| 摘要 |
PURPOSE:To suppress the diffusion of an emitter region by a method wherein the oxygen gas concentration in an atmosphere is reduced when a diffusion process is performed on a main conductor substrate made of heavy metal. CONSTITUTION:A P type base region 3 is formed on an N<-> type collector region which was formed on a P type main conductor substrate 1, and a transistor structure is obtained by forming an N<+> type emitter region 4 on the P type base region 3. Then, after gold layer 8 has been formed by evaporation on the reverse side of the P type semiconductor substrate 1, gold is diffused in the semiconductor substrate by performing a heat treatment in the mixed gas atmosphere of oxygen gas and nitride gas. The diffusion of the emitter region 4 which is carried out by the heat treatment is suppressed in proportion to the decrease of percentage of the oxygen gas contained in the mixed gas, and by bringing the oxygen gas concentration below 10%, the diffusion of the emitter region 4 can be suppressed sufficiently. |
