Electronic trap characterization of the Sc<inf>2</inf>O<inf>3</inf>La <inf>2</inf>O<inf>3</inf> high- κ gate stack by scanning tunneling microscopy

Abstract

The tunneling current versus voltage characteristic of the Sc2 O3 La2 O3 Si Ox high- κ gate stack is examined using scanning tunneling microscopy in ultrahigh vacuum. Different measurement bias polarities allow information on the location (i.e., in the high- κ or interfacial Si Ox layer) of the electronic traps to be extracted. Two types of localized leakage sites may be distinguished. Lowering of the electron barrier height and trap-assisted tunneling are proposed as the two leakage mechanisms. © 2008 American Institute of Physics.