Diffusion of Germanium from a Buried SiO2 Layer and Formation of a SiGe Phase

• Published in: Semiconductors (Woodbury, N.Y.) N.Y.), 2022-03, Vol.56 (3), p.215-222
• Main Authors: Tyschenko, I. E., Khmelnitsky, R. A., Saraykin, V. V., Volodin, V. A., Popov, V. P.
• Format: Article
• Language: English
• Subjects: Annealing; Buried structures; Diffusion coefficient; Diffusion layers; Germanium; Ion migration; Magnetic Materials; Magnetism; Physics; Physics and Astronomy; Silicon dioxide; Silicon germanides; SOI (semiconductors); Thickness
• ISSN: 1063-7826; 1090-6479
• DOI: 10.1134/S1063782622020154

— Ge diffusivity from a buried SiO 2 layer of a silicon-on-insulator (SOI) structure has been studied as a function of annealing temperature. It has been shown that, at an annealing temperature lower than 900°C, almost all Ge is localized in the implantation region of the SiO 2 layer. As the annealing temperature is raised to 1100°C, migration of ion-implanted Ge is accompanied by several processes: diffusion into SiO 2 , accumulation at Si/SiO 2 interfaces, diffusion into silicon, and evaporation from silicon. At 1100°C, Ge diffuses from SiO 2 to the bonding interface of the SOI structure with the diffusion coefficient of ~2 × 10 −15  cm 2 /s, which is 2 orders of magnitude higher than its equilibrium value. Depending on the thickness of the silicon layer, formation of a Ge or SiGe phase is detected after annealing at a temperature of 1100°C.