[15p-B9-1~17] 13.3 Insulator technology

▲ [15p-B9-11] GeO₂ reduction and Si oxidation at SiGe/GeO₂ interface in UHV annealing

〇(D)Woojin Song¹, Akira Toriumi¹ (1.The Univ. Tokyo)

Keywords:Ge reduction, SiGe

In this study, the reduction reaction of SiGe/GeO₂ gate stack is discussed. It was found that, when the stack was annealed in UHV, the GeO₂ layer disappeared and a very thin SiO_x layer was formed. Comparing the XPS peak intensities of each species (Ge⁰⁺, Ge⁺⁴, Si⁰⁺, Si⁴⁺) suggests that the only small portion of oxygens in the GeO₂ layer was used to form SiO_x. It was observed that Ge⁰⁺ peak was newly observed in XPS measurement, verified by annealing of Si/GeO₂ stack and HF-last treatment. The experimental result suggests that GeO₂ layer on SiGe can be reduced and remained as metallic Ge atoms in the substrate.