EPITAXIAL LAYER THICKNESS MEASUREMENTS BY REFLECTION SPECTROSCOPY

The trend toward full wafer processing of III-V compound device structures has created a need to obtain pertinent information about epitaxial layers in a non-destructive manner. Since semiconductors are transparent at wavelengths above their bandgaps the well-known principles of thin film interference can be applied to analyze these layers. Using reflectance spectroscopy, epitaxial layer thickness information has been obtained on a range of III-V compounds incorporated into a variety of heterostructures, including single epitaxial layers, multilayers and layers delineated by very thin markers.