Development of high dielectric constant epitaxial oxides on silicon by molecular beam epitaxy

Thin films of perovskite-type oxide SrTiO3 have been grown epitaxially on S i(001) substrates using molecular beam epitaxy. Using reflection high energ y electron diffraction (RHEED) we have determined the optimum growth condit ions for these type of oxides directly on silicon. Also, observations of RH EED during growth and X-ray diffraction (XRD) analysis indicate that high q uality heteroepitaxy on Si takes place with SrTiO3(001)//Si(001) and SrTiO3 [010]//Si[110]. Thin SrTiO3 layers grown directly on Si were used as the ga te dielectric for the fabrication of MOSFET devices. An effective oxide thi ckness < 10 Angstrom has been obtained for a 110 Angstrom thick SrTiO3 diel ectric film with the interface state density around 6.4 x 10(10) cm(-2) eV( -1), and the inversion layer carrier mobilities of 220 and 62 cm(2) V-1 s(- 1) for NMOS and PMOS devices, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.