Strain analysis of SiGe layers on SOI: A tip-enhanced Raman spectroscopy approach for accurate germanium and strain percentage determination

International audience ; In recent years, strained silicon technologies have emerged as a key avenue in semiconductor research, offering a promising way to improve device performance. Among the key players in this field is the integration of silicon-germanium (SiGe) layers onto silicon substrates, which are strategically designed to induce strain and subsequently increase the overall efficiency of strained silicon devices [1].In this work, through a weighted comparison of Raman spectroscopy and high-resolution X-ray diffraction (HR-XRD) measurements with Tip-Enhanced Raman Spectroscopy (TERS) [2] measurements obtained on SiGe changes on SOI at different concentrations and thicknesses, a model was extracted that allows the simultaneous measurement of the percentage of Ge and strain present in nanometric volumes [3]. Furthermore, also the innovative titanium nitride (TiN) AFM probe [4], which allows clean room implementation for in-line characterisation, was used.The results highlight TERS as a powerful tool for monitoring the quality of semiconductor production lines, with unprecedented resolution and speed.