Converting SOI to sSOI through Amorphization and Crystallization: Material Analysis and Device Demonstration

Abstract

Here, we demonstrate a new process to fabricate tensily strained Si On Insulator substrates (sSOI). The process is based on the epitaxial growth of Si 1-x Ge x on SOI substrate, the partial amorphization and crystallization of the Si/Si 1-x Ge x bilayers and the selective removal of the top Si 1-x Ge x film. Si tensile stress higher than 1.4 GPa is obtained. Complementary Metal Oxide Semiconductor Fully Depleted-SOI (CMOS FD-SOI) devices, with gate length lower than 15 nm, were fabricated on top of such substrate. For nFET devices, improvement in mobility is demonstrated with respect to devices built on standard SOI substrates.