Interface characterization of high-quality SrTiO3 thin films on Si(100) substrates grown by molecular beam epitaxy

Single-crystal SrTiO3 has been grown on Si(100) using molecular beam epitax y (MBE). The growth conditions. especially at the initial stage of nucleati on, have a great impact on the SrTiO3/Si interface. A regrowth of an amorph ous interfacial layer as thick as 23 Angstrom has been observed and identif ied as a form of SiOx. This is a direct result of an internal oxidation dur ing the growth of the STO film due to the oxygen diffusion and reaction wit h the silicon substrate at the interface. The optimization of the depositio n process in terms of growth temperature and oxygen partial pressure has le d to an interfacial layer as thin as 11 Angstrom. Metal oxide semiconductor (MOS) capacitors with an equivalent oxide thickness t(ox) of 12 Angstrom a nd a leakage current of 2 X 10(-4) A/cm(2) have been obtained for a 50 Angs trom SrTiO3. (C) 2000 Elsevier Science B.V. All rights reserved.