Formation of silicon on plasma synthesized SiO_xN_y and reaction mechanism

The application of silicon-on-insulator (SOI) substrates to high-power integrated circuits is hampered by self-heating effects due to the poor thermal conductivity of the buried SiO₂ layer. We propose to replace the buried SiO₂ layer in SOI with a plasma synthesized SiO _xN_y thin film to mitigate the self-heating effects. The SiO_xN_y films synthesized on silicon by plasma immersion ion implantation (PIII) exhibit outstanding surface topography, and excellent insulating characteristics are maintained up to an annealing temperature of 1100 °C. Hence, the polycrystallization in our SiO_xN_y materials is insignificant during conventional complementary metal oxide silicon (CMOS) processing. Using Si/SiO_xN_y direct bonding and the hydrogen-induced layer transfer, a silicon-on-SiO_xN_y structure has been successfully fabricated. Cross-sectional high-resolution transmission electron microscopy (HRTEM) and spreading resistance profiling (SRP) reveal that the bonded interface is abrupt and the top Si layer exhibits nearly perfect single crystalline quality. The reaction mechanism of SiO _xN_y and Si wafer bonding are also discussed. © 2004 Elsevier B.V. All rights reserved.