화학공학소재연구정보센터
Electrochemical and Solid State Letters, Vol.8, No.1, G17-G19, 2005
Low-resistance and reflective Ni/Rh and Ni/Au/Rh contacts to p-GaN for flip-chip LEDs
We report on the formation of high-quality ohmic contacts to p-type GaN (4 x 10(17) cm(-3)) using Ni (5 nm)/Rh (120 nm) and Ni (5 nm)/Au (5 nm)/Rh (120 nm) schemes for use in flip-chip light-emitting diodes (LEDs). Both the Ni/Rh and Ni/Au/Rh contacts become ohmic with specific contact resistances of 10(-5) to 10(-6) V cm(2), when annealed at 350 degrees C for 2 min in air ambient. LEDs are fabricated using the Ni/Au/Rh and Ni/Au contact layers, which give a forward-bias voltage of 3.32 and 3.45 V at injection current of 20 mA, respectively. This indicates that the Rh-based contacts could be suitable for high power flip-chip LEDs. (C) 2004 The Electrochemical Society.