| 摘要 |
PURPOSE:To prevent a deposit from adhering to the thin-film growth layer of a substrate even when the deposit adhering to the inner wall of a reaction tube is exfoliated in such a way that the substrate to be processed is mounted on a susceptor with its thin-film growth surface faced downward. CONSTITUTION:At a quartz reaction tube 1, a gas inlet 5 of a reaction gas 7a is installed on both sides at the lower part, and a gas outlet 6 of an exhaust gas 7b is installed in the central part at the upper part; a wafer susceptor 2 is installed in a downward-facing manner; at the susceptor 2 a recessed part 2a for mounting a substrate is formed at the downward-facing circumference, and an opening 2b, for sucking use, connected to an external vacuum source is formed; a GaAs substrate 3 to be processed is mounted on the recessed part 2a in such a way that the thin-film growth surface of the substrate 3 faces the gas inlet installed at the lower part. A deposit 8 adheres to the region which ranges from the side of the gas inlet 5 at the lower part to the part facing the susceptor 2. Because the substrate 3 to be processed is mounted at the recessed part with its surface faced downward, the deposit 8 does not adhere to the thin-film growth surface of the substrate 3 even when the deposit 8 is exfoliated by the thermal shock or the like.
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