The theory of lift - mode scan capacitance microscope lm - scm is analyzed . under the hypothesis of small amplitude , it is found that the oscillation amplitude of the cantilever is directly proportional to the gradient of the surface capacitance 對升高模式掃描電容顯微鏡lm - scm進行了理論分析,發現在小振幅近似下針尖的振幅直接正比于樣品表面電容的梯度分布。