Investigation of Electrical Properties of Thermally Annealed SiGe Metal-Oxide-Semiconductor Capacitors Prepared by Liquid-Phase Deposition of Silicon Dioxide

摘要

Room-temperature (30℃) silicon dioxide (SiO_2) has been grown on strained SiGe layers by liquid-phase deposition (LPD). Metal-oxide-semiconductor (MOS) capacitors have also been fabricated by annealing at various temperatures (200-400℃) in nitrogen. A very low leakage current density of 3.25 × 10~(-8) A/cm~2 was obtained at an electric field of 10 MV/cm for as-grown LPD-SiO_2 films. After annealing, the leakage current density decreased by one order of magnitude and the fixed oxide charge density also significantly decreased to 4.7 × 10~9 cm~(-2) in the capacitor annealed at 400℃. The mechanism by which this occurred is explained.