The development of vertical-type blue-light-emitting diodes using CLO (Chemical Lift-Off) process


The fabrication processes for vertical type-typ light-emitting diodes (LEDs) using metal buffer layers and chemical lift-off process were developed. These processes were applied to the fabrication of high-brightness blue LEDs. We succeeded in realizing high-brightness vertical-type blue LEDs. This is the first achievement in realizing vertical LEDs using the CLO process based on metal buffer. It is possible to make the n-contact area on the back side of vertical LEDs, so that the whole front side can emit light, which should give considerable advantage in fabricating high-brightness LEDs. This is not possible in the case of conventional LEDs, in which the n-contact are is fabricated on the front side. Besides, high power LEDs can be easily realized by wafer bonding technique of metal substrate with good thermal conductivity. This technique is suitable for mass production of vertical type high brightness and power blue LEDs. This result was introduced with Kahoku Shimpo (July 6).
Light emission from a fabricated vertical LED chip

Light emission from a fabricated vertical LED chip

Prof. Yao’s group (Physics of Electronic Materials)