| 摘要 |
PURPOSE:To grow a semiconductor crystal with a surface flattened on an atomic level by growing an AlGaAs layer on a substrate by molecular beam epitaxy, then stopping an Al beam to grow a thin GaAs layer, and then stopping even a Ga beam to transiently interrupt the growth. CONSTITUTION:An Al0.7Ga0.3As layer 2 is grown on a GaAs substrate 1 by molecular beam epitaxy. Only the Al beam is then stopped to grow a GaAs layer 3 to the extent of 1-2 atomic layers or thinner. The Ga beam is then also stopped to interrupt the growth, and the state is kept for about 1X2min. At this time, the Ga atom in excess of the surface atomic layer is diffused on the surface and forms a mixed crystal with AlGaAs, hence the content of Al in the surface atomic layer 7 is relatively reduced, the surface diffusion of the Al atom is promoted, and the crystal surface is flattened. As a result, when the Ga beam is again projected to grow the GaAs layer, the hetero-junction interface of GaAs/AlGaAS flattened at an atomic layer unit is obtained.
|
