dimensional metrology.
In this paper, a tactile probing system
based on capacitive sensor for precision metrology is presented. The capacitive sensor is fabricated by
MEMS technique, and a commercial micro-probe and the capacitive sensor are integrated together to
constitute the initial probing system. The signal processing circuit is designed to be based on AD7747
chip which is substantially a high resolution, - capacitance-to-digital converter (CDC). Then the experiment
set-up is configured and experimental results indicate that when a 0.3 mm probing head is used,
the probing system has a resolution of better than 10 nm along axial direction and better than 25 nm
along radial direction. With the low residual nonlinear error, the proposed system can therefore be used
for submicron measurement of small structures with dimension larger than 0.3 mm and depth down
to 2.3 mm.