Mechanism of Ohmic Cr/Ni/Au contact formation on p-GaN

作者：Magdenko Liubov^*; Patriarche Gilles; Troadec David; Mauguin Olivia; Morvan Erwan; di Forte Poisson Marie Antoinette; Pantzas Konstantinos; Ougazzaden Abdallah; Martinez Anthony; Ramdane Abderrahim

来源：Journal of Vacuum Science and Technology B, 2012, 30(2): 022205.

DOI：10.1116/1.3688486

Detailed investigation of Ohmic Cr/Ni/Au based contact formation to p-GaN was realized by scanning transmission electron microscopy and energy-dispersive x-ray spectroscopy and compared to the Cr/Au bilayer metallization scheme. The authors found that it is essential to introduce a nickel film in Cr-based contacts and anneal the trilayer structure in air in order to suppress the Shottky barrier and thus obtain the Ohmic contact. Our findings also indicate that oxygen behaves as a dopant dispersed in chromium nitride matrix. Thus Ohmic trilayer Cr/Ni/Au contact to p-GaN annealed in air is formed by Ni-Ga-Au alloy mixed with Au-Ga-doped Cr2N crystalline composites. Possible ways for improvement of such types of contact are discussed.

• 出版日期2012-3