Mapping of the mechanical response in Si/SiGe nanosheet device geometries
Conal E. Murray, Hanfei Yan, C. Lavoie, Jean Jordan‐Sweet, Ajith Pattammattel, Kathleen B. Reuter, Mohammad Hasanuzzaman, Nicholas A. Lanzillo, Robert R. Robison, Nicolas Loubet
Abstract
Abstract The performance of next-generation, nanoelectronic devices relies on a precise understanding of strain within the constituent materials. However, the increased flexibility inherent to these three-dimensional device geometries necessitates direct measurement of their deformation. Here we report synchrotron x-ray diffraction-based non-destructive nanoscale mapping of Si/SiGe nanosheets for gate-all-around structures. We identified two competing mechanisms at different length scales contributing to the deformation. One is consistent with the in-plane elastic relaxation due to the Ge lattice mismatch with the surrounding Si. The second is associated with the out-of-plane layering of the Si and SiGe regions at a length scale of film thickness. Complementary mechanical modeling corroborated the qualitative aspects of the deformation profiles observed across a variety of nanosheet sample widths. However, greater deformation is observed in the SiGe layers of the nanosheets than the predicted distributions. These insights could play a role in predicting carrier mobilities of future devices.