Dresden 2006 – scientific programme

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HL: Halbleiterphysik

HL 9: Poster I

HL 9.50: Poster

Monday, March 27, 2006, 15:15–17:45, P3

Improving the interface between silicon and La₂O₃ high-k dielectric — •Sandra Seidel, Christian Wolff, Andreas Aßmuth, Tanja Stimpel-Lindner, Hermann Baumgärtner, and Ignaz Eisele — Institut für Physik, Fakultät für Elektrotechnik, Universität der Bundeswehr München, 85577 München-Neubiberg, Deutschland

The traditional scaling of CMOS devices is reaching the fundamental limits of the standard materials. Therefore, new materials have to be introduced. The most critical point for the shrinking is the introduction of a high dielectric constant (high-k) material as alternative gate material. In general materials having dielectric constant around 10 are suggested for short term and materials having k > 20 for long term solution. Furthermore, the dielectric constant is not the only parameter to be taken into consideration. Other important parameters are band gap, band alignment and interface-state density. In this work, molecular-beam deposited La₂O₃ was studied as a possible high-k candidate. In direct contact with silicon, this binary oxide is unstable and interfacial SiO₂ and silicate layers are formed. Therefore, an engineered interfacial layer was required in order to take advantage of the potential high-k characteristics. This interface can be achieved by growing an ultrathin nitride layer between substrate and high-k material. Electrical characteristics and XPS results will be shown.