OPTICAL-PROPERTIES OF BONDED SILICON SILICIDE ON INSULATOR ((SOI)-O-2) - A NEW SUBSTRATE FOR ELECTRONIC AND OPTICAL-DEVICES

A new type of silicon on insulator substrate was fabricated using wafe r bonding. The inclusion of a highly conducting buried tungsten silici de layer below the silicon device layer but above the oxide film resul ts in many attractive properties for electronic and optical devices su ch as high performance bipolar transistors, power devices and optoisol ators. Commercial products are being developed using this new (SOI)-O- 2 material. However, to fully exploit this material a detailed underst anding of its optical and physical nature is required. To this end a s tudy of the buried silicide film? its interfaces and the overlying sil icon was carried out using spectroscopic ellipsometry and atomic force microscopy. It was found that the buried silicide undergoes a structu ral transformation, due to the thermal bonding anneal resulting in a r ough interface between it and the silicon overlayer. Crown Copyright ( C) 1998/DERA Published by Elsevier Science S.A.