Electrical properties of silicon-implanted β-Ga2O3:Fe crystals

Abstract

Ion implantation is a promising method for the development of β-Ga2O3-based technologies and devices. However, the physical principles of ion implantation for this particular semiconductor are still at the early stage of development. One of the primary tasks is the study of electrical properties of the ion-doped layers. In this work, we have investigated the electrical parameters of layers produced by ion implantation of a shallow donor impurity—silicon—into a semi-insulating β-Ga2O3 doped with iron and having a surface orientation of (−201). It is established that the activation efficiency of the implanted impurity significantly exceeds unity after post-implantation annealing at high temperatures. This indicates that not only silicon itself contributes to conductivity, but also defects formed with its (and, probably, iron) participation are involved. The temperature dependence of electron mobility is consistent with the theoretically calculated one under the assumption that, apart from shallow donors, there are also deep defect-associated donors and acceptors. It is assumed that the established properties are specific for the case of direct Si implantation into β-Ga2O3 doped with Fe.