Specific contact resistance ρc to p-GaN was measured for various structures of Ni/Pd-based metals and thin(20-30 nm thick)p-InGaN/p+-GaN contacting layers.The effects of surface chemical treatment and annealing temperature were ex-amined.The optimal annealing temperature was determined to be 550℃,above which the sheet resistance of the samples de-graded considerably,suggesting that undesirable alloying had occurred.Pd-containing metal showed～35％lower ρc com-pared to that of single Ni.Very thin(2-3.5 nm thick)p-InGaN contacting layers grown on 20-25 nm thick p+-GaN layers exhib-ited one to two orders of magnitude smaller values of ρc compared to that of p+-GaN without p-InGaN.The current density de-pendence of ρc,which is indicative of nonlinearity in current-voltage relation,was also examined.The lowest ρc achieved through this study was 4.9×10-5 Ω·cm2@J=3.4 kA/cm2.

Minglong Zhang;Masao Ikeda;Siyi Huang;Jianping Liu;Jianjun Zhu;Shuming Zhang;Hui Yang

School of Nano-Tech and Nano-Bionics,University of Science and Technology of China,Hefei 230026,China;Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences,Suzhou 215123,China

半导体学报（英文版）

[1]Minglong Zhang;Masao Ikeda;Siyi Huang;Jianping Liu;Jianjun Zhu;Shuming Zhang;Hui Yang-.Ni/Pd-based ohmic contacts to p-GaN through p-InGaN/p+-GaN contacting layers)[J].半导体学报（英文版）,2022(09):81-86

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