| 摘要 |
PURPOSE:To suppress growth in the vicinity of the surface to such a degree as negligible and to accurately control thickness of epitaxial layer and distribution of carrier concentration by simultaneously suspending supply of the V group element compound and introduction of carrier gas participated in supply of such carrier gas. CONSTITUTION:A GaAs substrate 4 is placed on a quartz jig 5 which is located in the down stream area in an reaction tube 1, the H2 gas 8 including the specified amount of AsCl3 6 is introduced and simultaneously the specified amount of H2S and H2 are also introduced into the reaction tube, after the gas generated by reaction with Ga2 is carried to the substrate 4 for the growth in the specified period, the valves 9, 10 are closed suspending supply of AsCl3 6. At this time, the valve 11 is closed simultaneously, and amount of H2 8 introduced is increased up to three times of that when AsCl3 is supplied in view of purging H2. Thereby the furnace body is cooled. At this time, since pressure within the introducing tube 7, Ga casing 3 becomes lower than the pressure in the vicinity of substrate 4, the gas remaining in the container 3 is substantially trapped therein, and only H2 sent from the tube 8 reaches the substrate 4. Thereby abnormal growth at the substrate surface is almost suppressed (500Angstrom or less) and thickness and carrier gas concentration distribution can be controlled accurately. |
