| 摘要 |
PURPOSE:To enable the doping of semiconductor substrates with atoms required for doping, by a method wherein ions resulting from the combination of atoms required for doping with atoms which do not affect on the electric character istics of semiconductor substrates are implanted to the substrate surface as the ion seed. CONSTITUTION:The mass of ions required for implantation is made different from that unnecessary ions liable to mix in by utilizing the combination of dopant atoms required for doping with other atoms as the ion seed, and ion implantation is carried out by the mass separation of unnecessary ions liable to mix in. For example, in the case of Si ion implantation with the raw material of monosilane SiH4, the ions with a mass number 28 include residual gases CO<+> and N<+>2 besides Si<28+>. On the other hand, SiH<+> and SiH<+>2 are possible as the ions with mass numbers 29 and 30. SiH<+> and SiH<+>2 come not to affect on the electric characteristic of doped regions by the separation of Si from H on heat treatment and by H disappearance out of the wafer. Then, implantation of the ions with mass number 29 or 30 can yield the electric characteristics equal to those of Si ions with a mass number 28. |
