| 摘要 |
PROBLEM TO BE SOLVED: To observe a sample surface with high sensitivity without depending on an environmental temperature. SOLUTION: In a mechanical oscillation means 6 with a cantilever 4 for scanning a surface 3 of a sample 2, the cantilever 4 is vibrated at a resonance frequency f1 and the output is given to a frequency conversion circuit 13. A signal with an intermediate frequency f3 by a local oscillation frequency f2 being stabilized by a crystal oscillator 41 is given to a phase detector 45 of a phase synchronous loop circuit 14, and a voltage-controlled oscillation circuit 46 for generating a resonance frequency f4 being stabilized by a crystal oscillator 48 is provided. Depending on force due to interaction between the cantilever 4 and the surface 3, the resonance frequency f1 changes, the intermediate frequency f3 changes corresponding to the amount of changeΔf, and a voltage V1 of the phase detector 45 generates the fluctuation voltageΔV. The distance between the cantilever 4 and the sample 2 is maintained constantly so that the amount of changeΔf, namely the fluctuation voltageΔV, becomes constant.
|
