Gd-doping of HfO2

• Published in: Applied surface science Vol. 254; no. 14; pp. 4308 - 4312
• Main Authors: KETSMAN, Ihor, LOSOVYJ, Ya. B, SOKOLOV, A, JINKE TANG, ZHENJUN WANG, NATTA, M. L, BRAND, J. I, DOWBEN, P. A
• Format: Conference Proceeding Journal Article
• Language: English
• Published: Amsterdam Elsevier Science 15-05-2008
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Defects and impurities: doping, implantation, distribution, concentration, etc; Electron and ion emission by liquids and solids; impact phenomena; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Interfaces, heterostructures, nanostructures; Photoemission and photoelectron spectra; Physics; Surface and interface electron states; Surface states, band structure, electron density of states; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Valence bands; Density of states; Inorganic compounds; Physical radiation effects; 79.60.Jv; Transition element compounds; Doped materials; Hafnium oxide; Gd doping; 29.40.Wk; 81.05.J; Resonant photoemission; Fermi level; Gadolinium additions; Photoemission; Neutron beams; Oxide dielectric layers; 68.55.Ln; Photoexcitation
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2008.01.060

An increase in the density of states between the oxygen 2p bands and the Fermi level is seen with increasing Gd concentrations. In addition, for the Gd-doped HfO2 films, the Gd 4f photoexcitation peak at 5.5 eV below the valence band maximum was identified using resonant photoemission. Electrical measurements show pronounced rectification properties for lightly-doped Gd:HfO2 films on p-Si and for heavily-doped Gd:HfO2 films on n-Si, suggesting a crossover from n-type to p-type behavior with increasing doping level. In addition, there is an increase in the reverse bias current with neutron irradiation.