Dice Question Streamline Icon: https://streamlinehq.com

Demonstrate step-edge-guided nucleation and unidirectional epitaxial growth of InSe/In2Se3 on vicinal-stepped substrates

Demonstrate step-edge-guided nucleation and unidirectionally oriented epitaxial growth of InSe or In2Se3 thin films on vicinal-stepped substrates (e.g., off-cut sapphire), and ascertain the growth parameter space—such as temperature, precursor flux ratios, and flow modulation—needed to realize aligned, wafer-scale single-crystal films.

Information Square Streamline Icon: https://streamlinehq.com

Background

Wafer-scale, high-mobility indium selenide films require epitaxial strategies that minimize defects, control stoichiometry, and align domains. Unidirectional epitaxy via step-edge-guided nucleation has enabled wafer-scale single crystals in certain TMDs, suggesting a possible pathway for indium selenides.

Despite promising advances in MOCVD and MBE for indium selenides, achieving step-edge-guided nucleation and orientation control on vicinal substrates has not yet been realized, limiting prospects for large-area single-crystal films compatible with CMOS BEOL integration.

References

unidirectionally oriented epitaxial growth—similar to recent advances in the epitaxial growth of wafer-scale group-VI TMDs single crystals97—holds potential for producing high-quality thin films, given the fact that step-edge-guided nucleation and growth of InSe or In2Se3 on a vicinal-stepped substrate (e.g., sapphire with an off-cut angle) has yet to be observed.

— Indium selenides for next-generation low-power computing devices (2503.12708 - Song et al., 17 Mar 2025) in Scalable Thin-Film Deposition — Thin film growth