3C005High resistivity materials as follows:

a. Silicon carbide (SiC), gallium nitride (GaN), aluminium nitride (AlN), aluminium gallium nitride (AlGaN), gallium oxide (Ga2O3) or diamond semiconductor "substrates", or ingots, boules, or other preforms of those materials, having resistivities greater than 10 000 ohm-cm at 20 °C;
b. Polycrystalline "substrates" or polycrystalline ceramic "substrates", having resistivities greater than 10 000 ohm-cm at 20 °C and having at least one non-epitaxial single-crystal layer of silicon (Si), silicon carbide (SiC), gallium nitride (GaN), aluminium nitride (AlN), aluminium gallium nitride (AlGaN), gallium oxide (Ga2O3) or diamond on the surface of the "substrate".
N.B. For materials consisting of a "substrate" specified by 3C005 with at least one epitaxial layer, see 3C001 or 3C006.