The invention relates to a scanning tunnel
microscope, in particular to a morphology controllable scanning tunnel
microscope needle point preparation
system. The
system comprises a
corrosion platform,a working circuit, and
control software, and can be used for preparing various needle points for STM tests. The
corrosion platform comprises an electrolytic tank filled with corrosive liquid, a probepositioning mechanism used for fixing and adjusting the position of a
metal wire and a monitoring platform capable of observing the change of the shape of the needle point in the
corrosion process inreal time; the working circuit supplies power to the electrolytic tank, and meanwhile, acquires the
voltage signals of the needle point, and feeds back to the
computer control software, and a stepping motor is controlled by a motor
driving circuit to complete feeding and lifting motions of the probe; the
control software controls a programmable power supply to output currents in different changemodes and timely cuts off the power supply when the needle point is pulled off according to the
voltage signal fed back by an acquisition card, so that the stepping motor is triggered to extract the needle point. The controllable operation of the dynamic corrosion process is realized based on real-
time control, real-time observation and feedback, so that a needed needle point for the STM with different morphologies can be prepared.