Epitaxial oxides on silicon grown by molecular beam epitaxy

Using molecular beam epitaxy, thin films of perovskite-type oxide SrxBa1-xT iO3 (0 less than or equal tox less than or equal to1) have been grown epita xially on Si(001) substrates. Growth parameters were determined using refle ction high energy electron diffraction (RHEED). Observation of RHEED during growth and X-ray diffraction analysis indicates that high quality heteroep itaxy on Si takes place with SrxB1-xTiO3(001)//Si(001) and SrxBa1-xTiO3[010 ]//Si[110]. Extensive atomic simulations have also been carried out to unde rstand the interface structure and give some insights into the initial grow th mechanism of the oxide layers on silicon. SrTiO3 layers grown directly o n Si were used as the Sate dielectric for the fabrication of MOSFET devices . An effective oxide thickness < 10 Angstrom has been obtained for a 110 An gstrom thick SrTiO3 dielectric film with interface state density around 6.4 x 10(10)/cm(2)/eV, and the inversion layer carrier mobilities of 220 and 6 2 cm(2)/V/s for NMOS and PMOS devices, respectively. (C) 2001 Elsevier Scie nce B.V. All rights reserved.