p-GaN表面Ni/Au电极欧姆接触特性的Pt^+注入改性研究

Study of the improvement of Ni/Au ohmic contact to p-GaN by Pt^+ implantation

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.cm2数量级降低到10-3Ω.cm2数量级。通过研究在不同Pt+注入剂量(5×1015、1×1016、2×1016cm-2)和退火温度下接触电阻率的变化规律。在Pt+注入剂量为1×1016cm-2,300℃空气氛围中退火得到了最低的接触电阻率,为3.55×10-3Ω.cm2。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.