| 摘要 |
<p>PURPOSE:To prevent oxidation deterioration of a heating part and to lengthen life by coating a porous opening hole wall surface of the heating part of a silicon carbide heating unit with a silicon carbide coating membrane by the CVD method. CONSTITUTION:A silicon carbide heating unit 10 is formed with a heating part 1 in the middle part, low resistant parts 2 in both sides of the part 1, and terminal parts 3 in both ends. And silicon carbide coating membranes 5 are formed on the wall surface of porous opening holes 4 of the part 1. Forming membranes 5 causes the heating unit to be enclosed in a closed vessel, and the inside to be decompressed and heated to a deposition temperature of the CVD reaction. Then supplying a reaction gas causes the gas to enter into holes 4 by decompressing, and silicon carbide to be deposited on the wall surface. When pressure in the vessel reaches to over the given pressure, again decompressing is made and the gas is resupplied. Membranes 5 having a required thickness are formed on the opening hole wall surface by repeating the said operation. This enables oxidation deterioration of the heating part to be prevented, and service life lengthened.</p> |
