Electrical Evaluation of Defects at the Si ( 100 ) / HfO2 Interface

Abstract

This work examines the electrical activity of defects at the interface with Si(100) for thin films (10-20 nm) deposited by injection metal oxide chemical vapor deposition. Based on an analysis of the capacitance-voltage response of structures, two clear peaks are detected in the interface state density profiles, at specific energies in the lower eV) and upper eV) bandgap. The densities of defects responsible for these peaks have been calculated as and respectively. These defects are present when the films were deposited at sufficiently low temperatures to prevent hydrogen passivation. The density of interface defects was not significantly different for films deposited on native oxide or hydrogen-terminated silicon surfaces. The position of these defects in the silicon bandgap corresponds to the location of dangling bond defects in the thermally oxidized system. films deposited at 450°C did not exhibit the prominent interface defects observed on films deposited at indicating hydrogen passivation during deposition. © 2004 The Electrochemical Society. All rights reserved.