| 摘要 |
PURPOSE:To prevent the generation of irregularity in resistance value of an epitaxial layer caused by self-admixture by a method wherein an epitaxial layer is grown on both front and back sides of a wafer simultaneously. CONSTITUTION:The hole 31 of a disc-shaped holder 3 has a placing stage 32 for a wafer 8 and an inclined surface 32 spreading toward the direction under the stage 32. A coil 4 is set at an approximate temperature of 1,150 deg.C using a high frequency power source 5, mixed gas is sent to a vacuum chamber 1, and epitaxial layers 10a and 10b are grown on both surfaces of the wafer. The epitaxial layer 10b suppresses the impurities diffusing toward outside from inside of the wafer, and a self-admixture phenomenon is also prevented. The control of thickness of the layer 10b is not important particularly. According to this constitution, the irregularity of resistance value of an epitaxial layer 8a can be eliminated easily, and the SiO2 or polysilicon film on the back side, which is necessary in convensional constitution, is unnecessitated. |
