Semiconductor Science and Technology · 2017 · 21 citations · 11 references
EngineeringElectrical EngineeringMaterials ScienceOptoelectronicsSemiconductor DevicesThin FilmsLight-emitting DiodesOptical Thin FilmsOptoelectronic DevicesPhotonic MaterialsSemiconductor Device MaterialsThin Film Optical PropertiesChippingCrack FormationDevice FabricationEpitaxial MaterialsFlip-chip Light-emitting DiodesLift-offLight-emitting DevicesOptical Characterization
We report on a chip design which allows the laser lift-off (LLO) of the sapphire substrate sustaining the epitaxial film of flip-chip mounted deep ultraviolet light emitting diodes. A nanosecond pulsed excimer laser with a wavelength of 248 nm was used for the LLO. A mechanically stable chip design was found to be the key to prevent crack formation in the epitaxial layers and material chipping during the LLO process. Stabilization was achieved by introducing a Ti/Au leveling layer that mechanically supports the fragile epitaxial film. The electrical and optical characterization of devices before and after the LLO process shows that the device performance did not degrade by the LLO.
11
Vanadium-based Ohmic contacts to n-AlGaN in the entire alloy composition
Ryan M. France, Tao Xu, Papo Chen et al. · Applied Physics Letters · 2007 · 111 citations · Full text
276 nm Substrate-Free Flip-Chip AlGaN Light-Emitting Diodes
Seongmo Hwang, D. V. Morgan, Amanda Kesler et al. · Applied Physics Express · 2011 · 53 citations