| 摘要 |
PURPOSE:To form a high quality CVD film with uniform impurity concentration and film thickness on the wafer surface by pre-heating the reaction gas because the unreacted portion is thereby reduced drastically, pressure distribution of gas generated is almost equalized and accordingly reaction can be controlled with ease. CONSTITUTION:A heater 11 for heating a furnace 10 to the specified temperature is provided in the vicinity of circumferential surface of the furnace 10 comprising an equally heated part 10a accommodating a wafer boat mounting many wafers to be processed, and at the edge of said furnace 10, a boat inserting port 10b for inserting wafer boat is provided. At the edge of furnace 10 opposing to said boat inserting port 10a, an exhaustion system 12 is provided through an exhaustion path 10c, while at the boat inserting port 10a, a gas feeding pipe 13 is provided in order to supply the reaction gas into the furnace 10. The region in the vicinity of furnace 10 of the gas feeding pipe 13 is formed spirally and a heating means 14 consisting of an induction coil 13b for preliminary heating is provided in the vicinity of circumferential surface of such spiral portion 13a. |
