Impact of Tunnel Etching Process on Electrical Performances of SON Devices

摘要

The removal of a sacrificial SiGe layer by isotropic etching has been newly improved for silicon-on-nothing (SON) technology by increasing etching selectivity to the Si conduction channel. Still based on CF_4 plasma chemistry, power and pressure are adapted in order to decrease etch rate and improve SiGe:Si selectivity. Both electrical characteristics and morphological observations are used to evaluate the characteristics of this technological step in terms of selectivity and uniformity. An original nonvolatile memory (NVM) concept based on this process will illustrate the interest in such etching development.