Fermi level controlled point defect balance in ion irradiated indium oxide

Abstract

Fermi level controlled point defect balance is demonstrated in ion irradiated indium oxide (In 2 O 3 ). Specifically, our observations can be sub-divided into the formation of isolated Frenkel pairs and secondary defects, correlated with an increase and decrease in resistance, respectively. Importantly, by considering the net charge contribution from the most energetically stable Frenkel pair configurations, we explain the data trends for low doses and determine an upper limit for the Fermi level pinning. Moreover, by comparing the corresponding number of generated carriers with the ballistic defect generation rates, we estimate the dynamic annealing efficiency. Further irradiation toward higher doses is consistent with the buildup of secondary defects. As such, the present data may be of practical use in a variety of In 2 O 3 device applications requiring predictions of its radiation tolerance. In a broader perspective, the present methodology may be valuable for benchmarking defect simulation data in semiconductors in general.

15 MeV proton damage in NiO/β-Ga2O3vertical rectifiers

“…The fact that proton damage does not produce the hysteresis in I-V characteristics seen for gamma irradiation in these structures indicates that the reversible resistivity changes seen in other irradiated oxides is not occurring. For example, Borgersen et al [30,32] reported that irradiation of the related oxide, In 2 O 3 , with low doses of Si ions or and long UV exposures result in similar resistivity drops, interpreted as irradiation/illumination assisted desorption of oxygen containing species from the surface. This was consistent with the effect of post-irradiation exposure of the samples to an oxygen atmosphere partially restoring the resistivity.…”

“…While the Ga 2 O 3 is known to be relatively resistant to total dose damage [27,28], large reversible changes in current-voltage characteristics of the heterojunctions have been observed after Co-60 gamma ray exposure which appears to be due to conductivity changes in the NiO [29]. Other low dose ion irradiated oxides have also shown enhanced conductivity which in some cases has been linked to irradiation/illumination assisted desorption of oxygen containing species from the oxide surface [30][31][32][33]. There have also been recent demonstrations of single event burnout (SEB) in Ga 2 O 3 rectifiers [34], while simulations show the SEB threshold voltage of conventional Ga 2 O 3 MOSFETs is lower than that of state-of-the-art AlGaN/GaN HEMTs [35,36].…”

Oxygen Plasma Treatment to Enable Indium Oxide MESFET Devices

“…However, a change over several orders of magnitude is much more likely to be expected for n than for μ. [ 19 ]…”

“…Studies have been performed showing that intentionally damaged In 2 O 3 films display similar electrical properties with increasing damage regardless of their initial state (undoped, donor‐doped, or acceptor‐doped). [ 19 ] This is justified by the fact that the Fermi level in these samples is eventually raised into the conduction band by introduced intrinsic defects and defect complexes. Especially in the case of compensation doped samples (with Mg, as in this work as well) this leads to a drastic increase of the charge carrier density and, thus, decrease of the resistivity.…”

“…However, a change over several orders of magnitude is much more likely to be expected for n than for 𝜇. [19] The investigation on films of different thickness d was aimed at directly proving the existence of a SEAL in our samples. When charge transport is dominated by conduction through the bulk material, the charge carrier density n is independent of the layer thickness (n ∝ d 0 ).…”