Abstract: A method of manufacturing a semiconductor device includes a step of forming a film doped with an emitter impurity on a predetermined surface area of a semiconductor layer. An ion implantation blocking layer is formed to cover the top and side surfaces of the doped film and the exposed surface of the semiconductor layer. Then, the blocking layer is anisotropically etched by irradiating it with a dry etchant in a direction substantially normal to the semiconductor layer. The anisotropic etching is carried out until the top surface of the doped film is substantially exposed, thereby allowing a portion of the blocking layer to leave surrounding the doped film and also substantially forming a base contact hole defined by the exposed side surface of the remaining blocking layer.