  For decades, mechanical resonators with high sensitivity have been realized
using thin-film materials under high tensile loads. Although there have been
remarkable strides in achieving low-dissipation mechanical sensors by utilizing
high tensile stress, the performance of even the best strategy is limited by
the tensile fracture strength of the resonator materials. In this study, a
wafer-scale amorphous thin film is uncovered, which has the highest ultimate
tensile strength ever measured for a nanostructured amorphous material. This
silicon carbide (SiC) material exhibits an ultimate tensile strength of over 10
GPa, reaching the regime reserved for strong crystalline materials and
approaching levels experimentally shown in graphene nanoribbons. Amorphous SiC
strings with high aspect ratios are fabricated, with mechanical modes exceeding
quality factors 10^8 at room temperature, the highest value achieved among SiC
resonators. These performances are demonstrated faithfully after characterizing
the mechanical properties of the thin film using the resonance behaviors of
free-standing resonators. This robust thin-film material has significant
potential for applications in nanomechanical sensors, solar cells, biological
applications, space exploration and other areas requiring strength and
stability in dynamic environments. The findings of this study open up new
possibilities for the use of amorphous thin-film materials in high-performance
applications.
