| 摘要 |
PROBLEM TO BE SOLVED: To obtain a diffusion tube supporting heat insulating material, improved in the workability of the same upon removing the same from a diffusion furnace as well as in the yield of semi-conductor products and not generating dust from the surface of the same. SOLUTION: In a heat insulating material for supporting a diffusion tube in a diffusion furnace, the surface of the heat insulating material constituting body is covered by the long fibers of ceramics, whose alumina constituent constituting ratio is higher than 50% and which is not containing borax constituent, while the heat insulating material is preferably sewed by a sewing thread consisting of the long fibers of alumina having the same chemical constituents. In this case, an annular handle of tape type or thread type, which is constituted of the long fibers of alumina having the same constituents as the heat insulating material, is attached through the doughnut type opening thereof. |
