Engineering of ultra-thin sintered porous silicon virtual substrates for lattice-mismatched growth compliance and epilayer detachability

This is the authors' abstract. We don't add key points for this paper.

The air-sensitivity of mesoporous silicon layers etched on p-type wafers was evaluated comparing ambient-oxidized to methyl-capped samples, from which the unaltered pore/interpore sizes were obtained and linked to diffraction patterns and reflectivity data. Sintering of oxide-free nano/mesoporous bilayers produced ultra-thin porous epi-foils with full surface reconstruction at temperatures below 1000 °C. The epi-foils were in-plane tensely strained and exhibited good crystallinity and polished wafer-like surface roughness (RMSmin = 0.23 nm), emerging as potential compliant substrates for crack-free epitaxy of flat heterostructures. Furthermore, they were conveniently formed over a weakly bonded macroporous mesh that provided both structural stability and ease for detachment, establishing sintering below 1000 °C as a promising route to avoid collapsing and premature delamination of ultra-thin films.