| 摘要 |
PURPOSE:To form easily and surely a compound semiconductor layer with a desired composition ratio, by providing a source region separated from a growth region by a check valve with a purge gas supplying pipe and an exhaust pipe. CONSTITUTION:For example, in the case of forming a gallium and arsenic layer, gallium is mounted on a source stand 13 in the source region 11 of a reaction tube 1, and arsenic trichloride from a reaction gas supplying pipe 2 and hydrogen from a bypass tube 4 are supplied. The inside pressure of the region 11 is higher than that of a growth region 12, and so a check valve 5 separating the regions 11 and 12 opens to supply gallium and arsenic to the region 12. Thus, gallium and arsenic are grown in a substrate on a retainer 14. When arsenic reaches a supersaturation state and the supplying tube 2 is closed, the inside pressure of the region 11 decreases and the check valve 5 closes. As the reaction gas is not supplied to the region 12, the growth of a semiconductor stops, and a transition layer and the like are not formed. On the other hand, purge gas of low pressure is supplied through a purge gas supplying pipe 6, and the residual gas in the region 11 is discharged through an exhaust pipe 7. By this constitution, a compound semiconductor layer with a desired composition ratio can be easily and surely formed.
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