氧化对GaN基LED透明电极接触特性的影响

Reversible Effect of the Thermal Processing of Ni/Au Ohmic Contact to p-GaN

研究了热退火对InGaN/GaN多量子阱LED的Ni/Au p GaN欧姆接触的影响。发现在空气和N2气氛中交替地进行热退火的过程中Ni/Au接触特性显示出可逆现象。Ni/Au p GaN接触的串联电阻在空气中随合金化时间逐渐减小,在随后的N2中的热退火后会使该串联电阻增加,但在空气中再次热退火能使接触特性得到恢复。同时对Ni/Au p GaN接触在空气中合金化过程中的层反转的成因进行了讨论。

The effects of thermal treatment on Ni/Au ohmic contact to p-GaN were investigated by I-V measurements. It was found that there is reversible process of contact resistance when the Ni/Au contact to p-GaN is annealed in air and N_2 ambient alternately. The series resistance of Ni/Au contacts to p-GaN is reduced by the annealing in air. It is increased by a sequent annealing in N_2, and it can bereduced again by re-annealing in air. The mechanism for the layer-reversal of NiO/Au was also discussed.