Low temperature growth of silicon dioxide using hydrogenation assisted nano-crystallization and plasma enhanced oxidation

We report the preparation and characterization of high quality silicon dioxide (SiO2) layers from nano-structured silicon thin films on silicon substrates at a maximum processing temperature of 350 °C. Hydrogenation-assisted plasma processing was used to prepare nano-porous silicon from amorphous silicon films and a subsequent plasma enhanced oxidation step converted the nano-crystalline silicon into silicon dioxide. The nano-structured materials were characterized by transmission electron microscopy, energy dispersive X-ray spectroscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. Metal–oxide-semiconductor (MOS) devices were prepared and the electrical properties of the oxide layer were investigated by current–voltage and capacitance–voltage measurements. The composition of the SiOx films was found to be near stoichiometry with a value of ‘x’ equal to 1.95 ± 0.18 and a dielectric constant of 3.8 ± 0.2. The leakage current in MOS capacitive devices was well below 1 nA.