Wafer-bonded AlGaInP/Au/AuBe/SiO2/Si light-emitting diodes

Abstract

An AlGaInP light-emitting diode (LED) with a Au/AuBe/SiO2/Si mirror substrate has been successfully fabricated by the wafer bonding technique. The mirror-substrate LED is capable of emitting luminous intensity of 90 mcd under 20 mA injection. It is clearly far superior to the conventional absorbed-substrate LED with a distributed Bragg reflector structure (less than or equal to 1 mcd). This device exhibits normal p-n diode behavior with a forward voltage of less than 2 V operating at 20 mA. The leakage current is about 3 nA under a 36V reverse bias. This result indicates that the wafer bonding technique does not adversely affect the I-V characteristic of the LED device. Moreover, the emission wavelength of the bonded LED was independent of the injection current. The low forward series resistance and the Si substrate providing a good heat sink solve the joule heating problem inherent in conventional LEDs.