AVS 50th International Symposium
    High-k Gate Dielectrics and Devices Topical Conference Tuesday Sessions
       Session DI-TuM

Paper DI-TuM9
Si and Ge Surface Functionalization Characterized by In Situ and Ex Situ Infrared Spectroscopy

Tuesday, November 4, 2003, 11:00 am, Room 317

Session: High-k Dielectric Growth and Processing
Presenter: Y.J. Chabal, Rutgers University
Authors: M.M. Frank, IBM T.J. Watson Research Center and Rutgers University
M.-T. Ho, Rutgers University
S. Dörmann, Rutgers University
C.-L. Hsueh, Rutgers University
L.J. Webb, California Institute of Technology
N.S. Lewis, California Institute of Technology
S. Rivillon, Rutgers University
O. Pluchery, Université Paris 6, France
Y.J. Chabal, Rutgers University
Correspondent: Click to Email
Chemical functionalization and passivation of semiconductor surfaces is often necessary to foster uniform nucleation and high-quality interface formation in the deposition of ultrathin high-@kappa@ gate dielectrics and organic films. To understand the formation of such monolayers in wet, gaseous, or ultra-high vacuum environments, it is desirable to monitor surface reactions in situ. Utilizing infrared absorption spectroscopy, we have achieved such in situ monitoring with submonolayer sensitivity. We have performed both in situ and ex situ studies to gain mechanistic insight into surface chemical reactions on HF-etched, mostly H-terminated Si and Ge surfaces. Chemical species studied include: Cl, supplied via gas phase and wet chemistry, enabling subsequent activation of the Si substrate through hydroxylation; trimethylaluminum (Al(CH@sub 3@)@sub 3@) and other metal organic precursors, to initiate homogeneous atomic layer deposition or chemical vapor deposition of high-@kappa@ gate dielectrics (Al@sub 2@O@sub 3@ and HfO@sub 2@) onto hydrogen-terminated Si; and alkyl groups from wet chemistry, to passivate the Si. In particular, we shed light on the reactivity of Si-CH@sub 3@ and metal-CH@sub 3@ species formed in reactions with organic high-@kappa@ precursors and in wet chemical passivation. On Ge, we are investigating hydrogen passivation in HF using in situ methods, as well as the oxidation of such passivated surfaces. We compare and contrast the passivation and oxidation mechanisms on Si and Ge substrates.