| 摘要 |
PURPOSE:To efficiently heat-treat a wafer, by controlling the speed of a heat- treating boat in accordance with the variation of the temperature applied to the boat in a core tube. CONSTITUTION:At starting, a loader 7 rapidly inserts a boat 4 into a furnace 2. When the boat 4 reaches the boundary between temperature zones C and B, a switch 12 outputs to a controller 8 so as to slow the boat. When the boat reaches entirely in a temperature zone A, the loader is stopped by a detection signal from the switch 13. After the heat treatment, the loader operates in the reversed sequence. Since the variation of temperature distribution is gentle in the zone C and the wafer 3 is not subjected to large thermal strain there, the boat 4 can be moved rapidly in that zone. In such a manner, the period of time required for inserging and taking out the boat is reduced, and the efficiency of the heat-treating process can be improved. A temperature sensor 20 for outputting to the loader controller may be incorporated in the boat so as to realize in-line control with stable reproducibility. |
