Development of SiGe Indentation Process Control for Gate-All-Around FET Technology Enablement

Methodologies for characterization of the lateral indentation silicon-germanium (SiGe) nanosheets using different non-destructive and in-line compatible metrology techniques are presented discussed. Gate-all-around nanosheet device structures with a total three sacrificial SiGe sheets were fabricated etch process conditions used to induce indent depth variations. Scatterometry spectral interferometry x-ray fluorescence in conjunction advanced interpretation machine learning algorithms quantify indentation. Solutions two approaches, average (represented by single parameter) as well sheet-specific indent, presented. Both scatterometry measurements suitable through parameter. Furthermore, enable fast solution path combining difference data spectra, therefore avoiding need full optical model solution. A similar approach can be employed monitoring; however, reference from cross-section transmission electron microscopy image analyses required training. It was found that spectra traditional combination achieve very good match data.