| 摘要 |
PURPOSE:To make it possible to perform uniform heat treatment, which is not affected by inputting and outputting speeds of wafers into and out of a wafer heating furnace, processing quantity of the wafers, the shapes of the wafers and the like, by heating the heating furnace to a temperature, which is lower than a temperature required for a specified heat treatment, inserting a plurality of the wafers, and increasing the temperature to the value required for the specified heat treatment of the heating furnace after the temperature in the heating furnace has been approximately stabilized. CONSTITUTION:A temperature in a furnace is made to be a temperature T1, which is lower than an oxidizing or diffusing temperature T2. Wafers are inserted in the furnace at a time point A. The temperature T1 in the furnace is fluctuated for some time period by the effect of the wafer insertion. Since this temperature is lower than oxidizing or diffusing temperature, no effect is imparted. At a specified time point ts, i.e., at a time point when the inserted semiconductor wafers are heated and the temperature in the furnace is approximately stabilized, the temperature in the furnace is increased to T2. The oxidizing or diffusing temperature is maintained for a specified time period. When the oxidization or diffusion is finished, the wafers are taken out of the furnace. Thus the specified oxidization or diffusion can be performed. |
