| 摘要 |
PURPOSE:To make thickness and quality of film even in epitaxial growing process by a method wherein a control system of a shutter and a motor is provided to make a wafer turning integer times within opening period of each shutter. CONSTITUTION:The central control circuit 26 outputs shutter control signals S1 setting up opening and closing time of each shutter 6 to a shutter control circuit 24 simultaneously outputting revolution control signals S2 setting up revolution of a motor 10 synchronizing with the shutter control signals S1 to a revolution control circuit 22 according to directive signals S0. The signals S2 are set up e.g. so that integer times of the pulse cycles may be equivalent to the output period of the shutter control signals S1. When the shutter control signals S1 are inputted to the shutter control circuit 24, a specified shutter 6 is opened for specific times to supply the wafer 6 with the material as molecular beam required for epitaxial growing process from a material supply source 4. Besides, the revolution control circuit 22 controls the revolving speed of the motor 10 according to the inputted revolution control signals s2. |
