AlGaN基深紫外LED的NiAu透明电极及其接触特性

Ohmic Contact Characteristics of AlGaN-based Deep-ultraviolet Light-emitting-diodes with NiAu Transparent Electrode

在p-AlGaN表面沉积Ni/Au/Ni/Au透明电极体系,通过传输线模型测试,研究了退火温度对Ni/Au/Ni/Au与p-Al Ga N材料接触特性的影响。结果表明,AlGaN基深紫外LED采用Ni/Au/Ni/Au金属体系,在600℃空气氛围下退火3 min形成p型半导体材料NiO。进一步优化Ni/Au/Ni/Au体系金属厚度,当Ni/Au/Ni/Au各层厚度由20/20/20/20 nm减薄至2/2/5/5 nm,并在600℃空气氛围退火3 min,其与p-AlGaN材料的接触电阻率从3.23×10^(-1)Ω·cm^(2)降到2.58×10^(-4)Ω·cm^(2)。采用上述优化的Ni/Au/Ni/Au体系制备的深紫外LED器件,器件光电特性得到了改善。在150 mA驱动下工作电压低至5.8 V;通过提升电极透过率,光输出功率提升18.9%。

A Ni/Au/Ni/Au transparent electrode system was deposited on the surface of p-AlGaN,and the effects of annealing temperature on the contact characteristics of Ni/Au/Ni/Au with p-AlGaN were studied by transmission line model.When the AlGaN-based deep ultraviolet LED adopted Ni/Au/Ni/Au metal system,meanwhile annealed at 600℃for 3 min,the results show that p-type semiconductor material NiO can be formed in the contact interface.The metal thickness of Ni/Au/Ni/Au system was further optimized.When the Ni/Au/Ni/Au layers were thinned from 20/20/20/20 nm to 2/2/5/5 nm,with the annealing condition at 600℃for 3 min,the specific contact resistivity de-creased from 3.23×10^(-1)Ω·cm^(2) to 2.58×10^(-4)Ω·cm^(2).Using the above optimized Ni/Au/Ni/Au system into LED chip process,the photoelectric characteristics of the LED device can be improved drastically.The operating voltage was reduced to 5.8 V at 150 mA,as the increase of the electrode transmittance,the optical output power was increased by 18.9%at the same current.