| 摘要 |
PURPOSE:To improve a temperature distribution of a substrate, by moving a semiconductor substrate on a mounting board up and down by the use of at least three supporting rods (pins), to minimize a part of the substrate in no contact with the mounting board. CONSTITUTION:Rotating a pulse motor 23 makes three driven gears 21 rotate. Then, the three driven gears 21 rotate in the same direction and rotational angle because the number of their teeth are made to be equal. Rotation of the driven gears 21 is converted into motion of a male-screw unit 16 moving upward in the male 19 and female 15 parts. The male unit 16 rises rotating to push up a semiconductor substrate 24 on a susceptor 12 by the use of three thin pins 17 through small holes opened in the susceptor 12. Reverse rotation of the pulse motor 23 makes the male screw unit 16 lower to locate the semiconductor substrate 24 on the susceptor 12. And, con-current up-and-down movement with equal distances for at least three supporting rods enables the semiconductor substrate to be moved up and down without its inclining.
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