| 摘要 |
PURPOSE:To prevent the decrease in the degree of carrier density on the surface of boundary and to make uniform the carrier density in depthwise direction by a method wherein, after the first epitaxial crystal growth surface has been brought into a very clean state, the second epitaxial growth operation is performed thereon. CONSTITUTION:An epitaxial growth layer is formed in a thickness which is several 100Angstrom or thereabout thicker than the desired thickness on a semiconductor wafer using the method of molecular beam epitaxy, vapor phase epitaxy, liquid phase epitaxy and the like. Then, various kinds of processes of manufacturing the device are performed. Subsequently, said epitaxial growth layer is introduced into a molecular beam crystal growth device. This device consists of a substrate introducing chamber 4, a gas etching chamber 3, an exhaust preparatory chamber 2, a molecular beam crystal growth chamber 1 and the like, these chambers are provided with an independent vacuum evacuating device respectively, and each vacuum chamber is partitioned by vacuum valves 5, 14 and 16. The semiconductor wafer is heated up to a suitable temperature in the gasetching chamber 3, and the surface layer of the wafer is etched by applying etching gas. After the surface of the wafer has been cleaned, a desired molecular beam crystal growth is performed.
|
