对p-GaN/Ni/Au(5/10nm)界面处进行Pt^+注入,注入后的样品在空气中快速热退火处理5min,发现金属电极和p-GaN的欧姆接触特性得到明显的改善,接触电阻率从10^-1Ω·cm^2数量级降低到10^-3Ω·cm^2数量级。通过研究在不同Pt^+注入剂量(5×10^15、1×10^16、2×10^16cm^-2)和退火温度下接触电阻率的变化规律。在Pt^+注入剂量为1×10^16cm^-2,300℃空气氛围中退火得到了最低的接触电阻率,为3.55×10^-2Ω·cm^2。探讨了Pt^+离子注入引起欧姆接触改善的内在机制。
Pt^+ ions were implanted at the interface of p-GaN/Ni/Au (5/10nm), and then the sample was treated with rapid thermal annealing (RTA) in air for 5min. The ohmic contact characteristics between the metal electrode and p-GaN got obviously improved, and the specific contact resistance (Pc) reduced from 10^-1Ω·cm^2 order to 10^-3 Ω·cm^2 order. The effect of different implantation dose, i. e. 5 × 10^15 , 1× 10^16 , 2× 10^16 , and anneal temperature, i.e. 300,500,700℃, on Pc is investigated. The lowest Pc, i.e. 3. 555 × 10^-3Ω·cm^2 , is achieved after annealing in air at 300℃ in air for 5min with 1 × 10^16 cm^-2 Pt^+ ion implantation. The corresponding mechanisms of the improvement of ohmic contacts by Pt^+ ion implantation are discussed.