First-principles studies of the defect formation in III-V FETs grown by fin replacement method

First-principles investigations are used to study the formation of defects in III-V fins grown using the fin replacement method or aspect ratio trapping technique. We show that, during the growth of the III-V, the formation of intermediate chemical states with the precursors leads to the creation of in-diffused Mg/Zn and Al₂O₃ suboxide. We also show that the poor quality of the III-V crystals could enhance the in-diffusions of Mg/Zn and lead to the deposition of Aland Mg-oxides at the III-V/SiO₂ interface. Our prediction is consistent with experimental observations. These defect formations could be an origin of the degradation of the electrical reliability of III-V fin-shaped field-effect transistors. In order to find a way to prevent these defect-related issues, alternative p-type dopants with a high tolerance to these defect formations have been investigated theoretically. To decrease the difficulties met in the fabrication of III-V fin, it is important to understand the nature of the defects present using ab initio approaches.