Influence of Oxygen Composition and Carbon Impurity on Electronic Reliability of HfO2.

The effect of point defects such as oxygen vacancy and carbon interstitial on both electronic and structural characteristics of hafnium dioxide was analyzed by a quantum chemical molecular dynamics method. When a carbon atom as the impurity is introduced in hafnium dioxide, carbon impurity states (donor and acceptor) are formed in the band gap of hafnium dioxide. The band gap calculated from the energy difference between the donor and acceptor decreases to 1.6 eV. We conclude therefore, it is very important to control the composition of HfO2 films in order to assure the electronic performance and reliability of hafnium dioxide film. [ABSTRACT FROM AUTHOR]