| 摘要 |
PURPOSE:To grow high-purity epitaxial layer having extremely low impurity density in gas phase by a method wherein static electromagnetic field is provided in stream of reaction gas so that impurity ions likely to be mixed into growing layer is guided to the outside of substrate. CONSTITUTION:Si gas supplied from the Si source 1 is guided through pipe 2 to pipe 8, and adding-impurity from the impurity source 4 is ionized by the ionization device 5 and guided through pipe 6 to the pipe 8. Unrequired Si supply gas is discharged from the outlet 3 and unrequired ionized adding-impurity is discharged from the outlet 7. Reaction gas consisting of Si cpd gas and ionized adding-impurity gas is guided into the grow-furnace 9, where DC voltage generated by the constant voltage source 13 is applied to electrodes 11, so that impurity ions are selectively moved in the reaction tube in the furnace 9. This allows impurity ions remaining in reaction gas stream to be guided to the outside of substrate in the reaction tube, so that the effect to growing layer is eliminated. |
