M.Sc. Research Topic

 

Deposition and Characterization of High Dielectric Constant La₂O ₃
Thin Films using Filtered Vacuum Arc Deposition

With the rapid progress of complementary metal-oxide semiconductor integrated circuit technology since the late 1980’s, Si-based devices, and in particular the field effect transistor (FET), have played a dominant role in electronics. Their continuing domination depends on continuing performance improvement, expressed empirically by Moore’s scaling law. Continuing improvement of integrated circuit performance is a requirement for realizing the International Technology Roadmap for Semiconductors (ITRS) – which requires reducing the feature size of the fundamental switching components, which allows integrating more transistors on a chip, enabling higher speed and reduced costs. The semiconductor industry’s demand for greater integrated circuit functionality and performance at lower cost prompted scaling of SiO₂ gate dielectric thickness down to 1.4 nm. However, fundamental limits in other device parameters, e.g. the dielectric gate capacitance, leakage currents, and channel carrier mobility, limit further scaling. Hence, new materials, e.g. with higher dielectric constant (k), will be required for gate insulators in future.

High-k metal oxides have been intensively investigated for providing substantially thicker gate insulators, to reduce leakage and to increase gate capacitance. The most commonly studied high-k materials for gate insulator applications are Al₂O₃, TiO₂, Ta₂O₅, HfO₂ and ZrO₂ for which 9<k<100. Recently, La₂O ₃ has been proposed as an alternative; however, its characteristics still needs further study. In the proposed project, a promising deposition technology -- filtered vacuum arc deposition (FVAD) -- will be used to investigate growth of high-k dielectric La₂O ₃ films on Si substrates.

 

Objectives:

The objectives of the proposed project is to develop high-k dielectric thin films having low leakage currents and high breakdown voltages, and to determine the relationship between deposition parameters and film properties.

 

The project will consist of:

(1)  Assembly of a vacuum arc deposition system.

(2) Developing a FVAD process for La₂O ₃ films suitable for gate insulators.

(3) Determining and understanding the relationship between the deposition parameters, and the film composition, microstructure, and electrical properties.

 

For additional details, please contact:

Prof. Reuven Boxman

Faculty of Engineering

tel:                    03-640-7364

e-mail: boxman@eng.tau.ac.il