Investigation of the electrical properties of the alkaline-earth oxides BaO, SrO and Ba_0.7Sr_0.3O on Si(001) as alternative gate dielectrics

verfasst von

A. Cosceev, D. Müller-Sajak, Herbert Pfnür, Karl Rüdiger Hofmann

Abstract

We present first investigations of the electrical characteristics of high-k amorphous BaO, SrO and crystalline Ba_0.7Sr_0.3O films on n-Si(001). The MOS structures were grown in a UHV chamber on structured SiO₂ samples with Si(001) windows and were capped with Au layers afterwards for ex-situ electrical characterization. The smallest capacitance equivalent oxide thicknesses (relative to SiO₂) achieved so far in BaO, SrO and Ba_0.7Sr_0.3O MOS-diodes were 1.0, 3.5 and 1.6 nm at oxide thicknesses of 5, 10 and 10 nm, respectively. The corresponding leakage current densities at + 1 V accumulation bias were 2.1, 1.3 · 10^{- 5} and 4.7 · 10^{- 6} A/cm². The lowest interface trap densities observed at ∼ 0.2 eV below the conduction band in MOS-diodes with BaO, SrO and Ba_0.7Sr_0.3O films were 5.2 · 10¹², 9.7 · 10¹¹ and 9.1 · 10¹⁰ eV^{- 1} cm^{- 2}, respectively. These results suggest that alkaline-earth oxides might be interesting materials for application as high-k gate dielectrics.

Organisationseinheit(en)

Institut für Festkörperphysik
Institut für Materialien und Bauelemente der Elektronik

Typ

Artikel

Journal

Thin Solid Films

Band

518

Seiten

S281-S284

ISSN

0040-6090

Publikationsdatum

22.10.2009

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Oberflächen und Grenzflächen, Oberflächen, Beschichtungen und Folien, Metalle und Legierungen, Werkstoffchemie

Elektronische Version(en)

https://doi.org/10.1016/j.tsf.2009.10.108 (Zugang: Unbekannt)