The local control of mechanical strain and composition in ultra‐thin materials is a challenge for the semiconductor industry. In the production line, these controls require nondestructive, low‐latency, and high accuracy techniques. This article proposes the use of Raman spectroscopy to monitor the structure of ultra‐thin semiconducting materials, with an accuracy of in terms of strain. The Raman signal being however inherently weak, the extraction of strain and composition in the layer of interest may be in certain cases delicate. To predict the enhancement of Raman intensities in a given multilayered stack, we revisited already known interference effects, the so‐called interference‐enhanced Raman spectroscopy mechanism. We developed an open‐access simulation tool, working for stacks featuring as many layers as required: https: //github. com/CEA‐MetroCarac/ramanₐmpli. We validated this modeling tool by growing epitaxial silicon‐germanium (SiGe), a material present in a wide range of microelectronic devices. The SiGe layers were beveled at wafer scale using complementary metal‐oxide‐semiconductor processes. We successfully highlighted the enhancement of thin SiGe on Insulator, especially below. This stack‐dependent SiGe amplification offers promising perspectives for the anticipation of the best laser source (metrology) and the most relevant structures (process) while remaining dependent on product specifications.
Monteil et al. (Thu,) studied this question.