Applications of Different Metals and Structures for Increase in Light Extraction on GaN-based Light Emitting Diodes

• Main Authors: Chiu-JungChen, 陳秋鎔
• Other Authors: Yan-Kuin Su
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/40634690945170068650

碩士 === 國立成功大學 === 微電子工程研究所碩博士班 === 98 === With the awakening of environmental protection, light emitting diodes play an important role in the solid lighting. To employ the light emitting diodes into general lighting use, the problems that should be solved are output light intensity and cost. In this thesis, there are some methods on the fabricating process for the vertical and lateral light emitting diodes respectively to increase the light output intensity. For vertical light emitting diodes, side walls are used around reflector to prevent reflector from being deteriorated by the acid and alkaline solutions. Then, this additional protection can maintain the reflectivity and resistance of metals for reflector. The light output intensity is 59.78% higher with the light emitting diodes with the side walls as protection of reflector. Moreover, to decrease the possibility of using strong acid solutions into the fabricating process, a different fabricating procedure is applied to minimize the damage induced to the reflector. For lateral light emitting diodes, the materials of metals for n and p pads, Cr/Pt/Au, are replaced with Cr/Pt/Ag. There are three advantages for replacing gold with silver: lower cost, higher reflectivity in the spectrum of blue light, and lower resistivity. With these advantages, the light output intensities for the large-sized and small-sized light emitting diodes with Cr/Pt/Ag as n and p pads are 16.63% and 12.32% higher respectively, and the forward voltages are 0.06 volts and 0.18 volts lower.