A direct high-k/Si gate stack has been proposed for gate oxide scaling. With LaCe-silicate, an EOT of 0.64 nm with an average dielectric constant (k av ) of 17.4 has been obtained and an extremely low gate leakage current (J g ) of 0.65 A/cm 2 . The flatband voltage (V fb ) can be controlled by the compositional ratio of La in the LaCe-silicate layer. Furthermore, incorporation of Ge atom into the silicate layer can effectively shift the V fb to positive direction.
IntroductionThe scaling in gate dielectric below equivalent oxide thickness (EOT) of 0.7 nm essentially requires a technique to directly contact high-k dielectrics to Si substrate with good interfacial property [1]. Several techniques, including cycle deposition and annealing, or oxygen scavenging process, have been so far reported to achieve a direct contact of high-k/Si structure [2,3]. The high-k/Si interface with HfO 2 is sensitive to the oxygen partial pressure during the process, so that one must choose a process within a window to achieve a direct high-k/Si structure (Fig.1). On the other hand, La 2 O 3 can achieve a direct high-k/Si interface by forming a silicate layer with fairly nice interface properties [4]. However, the excess formation of silicate results in the increase in EOT. CeO 2 has an advantage in the wide process window to achieve a direct high-k/Si interface. In terms of gate leakage current (J g ), silicates have advantage in widening the band gap at the cost of EOT (Fig.2). Therefore, this work focuses on the combination of a Si-rich Ce-silicate with La 2 O 3 to achieve a direct high-k/Si interface with both reduction in J g and EOT.
Spectroscopic and kinetic study of xenon after a multiphonic excitation of the 5d I 5 I JJ and 5d I z I5=3 states P Berejny, P Millet, M Saissac and Y Salamero Centre de Physique Atomique. URA No 277, Universit6 Paul Sabatier. 118 mute de Narbmne, 31062 Toulouse Cedex. France Abstract We present MRI luminescence and ionization studies of xenon aller a three-photon excitation of the 5 d l $ l i j or Sd1;1,=3 stafe by a tunable and pulsed laser beam. Emission and exciIation speck?, as well as ionization spectra have been obtained at a large range of pressures (fmmafew T~ioatmospherjcpressure). Thetemporal analysisofthehrst(l4Snm)and second (180 nm) continua of xenon showed the cmxistence of two luminescence components. The first one, essentially the 145 nm emission, was very slow and included ionization and dissociative molecular recombination steps. The second was fast and correlated to the radiative and collisional disappearance of the 5dl$l,s state, initially produced by three-photon absorption. It was possible to make a numerical processing of the 180 nm emission by a sum of exponential terms. Various time constants could be deduced and a kinetic schema of the mctional processes has been proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.