  Radiation tolerance is determined as the ability of crystalline materials to
withstand the accumulation of the radiation induced disorder. Nevertheless, for
sufficiently high fluences, in all by far known semiconductors it ends up with
either very high disorder levels or amorphization. Here we show that gamma/beta
double polymorph Ga2O3 structures exhibit remarkably high radiation tolerance.
Specifically, for room temperature experiments, they tolerate a disorder
equivalent to hundreds of displacements per atom, without severe degradations
of crystallinity; in comparison with, e.g., Si amorphizable already with the
lattice atoms displaced just once. We explain this behavior by an interesting
combination of the Ga- and O- sublattice properties in gamma-Ga2O3. In
particular, O-sublattice exhibits a strong recrystallization trend to recover
the face-centered-cubic stacking despite the stronger displacement of O atoms
compared to Ga during the active periods of cascades. Notably, we also
explained the origin of the beta-to-gamma Ga2O3 transformation, as a function
of the increased disorder in beta-Ga2O3 and studied the phenomena as a function
of the chemical nature of the implanted atoms. As a result, we conclude that
gamma/beta double polymorph Ga2O3 structures, in terms of their radiation
tolerance properties, benchmark a class of universal radiation tolerant
semiconductors.
