Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9784115 | Materials Science and Engineering: B | 2005 | 4 Pages |
Abstract
In this work we have focused our attention on the role of the gas mixture (O2/Ar) used during HfO2 thin film processing by r.f. magnetron sputtering, to produce dielectrics with suitable characteristics to be used as gate dielectric. Increasing the O2/Ar ratio from 0 to 0.2, the films properties (optical gap, permittivity, resistivity and compactness) are improved. At these conditions, films with a band gap around 5Â eV were produced, indicating a good stoichiometry. Also the flat band voltage has a reduction of almost three times indicating also a reduction of the same order on the fixed charge density at the semiconductor-insulator interface. The dielectric constant is around 16 which is very good, since the surface of the silicon where the HfO2 films were deposited contains a SiO2 layer of about 3Â nm that gives an effective dielectric constant above 20, close to the HfO2 stoichiometric value (â¼25). Further increase on the O2/Ar ratio does not produce significant improvements.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
L. Pereira, P. Barquinha, E. Fortunato, R. Martins,