Electrically conductive Si3 N4 -C series amorphous material and a method of producing the same

Claim 1

A method of producing massive and pure Si 3 N 4 -C series amorphous material composed of a deposited amorphous Si 3 N 4 matrix and codeposited carbon uniformly distributed in said matrix, having an electrical conductivity σ of a formula σ=σ.sub.o exp(-E/2kT) wherein σ o is an electrical conductivity at 0° K., E is a value of 0.02-0.06 eV, k is the Boltzmann constant and T is an absolute temperature, a carbon content of about 0.2-10% by weight, an electrical conductivity σ of about 10 -3 to 10 -1 Ω -1 cm -1 at a temperature from ambient to about 900° C., a density of about 2.7 to 3.0 g/cm 3 , a thermal conductivity of about 0.004-0.010 cal/cm·sec·K at ambient temperature, a specific heat of about 0.16 cal/g·K at ambient temperature, a thermal diffusivity of about 0.010-0.022 cm 2 /sec at ambient temperature, and a micro Vickers hardness of about 2,500-3,500 kg/mm 2 (100 g load) at ambient temperature by chemical vapor deposition process, which comprises reacting SiCl 4 as silicon source gas, a nitrogen source gas and a hydrogen source gas with a carbon source gas at a deposition condition of a deposition temperature of about 1,100° to 1,300° C. under a reduced total pressure of about 30-70 mmHg in a reaction furnace to deposit the Si 3 N 4 -C series amorphous material on a surface of a substrate selected from the group consisting of graphite, silicon carbide and silicon nitride, the substrate being heated to said deposition temperature.

Claim 2

A method of producing massive and pure Si 3 N 4 -C series amorphous material composed of a deposited amorphous Si 3 N 4 matrix and codeposited carbon uniformly distributed in said matrix, having an electrical conductivity σ of a formula σ=σ.sub.o exp(-E/2kT) wherein σ o is an electrical conductivity at 0° K., E is a value of 0.02-0.06 eV, k is the Boltzmann constant and T is an absolute temperature, a carbon content of about 0.2-10% by weight, an electrical conductivity σ of about 10 -3 to 10 -1 Ω -1 cm -1 at a temperature from ambient to about 900° C., a density of about 2.7 to 3.0 g/cm 3 , a thermal conductivity of about 0.004-0.010 cal/cm·sec·K at ambient temperature, a specific heat of about 0.16 cal/g·K at ambient temperature, a thermal diffusivity of about 0.010-0.022 cm 2 /sec at ambient temperature, and a micro Vickers hardness of about 2,500-3,500 kg/mm 2 (100 g load) at ambient temperature by chemical vapor deposition process, which comprises reacting SiCl 4 as silicon source gas, a nitrogen source gas and a hydrogen source gas with a carbon source gas at a deposition condition of a deposition temperature of about 1,100° to 1,300° C. under a reduced total pressure of about 30-70 mmHg in a reaction furnace to deposit the Si 3 N 4 -C series amorphous material on a surface of a substrate selected from the group consisting of graphite, silicon carbide and silicon nitride, the substrate being heated to said deposition temperature.