【International Papers】Tuning electrical properties in Ga₂O₃ polymorphs induced with ion beams

      Recently, research teams such as MISIS, the Russian National University of Science and Technology, the University of Oslo in Norway, the Russian Academy of Sciences and the University of Florida in the United States published a paper on Gallium(III) oxide named Tuning electrical properties in Ga₂O₃ polymorphs induced with ion beams in the scientific journal Journal of Applied Physics.

ABSTRACT
      Ion beam fabrication of metastable polymorphs of Ga₂O₃, assisted by the controllable accumulation of the disorder in the lattice, is an inter-esting alternative to conventional deposition techniques. However, the adjustability of the electrical properties in such films is unexplored.In this work, we investigated two strategies for tuning the electron concentration in the ion beam created metastable κ-polymorph: adding silicon donors by ion implantation and adding hydrogen via plasma treatments. Importantly, all heat treatments were limited to ≤600 °C,set by the thermal stability of the ion beam fabricated polymorph. Under these conditions, silicon doping did not change the high resistive state caused by the iron acceptors in the initial wafer and residual defects accumulated upon the implants. Conversely, treating samples in a hydrogen plasma converted the ion beam fabricated κ-polymorph to n-type, with a net donor density in the low 10¹² cm⁻³ range and domi-nating deep traps near 0.6 eV below the conduction band. The mechanism explaining this n-type conductivity change may be due to hydro-gen forming shallow donor complexes with gallium vacancies and/or possibly passivating a fraction of the iron acceptors responsible for the high resistivity in the initial wafers.

Original paper