Silicon
single-electron/hole transistors (SETs/SHTs) and super-high frequency
nanoelectromechanical resonators show great potential in quantum computation,
sensing and many other areas.
Recently,
a group led by Prof. Guo Guoping from the University of Science and Technology
of China of the Chinese Academy of Sciences, collaborating with Prof. Zhang
Zhen's group from Uppsala University, Sweden, designed and fabricated
CMOS-compatible suspended SHT devices which worked as super-high frequency nanoelectromechanical
resonators. The work was published in Advanced Materials.
The
researchers developed the devices using standard complementary
metal-oxide-semiconductor (CMOS) fabrication technology, which is convenient
for large-scale integration. The observed Coulomb diamond transport features
confirmed the formation of SHT.
When
suspended, the SHT can also work as a super-high frequency
nanoelectromechanical resonator, demonstrating excellent mechanical properties.
At ultra-low temperature and under high vacuum, the device showed single-hole
tunneling behavior and a mechanical resonance at a record high value of 3 GHz.
These
properties will be helpful for exploring the interactions between mechanical
vibrations and charge carriers, and investigating potential quantum effects.
Besides,
the researchers found that the electrical readout of the mechanical resonance
mainly relied on piezoresistive effect, and was strongly correlated to
single-hole tunneling. In the SHT regime, the piezoresistive gauge factor was
an order of magnitude larger than that at other different driving powers. This
property can be applied to study the piezoresistive effect of silicon in
nanoscale and more novel mechanical sensing devices' design.