| 摘要 |
PURPOSE:To enable the digital handling of a titled device with high accuracy without contacting and the easy process control without damaging dielectric film by forming two sets of capacitor with the dielectric film in-between, coupling an oscillator separately thereto, mixing the output thereof and drawing out the signal corresponding to the thickness of the film. CONSTITUTION:Electrodes EM, ES and common Eg are disposed with a dielectric film X in-between, and are connected respectively to oscillators OSC1, OSC2, respectively. A differential signal of the two frequency outputs is drawn out from a mixer MIX and a level difference (y) is provided between the electrodes EM and DS to make the relation between the differential signal and the thickness of the film linear, whereby the thickness of the film is measured. |
