| 摘要 |
PURPOSE:To obtain a super-lattice semiconductor characterized by a large area and steep composition change at an interface with good reproducibility, by turning ON and OFF the projection of optical energy so that the optical energy is not projected in growing a first thin film and the optical energy is projected in growing the second thin film, in two kinds of compound semiconductor thin films constituting a super lattice. CONSTITUTION:A constant temperature bath 120 is filled with trimethylgallium TMG, and a constant temperature bath 121 is filled with trimethylaluminum TMA. A substrate 109 is mounted on a carbon susceptor 110 and undergo induction heating to 500-800 deg.C by a high frequency power source 111. At first, a Ga0.9Al0.1As thin film is grown to 10-100Angstrom by an MOCVD method. Then, under this state, light from an ultraviolet light source 101 is directly projected on the surface of the substrate by opening an optical shutter 133. Thus, decomposition of the TMA is accelerated by the ultraviolet light, and GaAlAs having much Al composition is grown. A super-lattice semiconductor can be manufactured only by turning ON and OFF the optical energy. Therefore, steepness at an interface can be ensured, and an ideal super-lattice semiconductor can be formed.
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