  We report the mechanically induced formation of a silicon-hydrogen covalent
bond and its application in engineering nanoelectronic devices. We show that
using the tip of a non-contact atomic force microscope (NC-AFM), a single
hydrogen atom could be vertically manipulated. When applying a localized
electronic excitation, a single hydrogen atom is desorbed from the hydrogen
passivated surface and can be transferred to the tip apex as evidenced from a
unique signature in frequency shift curves. In the absence of tunnel electrons
and electric field in the scanning probe microscope junction at 0 V, the
hydrogen atom at the tip apex is brought very close to a silicon dangling bond,
inducing the mechanical formation of a silicon-hydrogen covalent bond and the
passivation of the dangling bond. The functionalized tip was used to
characterize silicon dangling bonds on the hydrogen-silicon surface, was shown
to enhance the scanning tunneling microscope (STM) contrast, and allowed NC-AFM
imaging with atomic and chemical bond contrasts. Through examples, we show the
importance of this atomic scale mechanical manipulation technique in the
engineering of the emerging technology of on-surface dangling bond based
nanoelectronic devices.
