| 摘要 |
PURPOSE:To facilitate the liquid growth of GaAlAs on a thick GaAlAs epitaxial layer as well as to contrive improvement both in the yield of growth of wafers and the uniformity in quality of each element by a method wherein a Ga1-uAluAs layer or a GaAs layer having low AlAs mixed crystal ratio is formed as an oxidation- preventing film on a Ga1-xAlxAs having high AlAs mixed crystal ratio, and the oxidation-preventing film is removed by performing a meltback using a Ga solution when a double hetero growing method is performed. CONSTITUTION:A Ga1-xAlxAs epitaxial layer 2, having the thickness of 50 mum or above and the AlAs mixed crystal ratio of 0.1 or above, is formed on a GaAs substrate 1. Then, a Ga1-ualuAs epitaxial layer, having the thickness of 0.1 mum or above and the AlAs mixed crystal ratio of 0.1 mum or below on the surface, is formed on the epitaxial layer 2. After said Ga1-uAluAs epitaxial layer has been removed by meltback using a liquid growth method, Ga1-yAly As epitaxial layers 4-6 of one or more layers are formed. The composition for growth of a P-type clad layer is set at 3.8 mg for GaAs, 5.3 mg for Al and 0.6 mg for Zn against Ga 1g and a non-saturated solute state is obtained, and an undoped GaAs epitaxial layer 3 is meltbacked completely at 880 deg.C using a Ga solution. Then, a P-type Ga1-yAlyAs clad layer 4 is formed by cooling slowly. |
