PURPOSE: To grow a thin active layer with excellent reproducibility by growing an N-GaAs current blocking layer on a P-GaAs substrate, to which a mesa in height of 2μm or more is formed, as the mesa shape of the substrate is kept as it is through an MOCVD method or an MBE method and etching only an opening section for the current blocking layer.
CONSTITUTION: A mesa in height of 5μm is shaped onto a P-GaAs substrate. An N-GaAs current blocking layer is grown on the substrate, to which the mesa is formed, through an MOCVD method or an MBE method so as to keep the shape of the mesa. Growing film thickness is brought to 1.5μm. An opening is shaped to the current blocking layer in the upper section of the mesa through etching so as to reach the P-GaAs substrate. The opening is 5μm wide. Double hetero-structure is grown on the wafer through an LPE method. The growth rate of an active layer is decreased by such a process, thus improving the controllability of the film thickness of the active layer.