High conductivity beta-Ga2O3 formed by hot Si ion implantation

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 degrees C) and high temperature (HT, 600 degrees C) Si implants were carried out into MBE grown (010) beta-Ga2O3 films to form similar to 350 nm deep Si-doped layers with average concentrations up to similar to 1.2 x 10(20) 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 x 10(15) cm(-2) and an excellent mobility of 92.8 cm(2)/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.