Study of Si Nanowire Surface Cleaning

Abstract

The Gate-All-Around (GAA) Field-Effect-Transistor (FET) is proposed as a promising candidate to replace Fin FET. In GAA architecture, Si Nanowires (NWs), which are fabricated by selective etching of SiGe from Si/SiGe multilayer fin structure, are used as channel. One of the concerns for fabricating GAA architecture is residual Ge, which is diffused SiGe from the Si/SiGe multilayer stack, in the Si NWs after their release. This Ge residue is a concern, since it could cause a degradation in device performance. The roughness of the Si NWs’ surface, which is a further factor in the degradation of device performance, was also examined. In this study, residual Ge removal and surface roughness with commodity chemistry was investigated. Finally, it was confirmed that residual Ge could be completely removed from Si without increasing Si surface roughness by dH2O2.