III-nitride LED material characterization and device fabrication

Summary form only given. Common material characterization techniques are evaluated for their ability to grade and distinguish between various sources of MOCVD grown III-nitride LED heterostructures on sapphire. in a mature semiconductor substrate technology (such as silicon), device performance would be expected to depend mostly on fabrication issues, since the characteristics of substrate material vary negligibly from vendor to vendor In an emerging material technology such as MOCVD III-nitride however, the quality of the epitaxial layers on the substrate is at least as important as the details of the fabrication process. We have used common semiconductor material characterization techniques: optical microscopy, atomic force microscopy, x-ray diffraction, time resolved photoluminescence, and transmission electron microscopy to investigate several different MOCVD-grown M-Nitride LED materials from commercial vendors and university groups. In most cases, the material characterization results depend in some way on the source of the material. We have also fabricated several different geometries and sizes of epir-up LED devices using the same set of MOCVD materials. With the aid of software simulation tools, we are currently working to correlate device performance with material characterization results.