Out-of-Equilibrium Body Potential Measurement on Silicon-on-Insulator With Deposited Metal Contacts

Abstract

This article focuses on one of the floating body effects in silicon-on-insulator (SOI) substrates, the out-of-equilibrium body potential. Unlike the already existing studies which explore either SOI fully fabricated devices or SOI wafers measured with pressure probes, here the out-of-equilibrium body potential is explored in SOI substrates with deposited metal contacts. Chromium and gold/titanium contacts of various geometries were deposited on silicon films of SOI and the floating body potential was examined in each case. The effect of annealing on the device behavior was also investigated. The performance of the deposited metal contacts is evaluated through current and potential monitoring under quasi-static conditions. Depending on the workfunction difference between metal and silicon film, the current measurements show that the contact behavior is mainly ohmic-like or Schottky-like. While body potential manifests itself with Schottky-like contacts, it does not seem to exhibit a significant response with ohmic contacts. The influence of the contact architecture on the body potential signature is illustrated, enabling the selection of the proper contact layout for an enhanced body potential response.