Gallium Nitride (GaN) and Indium Gallium Nitride (InGaN) have
become important semiconductor materials for the LED lighting
industry. Recently, a photoluminescence (PL) technique for direct
in-situ characterization of GaN and InGaN layers during epitaxial
growth in a planetary metalorganic vapor phase epitaxy (MOVPE) reactor was
reported. The PL signals reveal – at the earliest possible stage – information about current layer thickness, temperature, composition, surface roughness, and self-absorption. Thus, the PL data is valuable for both controlling and optimizing the growth parameters, thereby promising both better devices and a better yield for the LED industry. This technical report describes an extension of this PL technique to close coupled showerhead (CCS) reactors with narrow optical viewports. In contrast to the wide aperture optics in previous investigations, a compact and all-fiber optical probe without voluminous lens optics, filter elements or beam splitters was used.
TM – Technical Measurement is a professional journal for application-based industrial measurement technology, a key component of systems for automation, process monitoring, quality control, and security. It's the official organ of the AMA (Association for Sensor Technology) and the NAMUR (Process-Industry Interest Group for Automation Technology). It also includes notifications from the GMA (VDI/VDE-Society for Measurement and Automatic Control).