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Single crystal silicon has been grown epitaxially on a number of single crystal oxide substrates by chemical vapor deposition techniques. Such growth has been obtained in large area single crystal form on α-alumina, spinel, and beryllia. The distinct orientation relationships between the silicon deposits and a multiplicity of crystallographic planes of the various insulating substrates are indicated. Compatible with the earlier observed growths of single crystal tungsten on α-alumina, a model which assumes a fit between the silicon and the metal ion sites in the oxide substrate can account for all the epitaxial geometries. A concept of multiple fits in the metal-oxide system in terms of integral lattice parameter values as a guide in substrate selection is suggested. Representative electronic properties of the films and model fabricated devices, as well as a measure of their consequence in microelectronics, are given.

Epitaxial silicon films deposited on foreign substrates by conventional chemical deposition techniques always exhibited structural imperfections due to the lattice mismatch or the occurrence of more than one epitaxial orientation. To improve the structural perfection of these films, a moving deposition-zone technique was used to control the nucleation and growth of silicon films on hexagonal silicon carbide substrates. This technique was found to be capable of promoting the growth of silicon films of a {110} orientation with considerably increased crystal size.

Effects of temperature and time on the process of sublimation of silicon carbide were studied. Single crystals of hexagonal α-SiC obtained were transparent, light-green, up to 13 mm in size. Conductivity was of the n-type, with resistivities 102–103 ω cm.

Epitaxial layers of pure and boron-doped silicon carbide were obtained on n-type α-SiC crystals by sublimation at temperatures ranging from 2200 to 2600 °C. It was found that the layers exhibited characteristic morphological features which depended upon surface type (carbon or silicon), process temperature, and the presence of boron impurities. The rate of growth of the layers was determined at specified process conditions. Microscopic pictures of the morphological structure of layers obtained in the whole applied temperature range are presented.

Highly adherent films of cubic β-silicon carbide have been grown on single-crystal silicon substrates by heating in the presence of graphite in an argon atmosphere. The reaction process and film characteristics were investigated by electron diffraction. Initially, a single-crystal β-silicon carbide film is formed, having an epitaxial relationship to the silicon substrate. Growth proceeds by diffusion of a carbon-bearing species, from the gas phase, inward to the silicon-silicon carbide interface. Beyond a certain thickness, growth becomes polycrystalline. Both n - and p -type films resulted from spontaneous doping, but high resistivities were not observed.

Metallographic and electron microscopic examination of defects in silicon epitaxial films, grown on silicon wafers on graphite heaters, disclose the origin and characteristics of ``faults'' and tetrahedral growths. The occurrence of ``snowstorm'' spheres has also been investigated. Silicon carbide has been identified epitaxial on (111) substrates etched in hydrogen. The carbide grows as thin needles against the {112} step risers of the [111] zone. The steps appear to be formed during the room temperature oxidation of the silicon wafer surface prior to hydrogen etch. The ``faults'' are shown to be twin lamellae resulting from overgrowth of the carbide by the silicon. The methane transport reaction is proposed as the cause of carbide formation. Tetrahedral growths are shown to result from silicon nucleating directly on the carbide away from surface steps. They are twinned to the substrate, and grow faster than the adjacent epitaxial film. Their growth morphology is discussed. The spheres are polycrystalli...

Crystal growth of 2H silicon carbide showing temperature profile along susceptor as affecting factor

Beta silicon carbide has been grown epitaxially on silicon, sapphire and silicon carbide substrates by chemical conversion, cathodic sputtering and a combination of both. The structural properties of the silicon carbide are described as a function of formation conditions. The applicability of the conversion technique to the epitaxial growth of β-silicon carbide on insulating substrates such as sapphire is discussed. Results show that thick epitaxial films of β-silicon carbide can be grown by using chemical conversion followed by cathodic sputtering.

Silicon carbide was generated by pyrolysis of gas mixtures consisting of silicon tetrachloride, hydrogen, and organic vapors, such as acetone, on fine tungsten wires resistance-heated at 1500°C. Prominent two-dimensional structure was demonstrated for the 220 reflection. All other lines were of the normal three-dimensional lattice type.

Silicon carbide single crystal growth using the Norton Process is described. The influence of growth temperature and temperature gradients in the growth furnace are determined. The electron hall mobility of nitrogen doped crystals is measured as a function of the nitrogen concentration in the silicon carbide crystals. A new mechanism of silicon carbide crystal growth is postulated that involves a v-1-s approach.

Thin single‐crystal films of cubic silicon carbide have been grown on silicon substrates within the temperature range 800‐ 1000°C in high and ultrahigh vacuum by the reaction of unsaturated hydrocarbons, C2H and C2H4 with silicon. The cubic silicon carbide grows with a parallel orientation onto silicon, regardless of crystal orientation. The use of ultrahigh vacuum results in high crystal perfection.

IT is well known that silicon carbide forms a great variety of polytypes. The significance of these polytypes is so far not fully understood, although the known types appear to be consistent with the theory postulated by Ramsdell and Kohn1 according to which : “Each polymer is characterised by a particular temperature stability range. At a given characteristic temperature a single type of polymer would produce a ‘pure type’ …. If stability ranges overlap two polymers might exist simultaneously resulting in a ‘mixed type’”.

Silicon carbide crystals are commonly grown from the vapor at a temperature of about 2600°C in so called "sublimation" furnaces wherein crystals are grown on the inside walls of a cavity formed within a large porous block of silicon carbide. A model for growth in this system is postulated and growth rate as a function of temperature is calculated. Growth in argon with pulses of nitrogen introduced at regular (7½ min) intervals is shown to produce sharp green lines that define the successive crystal sizes during the entire growth period (~8 hr). Temperature changes are made during growth and the growth rates are measured during successive temperature cycles. Considerable fluctuation in growth rate is revealed by this new measuring procedure. Theory and experiment are in qualitative agreement.

The traverse X-ray diffraction micrography is applied to studies on silicon carbide single crystals of 6H structure. Two kinds of dislocations of new types, having the Burgers vector in a direction and in an average direction , are found. The second kind of dislocation is often found in distorted regions of the crystals and sometimes created by chopping or neutron irradiation. Impurity layers which are proved to exist seem to be a cause of the lattice distortion. The mechanism of crystal growth is discussed in relation to the second kind of dislocation.