SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREFOR

PROBLEM TO BE SOLVED: To cancel the problem that impurities are not doped to the sufficient region of a collector layer, high-frequency characteristics are reduced due to Kirk's effect, and parasitic capacity that is generated between a base and a collector is increased when SIC implantation is made to the entire surface of the collector layer since the SIC (selectively ion-implanted collector) implantation is vertically carried out to the surface of the collector layer from the opening section of the base in a manufacturing method of the conventional HBTs (hetero bipolar transistors). SOLUTION: If SIC implantation is made from a slanting position when the SIC implantation is carried out from a base opening section 118, the SIC implantation is not made to the entire surface of a collector layer 108, the parasitic capacity that is generated between a base and a collector can be reduced, a collector implantation region 125 is extended at the lower portion of the collector layer 108, and hence Kirk's effect is inhibited, thus improving high-frequency characteristics such as a cut-off frequency fT and the maximum oscillation frequency fmaxin a low-current region. COPYRIGHT: (C)2003,JPO