MANUFACTURE OF HEAVILY DOPED SEMICONDUCTOR SUBSTANCE

摘要

PURPOSE: To provide a method of diffusing/doping a semiconductor chip and wafer, especially a silicon chip and a wafer in the peak concentration exceeding a specific temperature. CONSTITUTION: A semiconductor material to be doped is placed in a furnace 57. The atmosphere in the furnace contains carrier gas 20 and dopant-containing gas 22. The dopant-containing gas exceeds about 0.1% of the whole capacity in the furnace chamber. The mixed gas pressure exceeds about 0.1 Torr while the mixed gas contains an oxidant at concentration not exceeding about 1 ppm. Thus, a shallow doping region in high peak concentration can be formed by the diffusion process by directly doping the silicon surface so that the damage to the silicon surface by ordinary ion implantation for securing the high doping concentration may be prevented. In such a constitution, a trench sidewall can be doped at high concentration by this nondirectional method.