MANUFACTURE OF SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To obtain a method of manufacturing a semiconductor device, where a P+GaAs layer can be exposed surely. SOLUTION: In the manufacturing method of a semiconductor device, which includes a GaAs layer and an InGaP layer formed on the GaAs layer, a first process 1 where the InGaP layer is etched by the use of a first etching liquid and a second process 2 where InGaAsP is etched with a second etching liquid which is capable of etching it are provided. By this method, an N-type InGaAsP layer, produced by substituting As with P when a thin film is grown can be etched, so that a P+-GaAs layer can be exposed surely. Therefore, a semiconductor device of this constitution can be lessened in base resistance.