Investigation of oxidation mechanism for ohmic formation in Ni/Au contacts to p-type GaN layers

Chi Sen Lee, Yow Jon Lin, Ching Ting Lee

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To investigate the function and mechanisms of oxidation, we present the ohmic performances for Ni/Au contacts to p-type GaN treated with various conditions. When the p-type GaN sample was preoxidized at 750 °C for 30 min in air ambient and then treated with (NH4)2Sx solution, we routinely obtained a specific contact resistance of 4.5 × 10-6 Ω cm2 for the Ni/Au contacts to samples alloyed at 500 °C for 10 min in air ambient. The fact that, in this configuration, ohmic performance improved one order of magnitude [compared with (NH4)2Sx surface treatment], is attributable to the strengthened formation of GaOx (aided by the preoxidation process), as well as the fact that more holes were induced on the oxidation-free p-type GaN surface.

Original languageEnglish
Pages (from-to)3815-3817
Number of pages3
JournalApplied Physics Letters
Issue number23
Publication statusPublished - 2001 Dec 3


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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