Fabrication and packaging of a vertical-structured UV LED device by laser lift-off of Sapphire

Abstract

As UV LED technology advances, more and more new applications emerge. This paper describes design, fabrication and packaging of a vertical-structured UV LED device. Laser lift-off (LLO) method is used in the fabrication of a 45mil × 45mil LED, which allows us to remove the Sapphire substrate and absorptive GaN layers in the epitaxy. By doing this, the UV light absorption within the epitaxy is minimized and the efficacy of the device is significantly improved. In this paper, we will describe the fabrication process for achieving higher efficiency UVA chip, and report the device performance. Packaging technology and failure mechanisms under UV condition will also be discussed.