마이크로 렌즈가 집적된 InGaN 계열 발광다이오드의 제작과 특성 분석

Abstract

We fabricated 460 nm InGaN-based light-emitting diodes(LEDs) integrated with microlens array of a UV-curable optical adhesive, and observed an enhancement of light output power of the LEDs. The epitaxial layer of InGaN-based LED were grown by organo-metallic vapor phase epitaxy (OMVPE). LED chips were fabricated using dry etching, metal deposition and thermal annealing process. Microlens array of UV-curable optical adhesive that had a relatively high value of the refractive index of 1.63 was then integrated on the LED chip by one step photolithography and thermal reflow process. Molding epoxy with the refractive index value of 1.53 was used for filling up plastic leaded chip carrier (PLCC) with LED chip after a die-bonding and a wire-bonding between the LED chip and metal pad on PLCC. The electrical and optical properties of the fabricated LEDs were investigated with the measurements of current versus light output intensities and voltage versus current using an integrating sphere coupled with a spectrometer.