Interfacial characteristics of fully depleted SiGe-on-insulator (SGOI) substrate fabricated by modified Ge condensation

A fully depleted SiGe-on-insulator (SGOI) substrate has been fabricated by a modified Ge condensation technique. The characteristics of the SiGe/buried-oxide (BOX) interface and the influence on the electrical performance of the SGOI substrate are investigated. The long oxidation time during the fabrication of the fully depleted (FD) SGOI substrate leads to Ge atom pileup at the SiGe/BOX interface, and consequently a large number of interfacial trapped charges are produced. Furthermore, our results disclose that Ge diffusion into the BOX increases the interfacial trapped charges and the fixed oxide charges during oxidation. As a result, the electrical properties of the FD-SGOI substrate degrade due to the poor SiGe/BOX interface.