Combining HRTEM–EELS nano-analysis with capacitance–voltage measurements to evaluate high-κ thin films deposited on Si and Ge as candidate for future gate dielectrics

• Published in: Microelectronic engineering 2011-04, Vol.88 (4), p.419-422
• Main Authors: Schamm-Chardon, S., Coulon, P.E., Lamagna, L., Wiemer, C., Baldovino, S., Fanciulli, M.
• Format: Article
• Language: English
• Subjects: Aberration corrected high resolution transmission electron microscopy (HRTEM); Annealing; Applied sciences; Atomic structure; Capacitance-voltage measurements; Cold working, work hardening; annealing, quenching, tempering, recovery, and recrystallization; textures; Condensed Matter; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Deposition; Dielectric constant; Dielectric properties of solids and liquids; Dielectrics; Dielectrics, piezoelectrics, and ferroelectrics and their properties; Electron and ion emission by liquids and solids; impact phenomena; Electron energy loss spectra; Electron energy loss spectroscopy (EELS); Engineering Sciences; Erdoped HfO2; Exact sciences and technology; Heat treatment; High-k dielectric stacks on Si and Ge; Impact phenomena (including electron spectra and sputtering); La-doped ZrO2; Materials Science; Mathematical models; Metals. Metallurgy; Micro and nanotechnologies; Microelectronics; Nanoanalytical electron microscopy; Nanostructure; Oxides; Permittivity; Permittivity (dielectric function); Physics; Production techniques; Rare earth metals; Semiconductors; Thin films; Treatment of materials and its effects on microstructure and properties
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2010.10.012

Aberration corrected transmission electron microscopy and electron spectroscopy are combined with electrical measurements for the quantitative description of the structural, chemical and dielectric parameters of rare earth/transition metal oxides thin films. Atomic structure near the interface and elemental profiles across the interface up to the surface of La-doped ZrO 2 and Er-doped HfO 2 films prepared by atomic layer deposition on Si(100) and Ge(100) are determined. Interfacial layers unavoidably form between the semiconductor substrate and the dielectric oxide after deposition and annealing. They are evidenced from a structural and chemical point of view. From the knowledge of the chemical extent of the interfacial layer and of the accumulation capacitance of the stack, it is possible to recover the dielectric constant of both the interfacial layer and the high-κ oxide layer constituting the stack using a multi-layers capacitor model approach. Oxides with permittivities higher than 30 are stabilized. Interfacial layers, silicate/germanate in composition, with permittivites, respectively, tripled/doubled compared to the one of SiO 2 are evidenced.