Epitaxial Silicon Carbide on Silicon. Method of Coordinated Substitution of Atoms (A Review)

A review of advances in the growth of SiC epitaxial films on silicon is presented. All the main classical methods used at present to grow SiC films on silicon are described. Their advantages and disadvantages are analyzed. The main idea and theory of a new method of synthesizing epitaxial SiC films on silicon are presented. The method is called the method of coordinated substitution of atoms. In the course of coordinated substitution of atoms, the initial lattice of a silicon material with the lattice parameter of 0.543 nm “collapses” into a cubic SiC lattice with the parameter of 0.435 nm. A surprising feature of this method of growing SiC is that an interface layer several nanometers thick with nonstandard optical and electrical properties appears at the SiC/Si interface. The unusual properties are caused by the collapse (shrinkage) of the material with the separation of a new phase of silicon carbide from the silicon matrix. Silicon is subjected to abnormally strong compression. As a result of such shrinkage, every fifth SiC chemical bond becomes fully consistent with every fourth silicon bond, and the remaining bonds are deformed. This leads to a change in the structure of the SiC surface zones adjacent to silicon with its transformation into a “semimetal.” The epitaxy of SiC films on silicon due to the consistent substitution of carbon atoms for half of the silicon atoms in the absence of lattice mismatch dislocations ensures the high crystalline perfection of the SiC films. The review presents experimental data on the growth of a whole family of films and heterostructures of compounds of wide-gap A 3 B 5 and A 2 B 6 semiconductors. The SiC layer on silicon grown by the method of substitution of atoms is shown to be a new and very promising material for spintronics and creation of quantum computer elements.