Carrier concentration profiles in multiply implanted silicon with 0.5–7.5 MeV phosphorus

Abstract

MeV implantation is very important in fabricating semiconductor devices and VLSI. The carrier concentration profiles in high energy phosphorus implanted silicon have been investigated. Phosphorus with energies ranging from 0.5 to 7.5 MeV were implanted into Si with doses ranging from 2 × 10 12 to 1 × 10 13/cm 2. The results indicate that carrier concentration profiles consist of two half-Gaussians distribution with different stragglings σ f and σ b. According to these profiles the method of forming a uniform profile with multiple implantations was suggested. The various specific carrier concentration profiles can be got by multiple implantations with different energies, doses and masking technology with SiO 2. Rapid thermal annealing has been used to obtain good reliability and reproducibility of their profiles. The residual defects of the samples were measured by 1000 kV TEM. Specific transistors produced with phosphorus multiple implantations have satisfactory characteristics.