METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a method of manufacturing a semiconductor device which can form an impurity diffusion region by making small a depth from a substrate surface even if a setting of implantation conditions of an ion implantation device is not changed. SOLUTION: Upon manufacturing a bipolar transistor, a SOI substrate 1 is prepared which comprises a base wafer 2, a SiO2film 3, an n+-type layer 4, and an n-type layer 5. After a base region 6 is formed on the surface of the n-type layer 5, an emitter region 6 is formed by ion implantation and heat treatment. At this time, the ion implantation is carried out on the surface of the substrate 1 by using a mask 22 having a plurality of openings 21 which are disposed at a position facing one region which is scheduled to form an emitter on the substrate 1, have all the same shape and same area, and separated from each other. Thus, the one emitter area 6 is formed. COPYRIGHT: (C)2007,JPO&INPIT