| 摘要 |
PROBLEM TO BE SOLVED: To observe samples with high accuracy with respect to an approach control method and an apparatus of interatomic force microscope. SOLUTION: The approach control method includes modulating a reference voltage value 18 of Z feedback using an oscillator 33 capable of outputting a sine wave with a constant frequency; detecting a resonance frequency of a cantilever 7, shifted by a force acting between a probe 6 and a sample 1 when the probe 6 comes near the surface of the sample 1, by an FM demodulating circuit 16; controlling the shift amount to become equal to the feedback reference voltage value 18 by feedback control; modulating the Z-axis feedback reference voltage value 18 under a constant frequency; detecting the modulated signal as the force applied to the cantilever by the FM demodulating circuit; passing through a bandpass filter 30 to pass only the modulated frequency; and detecting the amplified amount by an effective value circuit 31 to stop a motor 19 if the amplitude value exceeds a limit value. COPYRIGHT: (C)2009,JPO&INPIT
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