Decay of Impurity Clusters of Nickel and Cobalt Atoms in Silicon under the Influence of Pressure

Authors N.A. Turgunov, E.Kh. Berkinov, D.Kh. Mamajonova

Research Institute of Physics of Semiconductors and Microelectronics at the National University of Uzbekistan, 20, Yangi Almazar St., 100057 Tashkent, Republic of Uzbekistan

Issue Volume 13, Year 2021, Number 5
Dates Received 10 June 2021; revised manuscript received 20 October 2021; published online 25 October 2021
Citation N.A. Turgunov, E.Kh. Berkinov, D.Kh. Mamajonova, J. Nano- Electron. Phys. 13 No 5, 05006 (2021)
PACS Number(s) 61.72. – y
Keywords Pressure (12) , Silicon (58) , Nickel (7) , Cobalt (6) , Resistivity (11) , Decay of clusters.

The effect of all-round hydrostatic pressure (ARHP) on the electrophysical properties of silicon single crystals doped with nickel and cobalt has been studied. After high-temperature diffusion doping in the bulk of n-Si and n-Si samples, accumulations of impurity nickel and cobalt atoms were found. Micrographs of impurity accumulations were obtained by the method of electron probe microanalysis and their structural forms were determined. Depending on their size and shape, these impurity clusters have a single-layer or multilayer structure. Under the influence of ARHP, no significant changes are observed in the value of the resistivity of the initial samples. In contrast to them, in silicon samples doped with nickel or cobalt, under the influence of pressure, the resistivity increases significantly. It was revealed that under the influence of ARHP in the range P = 108-1.6×109 Pa, impurity accumulations of nickel and cobalt in silicon decompose, which leads to an increase in the resistivity of the samples by several times. Comparative analyzes of the morphological parameters of impurity accumulations before and after exposure to ARHP revealed that the process of decay of these clusters occurs in a certain sequence and depends on their size and shape. In n-Si samples, initially, under the influence of ARHP at P = 6×108 Pa, the disintegration of impurity clusters up to 1 mm in size, having needle-like and disc-like shapes, was observed. And in samples of n-Si under the influence of ARHP at P = 4×108 Pa, disintegration of needle-shaped and disc-shaped impurity clusters up to 0.5 mm in size was observed. Then, at higher ARHP values (Р ³ 8×108 Pa), decomposition of impurity accumulations of nickel and cobalt with relatively large dimensions, which have a lenticular and spherical shape, was found.

List of References