| 摘要 |
PURPOSE:To prevent the releasing of heat from a core pipe, and to save power and increase soaking length by placing a wafer basket hung by a stick on a stage for heat insulation mounted on the bottom of the core pipe, retreating the stick outside the core pipe and thermally treating a wafer. CONSTITUTION:A basket 15 is lowered by using a stick 16 and placed on a stage 18. The stick 16 is turned and disengaged from a connecting state with the basket, and retreated outside a core pipe 11, and wafers are diffused and thermally treated in a predetermined manner. Consequently, the downward escape of heat is prevented by the stage 18 for heat insulation, and power consumption is reduced with the prevention of the releasing of heat. All of the wafers 17 in the basket 15 are diffused and thermally treated uniformly because soaking length determined by the geometric size of a heater 12 is increased. Since the stick 16 is retreated outside the core pipe during heat treatment, the basket 15 is placed only on the stage 18 even in heat treatment at a high temperature of 1,100 deg.C or higher, thus completely preventing the damage of the basket and the wafers due to the elongation or cutting of the stick 16. |
