AVS 52nd International Symposium
    Electronic Materials and Processing Monday Sessions
       Session EM-MoM

Paper EM-MoM7
Magnesium Oxide as a High-K Gate Dielectric

Monday, October 31, 2005, 10:20 am, Room 309

Session: Electronic Properties of High-k Dielectrics and their Interfaces
Presenter: L. Yan, University of North Carolina-Chapel Hill
Authors: L. Yan, University of North Carolina-Chapel Hill
C.M. Lopez, University of North Carolina-Chapel Hill
E.A. Irene, University of North Carolina-Chapel Hill
Correspondent: Click to Email
The presently considered candidate high @Kappa@ dielectric materials are reactive with Si and SiO@sub 2@ and most metals yielding undesirable interfacial electronic properties. While magnesium oxide (MgO) does not have as high of a @Kappa@ value (about 9.8 for bulk material) as many of the other candidate dielectrics (e.g., ZrO@sub 2@ and HfO@sub 2@), it has its unique advantages such as chemical inertness enabling sharp interfaces and wide bandgap (7.3 eV) for large band offsets with silicon (Si) to minimize leakage. In this study, MgO thin films were deposited via reactive rf sputtering on both bare Si and SiO@sub 2@ coated Si. In situ spectroscopic ellipsometry (SE) and Mass Spectrometry of Recoiled Ions (MSRI) were used to monitor the film growth in real time and cross-sectional transmission electron microscopy and atomic force microscopy were used to determine interface and surface roughness, respectively. Capacitance versus voltage (C-V) and conductance (G(@omega@)) versus gate voltage (G(@omega@)-V) measurements were performed on capacitor structures in order to determine @Kappa@, and the density of interface states (D@sub it@), respectively. Thus far a value of about 8 was obtained for the static dielectric constant for 10 nm films and interface charge and D@sub it@ results are comparable with SiO@sub 2@ on Si. Based on our measured properties it is concluded that thin MgO films can provide a high K dielectric for many electronic applications. @FootnoteText@ This work is supported by the National Science Foundation (NSF) Materials Research Division.