Method of producing hetero-junction bipolar transistor

A method of producing a hetero-junction bipolar transistor includes: laminating semiconductor layers that are to be a subcollector layer, a collector layer, a base layer, an emitter layer and an emitter cap layer successively on one surface of a semi-insulating substrate; and forming an electrode layer on the emitter cap layer. The method also includes adjusting the shape of the emitter cap layer to be a predetermined shape by wet etching; and removing end portions of the electrode layer so that the edges of the electrode layer are substantially aligned to the edges of the top face of the emitter cap layer. Furthermore, the method includes removing a surface oxidized layer formed on the emitter layer. Thus, defective etching of the emitter layer including an element P of group V is resolved, and a hetero-junction bipolar transistor having predetermined properties can be produced stably.