KJ Ceramics 31

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Detailed Program

Paper Number : LD-O05

Time Frame : 11:35~11:47

Presentation Date : Friday, 28, November

Session Name : LED and Display Materials

Session Chair 1# : Hyun-Suk Kim

Session Chair 2# : Hiroshi Fujioka

Electrical characteristics of low damage sputtered ITO Ohmic contact to p-GaN

Yu-Jung Cha

Sunchon National University

Keywords: Ohmic contact, ITO/GaN,

GaN based Light emitting diodes (LEDs) have many applications in daily life. For example, they are used LED traffic lights, full-color display, LCD panels, etc. The construct InGaN-based LEDs with high light-emitting efficiency, the p-type electrodes must have a high transmittance and a low contact resistance. Therefore, much research on p-GaN has involved Indium tin oxide (ITO) electrodes, having high permeability and low contact resistance.
Thin films of ITO thin film are typically deposited by e-Beam evaporation and sputtering. ITO deposition by sputtering achieves lower electrode resistance and higher optical transmittance than deposition by e-Beam evaporation. However, ITO films deposited by Sputtering on the p-GaN have a specific contact resistance higher than that of e-Beam evaporation. This higher resistance is known to be because of damage of the p-GaN layer by plasma generated during the sputtering process.
We report a method to minimize the plasma damage ITO sputtering onto p-GaN by simultaneously using DC power and RF power. By implementing this method, we observe ITO thin films with excellent contact resistance. These improved electrical properties are characterized by measuring IV curves across the RF-DC sputtered ITO on p-GaN Ohmic contact mechanism at temperatures ranging from 200 to 406 K.

Acknowledgements :

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