What is 4H in SiC?

4H-SiC consists of an equal number of cubic and hexagonal bonds with a stacking sequences of ABCB. 6H-SiC is composed of two-thirds cubic bonds and one-third hexagonal bonds with a stacking sequences of ABCACB. The overall symmetry is hexagonal for both polytypes, despite the cubic bonds which are present in each.

What is poly SiC?

Polycrystalline silicon carbide (poly-SiC) films have been deposited on polysilicon-coated, 4-inch silicon wafers in an atmospheric pressure chemical vapor deposition (APCVD) reactor using parameters similar to those developed by our group for single crystal SiC growth.

What is the stacking sequence of Si crystals?

stacking sequence is denoted as 2H-SiC, indicating its two-bilayer stacking periodicity and hexagonal symmetry. This periodicity doubles and triples in 4H- and 6H-SiC polytypes.

Which is better 2H sic or 3C sic?

3C-SiC has the highest electron mobility and saturation velocity because of reduced phonon scattering resulting from the higher symmetry. The band gaps differ widely among the polytypes ranging from 2.3 eV for 3C-SiC to 3 eV in 6H SiC to 3.3 eV for 2H-SiC.

How many lattice constants are there in a cubic structure?

The lattice constant, or lattice parameter, refers to the physical dimension of unit cells in a crystal lattice. Lattices in three dimensions generally have three lattice constants, referred to as a, b, and c. However, in the special case of cubic crystal structures, all of the constants are equal and we only refer to a.

Which is the only cubic polytype of sic?

All symbols in the SiC structures have a specific meaning: The number 3 in 3C-SiC refers to the three-bilayer periodicity of the stacking (ABC) and the letter C denotes the cubic symmetry of the crystal. 3C-SiC is the only possible cubic polytype.

Is the lattice constant of a diamond equilateral?

However, the full set of lattice parameters consist of the three lattice constants and the three angles between them. For example, the lattice constant for diamond is a = 3.57 Å at 300 K. The structure is equilateral although its actual shape cannot be determined from only the lattice constant.