Zn ion implantation along the c axis for formation of highly resistive GaN layers

Zn ion implantation along the c axis was investigated in order to fabricate a highly resistive GaN layer. It was calculated that Zn ions effectively transfer their energy to the crystal atoms due to the heavy mass. This energy transfer was able to create implanted damage, which induced the highly resistive layer. Secondary ion mass spectroscopy (SIMS) profile of Zn atoms revealed that Zn ions penetrated over 1 μm into GaN layer at the ion energy of 350 keV. In the electrical characterization of the Zn implanted layer, it was found that thermal annealing at 500°C removed the Poole-Frenkel current and high sheet resistance of 2 × 10¹³ Ω/sq was obtained. AlGaN/GaN HEMT (high electron mobility transistor) with Zn implanted isolation had good electrical characteristics.