After the epitaxial growth of a first semiconductor layer on a semiconductor substrate, an insulating film structure is formed on the layer. Sections of the first semiconductor layer are removed by wet etching, using the insulating film structure as a mask in order to maintain a land with a reversed mesa shape. Then opposite end sections of the insulating film structure are etched away to match the insulating film structure to the width of the land. Then a second semiconductor layer is epitaxially grown on opposite sides of the land, and a third semiconductor layer is epitaxially grown on the land and the second semiconductor layer.
