Gallium Oxide Fabrication with Ion Beams

Gallium oxide is a novel ultra-wide band gap material, and the rationale for the current research project
is that its thin film fabrication technology is immature. In particular, the metastability conditions are
difficult to control during sequential deposition of different polymorphs with existing techniques. However, the
polymorphism may turn into a significant advantage if one can gain control over the polymorph multilayer
and nanostructure design. Our objective is to develop a method for the controllable solid state polymorph
conversion of gallium oxide assisted by ion irradiation. This fabrication method may pave the way for several
potential applications (e.g. in power electronics, optoelectronics, thermoelectricity batteries) and we will test
the corresponding functionalities during the project. Thus, we envisage multiple positive impacts and potential
benefits across a wide range of stakeholders.
I will introduce the aims and objectives of project paying specific attention to the planned methodology to
gain spatial control over the polymorph conversion. In the second half I will present the first results obtained
in the last 5 month. This includes broad beam irradiation which confirms the successful polymorph conversion
independent of primary ion species and the related exceptional radiation tolerance of the formed g-Ga2 O3 layer.
Further I will report the first spatially resolved focused ion beam (FIB) induced b- to g-Ga2 O3 polymorph
conversion. For this result different FIBs—available at the Ion Beam Center—have been used. These are in
particular the Helium Ion Microscope (HIM) using Neon ions, a conventional Gallium liquid metal ion source
(LMIS) based FIB as well as a liquid metal alloy ion source (LMAIS) FIB using Co ions. The confirmation of
the latter result also required the test and optimization of an electron backscatter diffraction (EBSD) based
analysis method.
I will end with an outlook on experiments foreseen for the rest of the project duration.
Support by the State of Saxony via Project 100629936 GoFIB—Gallium Oxide Fabrication with Ion Beams
and the COST Action 19140 FIT4NANO is acknowledged.