XVI Russian Conference on Semiconductor Physics, October 7-11, 2024, St. Petersburg
Semiconductors
Mechanism of growth of Ga$_2$O$_3$ epitaxial layers by hydride vapour-phase epitaxy on SiC/Si (110) substrate
S. A. Kukushkina,
A. V. Osipovb,
E. V. Ubyivovkab,
E. V. Osipovaa,
Sh. Sh. Sharofidinovc a Institute of Problems of Mechanical Engineering, Russian Academy of Sciences, St. Petersburg, Russia
b Saint Petersburg State University, St. Petersburg, Russia
c Ioffe Institute, St. Petersburg, Russia
Abstract:
The article studies the growth mechanisms of epitaxial films of
$\beta$,
$\varepsilon$ and
$\alpha$ phases of gallium oxide (Ga
$_2$O
$_3$) grown by hydride vapour-phase epitaxy(HVPE) on the surface of hybrid SiC/Si substrates synthesized by the method of coordinated atomic substitution (MCSA) on the surface (110) of silicon substrates. The growth of Ga
$_2$O
$_3$ layers occurred in a wide range of substrate temperatures from 550
$^\circ$C to 1050
$^\circ$C. The microstructure was analyzed using Raman spectroscopy and high-resolution transmission microscopy (TEM). The chemical composition (distribution of chemical elements) was determined using an X-ray spectrometer (EDS), which is an attachment to a scanning electron microscope (SEM). As a result of the studies, it was found that the growth of the Ga
$_2$O
$_3$ film on the SiC/Si (110) surface occurs in two stages. In the first stage, the SiC/Si(110) surface is enriched with carbon and saturated with silicon vacancies as a result of the interaction of chlorine, which is a product of the reaction of gallium chloride and oxygen, with the SiC/Si(110) surface. Only after the formation of a thin, approximately 1.5 nm thick, carbon layer on the SiC surface, the second stage begins, namely, the growth of the Ga
$_2$O
$_3$ layer begins. The growth of Ga
$_2$O
$_3$ begins with the introduction of oxygen atoms into the carbon layer, to which gallium atoms are then attached. After which the growth of the bulk Ga
$_2$O
$_3$ layer begins. Since the reaction between chlorine and SiC begins to occur noticeably only at temperatures above 700
$^\circ$C, then at lower temperatures no carbon layer is formed on the SiC surface, and accordingly, Ga
$_2$O
$_3$ layers do not nucleate. It has been suggested that in order to grow high-quality Ga
$_2$O
$_3$ films, the SiC surfaces must be modified before growth by covering them with either a thin carbon layer or a graphene layer.
Keywords:
silicon carbide on silicon, gallium oxide, $\alpha$-, $\varepsilon$- and $\beta$- and Ga$_2$O$_3$ polytypes, graphene, carbon nanostructures, growth mechanisms. Received: 17.11.2024
Revised: 24.11.2024
Accepted: 25.11.2024
DOI:
10.61011/FTT.2025.01.59775.309
Fulltext:
PDF file (11154 kB)