DLCMS spectra showed evolution of clusters of interstitial silicon atoms (SiI + SiI) and formation of new point defects (BI).
300 hours exposure of single-crystal silicon samples in a magnetic field stimulates the decay of hydrogen-containing and oxygen-containing surface complexes (С-HX, Si-O-H, О-Н) and the formation of Si-H3 centers.