Company Name: Xiamen Powerway Advanced Material Co., Ltd
Tel: +86-592-5601404
Fax: +86-592-5745822
E-Mail: gan@powerwaywafer.com

Address: #3007-3008, No.89, Anling,Huli Developing Zone, Xiamen,China
Home > News > Effects of pre-annealed ITO film on the electrical characteristics of high-reflectance Ni/Ag/Ni/Au contacts to p-type GaN
Effects of pre-annealed ITO film on the electrical characteristics of high-reflectance Ni/Ag/Ni/Au contacts to p-type GaN

 

 

Ni/Ag/Ni/Au p-type contacts with first Ni layer of 0.5 nm were investigated.

A pre-annealed ITO film scheme was proposed to decrease the contact resistance.

Flip-chip LEDs fabricated with the proposed scheme showed better performance.

 


Abstract

In this study, a Ni/Ag/Ni/Au multilayer with first Ni layer of 0.5 nm was first optimized for high reflectivity (92.3%), low specific contact resistance (2.1 × 10−3 Ω cm2) and good attachment strength to p-type GaN. To further decrease the contact resistance, the p-type GaN surface was previously treated with pre-annealed indium-tin-oxide (ITO) film before deposition of the Ni/Ag/Ni/Au multilayer, and resulted in a lower specific contact resistance of 1.9 × 10−4 Ω cm2. The X-ray photoelectron spectroscopy results indicated that Ga 2p core level of the p-type GaN surface with the pre-annealed ITO film had a lower binding energy, leading to a reduction in the contact resistance. Furthermore, GaN-based flip-chip light-emitting diodes (LEDs) with and without the pre-annealed ITO film were fabricated. The average forward voltage of the flip-chip LEDs fabricated with the pre-annealed ITO film is 3.22 V at an injection current density of 35 A/cm2, which is much lower than that (3.49 V) of flip-chip LEDs without the pre-annealed ITO film. These results reveal that the proposed approach is effectively to fabricate high quality p-type contacts toward high power GaN-based LEDs.

Keywords

  • GaN
  • Ohmic contact
  • Pre-annealed ITO film
  • Flip-chip LED
  • SOURECE:SCIENCEDIRECT


If you need more information about GaN layers grown by MOVPE on GaN, please visit:
www.galliumnitrides.com or send us email at gan@powerwaywafer.com