Optical approaches for controlling epitaxial growth

Optical spectroscopy of surface and near-surface regions has advanced to the stage where detailed measurements can be made and analyzed in real time. Here, we discuss reported and potential applications of optical probes for sample-driven closed-loop feedback control of semiconductor epitaxy. Parameters that have been controlled include temperature, thickness in both deposition and etching, and composition, including continuously graded compositions. Although considerable progress has been made, much remains to be done before these techniques become viable production tools. q1998 Elsevier Science B.V. All rights reserved.