Tailoring of interfaces in amorphous silicon–germanium multilayers on the atomic scale by ultra-high gravity

Abstract

Amorphous Si/Ge multilayers containing diffuse interfaces have been prepared, heated in an ultra-centrifuge and subsequent interface structure modifications observed by X-ray reflectivity. The thickness of the Si/Ge and Ge/Si interface zones became asymmetrical owing to various effects occurring on the different atoms parallel to the direction of gravity-induced diffusion. The technique could prove useful for tuning physical (electronic, magnetic or optical) properties of layered structures.

Keywords:

• diffusion
• interfacial structures
• X-ray scattering
• amorphous semiconductors
• experimental
• multilayer

Acknowledgements

This work was supported in part by the Global COE programme of Pulsed Power Science. The synchrotron radiation experiments were performed at beamline BL15 of the SAGA-LS with the Nanotechnology Network Project (Kyushu-area Nanotechnology Network) of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. We acknowledge the support of the OTKA Board of Hungary (No NF101329 and C80126), the TAMOP 4.2.1./B-09/1/KONV-2010-0007 project (implemented through the New Hungary Development Plan co-financed by the European Social Fund, and the European Regional Development Fund). One of the authors (Z. Erdélyi) is a grantee of the ‘Bolyai Jáanos’ scholarship.