| Summary: | 碩士 === 國立暨南國際大學 === 電機工程學系 === 103 === In order to quickly manufacture samples of recession to near ultraviolet light-emitting diode, we use three different methods for experiment. First, put LED in steam environment and execute reverse bias’s operation continually. We found that the result of the gold particles’ diffusion is similar to the former experiment of the red light-emitting diode’s diffusion, but the situation of gold particles’ diffusion is far more serious. Second, put LED in salt spray environment and execute forward bias’s operation continually. In this way, we use two different intensity of current to observe the recession. The result shows that chloride ion in salt spray environment has the phenomenon of diffusion. After that we executed a comparison of continually forward bias’s and reverse bias’s operation in steam environment and in salt spray environment, we found that the surface of the sample by forward bias’s operation has the phenomenon of heat accumulation, and the electrode pad of the sample by reverse bias’s operation has the phenomenon of heat accumulation. These phenomena could be called ‘’current crowding’’. The third method, which is based on the second experiment, subdivided forward bias’s current into three different groups by intensity to do electrical reliability tests and compare the differences.By various reliability analyses, such as Focused Ion Beam (FIB), Scanning Electron Microscope (SEM), Electron Spectroscopy of Chemical Analysis (ESCA), Energy dispersive X-ray spectroscopy (EDX), these electric and optical measurements and Thermal Image Process can observe the surface’s lighting and structural deterioration of aluminum gallium nitride (GaAlN) ultraviolet light-emitting diode in damp environment.
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