Pulsed liquid-injection MOCVD of high-K oxides for advanced semiconductor technologies

Polycrystalline SrTiO3 films were grown using either a mixture of precursors or a heterometallic precursor. The heterometallic precursor provides some advantages such as a lowering of the crystallisation temperature of the perovskite-type phase and a reduction of carbonate impurities at low temperatures. It also allows to keep the films composition constant over a wide temperature range (550-750 °C). The films are highly textured with [001]SrTiO3 parallel to [0 0 1]Si. The permittivity depends strongly on the films thickness (ɛr ∼ 30 for 10 nm and ɛr ∼ 100 for 100 nm). An equivalent oxide thickness of 1.36 nm (for physical thickness of 15.0 nm) was obtained for optimised SrTiO3 film, with a leakage current density of 10−2 A cm−2 at 1 V.