Ruqiang Bao, K. Watanabe, et al.
VLSI Technology 2020
In-line Raman spectroscopy for compositional and strain metrology throughout front-end-of-line manufacturing of next generation stacked gate-all-around nanosheet field-effect transistors is presented. Thin and alternating layers of fully strained pseudomorphic Si(1-x)Gex and Si were grown epitaxially on a Si substrate and subsequently patterned. Intentional strain variations were introduced by changing the Ge content (x = 0.25, 0,35, 0.50). Polarization-dependent in-line Raman spectroscopy was employed to characterize and quantify the strain evolution of Si and Si(1-x)Gex nanosheets throughout front-end-of-line processing by focusing on the analysis of Si-Si and Si-Ge optical phonon modes. To evaluate the accuracy of the Raman metrology results, strain reference data were acquired by non-destructive high-resolution x-ray diffraction and from destructive lattice deformation maps using precession electron diffraction. It was found that the germanium-alloy composition as well as Si and Si(1-x)Gex strain obtained by Raman spectroscopy are in excellent agreement with reference metrology and follow trends of previously published simulations.
Ruqiang Bao, K. Watanabe, et al.
VLSI Technology 2020
Daniel Schmidt, Curtis Durfee, et al.
JM3
Son Van Nguyen, Hosadurga Shobha, et al.
IITC 2021
Xunyuan Zhang, Huai Huang, et al.
IITC/AMC 2016