Wafer bonding using indium tin oxide intermediate layer for high brightness LEDs

Abstract

Direct-wafer-bonding technique has been used to fabricate high brightness light emitting diodes (LEDs). However, bonding processes were Usually performed at elevated temperatures, which may degrade the quality of the LED structure. In addition to this, the misorientation between two bonded wafers may cause defects between the wafers. In this Study, these two problems were solved by bonding the wafers with an indium tin oxide (ITO) polycrystalline film at temperature below 650 degreesC. It was found that the electrical resistance and optical loss decreased with the bonding temperature.