  Gallium oxide and in particular its thermodynamically stable \b{eta}-Ga2O3
phase is within the most exciting materials in research and technology nowadays
due to its unique properties, such as an ultra-wide band gap and a very high
breakdown electric field, finding a number of applications in electronics and
optoelectronics. Ion implantation is a traditional technological method used in
these fields, and its well-known advantages can contribute greatly to the rapid
development of physics and technology of Ga2O3-based materials and devices.
Here, the current status of ion beam implantation in \b{eta}-Ga2O3 is reviewed.
The main attention is paid to the results of experimental study of damage under
ion irradiation and the properties of Ga2O3 layers doped by ion implantation.
The results of ab initio theoretical calculations of the impurities and defects
parameters are briefly presented, and the physical principles of a number of
analytical methods used to study implanted gallium oxide layers are
highlighted. The use of ion implantation in the development of such Ga2O3-based
devices as metal oxide field effect transistors, Schottky barrier diodes, and
solar-blind UV detectors, is described together with systematical analysis of
the achieved values of their characteristics. Finally, the most important
challenges to be overcome in this field of science and technology are
discussed.
