High conductivity β-Ga2O3 formed by hot Si ion implantation

Abstract

This work demonstrates the advantage of carrying out silicon ion (Si+) implantation at high temperatures for forming controlled heavily doped regions in gallium oxide. Room temperature (RT, 25 °C) and high temperature (HT, 600 °C) Si implants were carried out into MBE grown (010) β-Ga2O3 films to form ∼350 nm deep Si-doped layers with average concentrations up to ∼1.2 × 1020 cm−3. For such high concentrations, the RT sample was too resistive for measurement, but the HT samples had 82.1% Si dopant activation efficiency with a high sheet electron concentration of 3.3 × 1015 cm−2 and an excellent mobility of 92.8 cm2/V·s at room temperature. X-ray diffraction measurements indicate that HT implantation prevents the formation of other Ga2O3 phases and results in reduced structural defects and lattice damage. These results are highly encouraging for achieving ultra-low resistance heavily doped Ga2O3 layers using ion implantation.

Impact of electron irradiation on semi-insulating and conductive β-Ga2O3 single crystals

“…10 Various energetic particle irradiations, including electron, proton, neutron, N, Ge, and gamma-ray irradiation, have been employed to study the effects of irradiation on the structural, defect, and electrical properties of conductive b-Ga 2 O 3 . [11][12][13][14][15][16][17][18][19][20][21] As summarized in Table 1, particle irradiation created compensation centers and led to distinct decrease in free carrier density due to the capture of free electrons by the V Ga acceptor; H partially passivated the V Ga complex (V Ga -H) and acceptor-donor complex. For instance, the sheet resistance of Si-doped b-Ga 2 O 3 single crystal increased by more than nine orders of magnitude after N + irradiation.…”