Radio-frequency filter for electrostatic chuck

The invention relates to a multifrequency radio-frequency filter for an electrostatic chuck. The electrostatic chuck is mounted in a plasma treatment device and used for fixing a to-be-treated substrate, wherein the plasma treatment device comprises a radio-frequency power supply provided with a plurality of radio frequencies and connected with a plasma generator; the electrostatic chuck comprises a heating electrode; and the radio-frequency filter is connected between the heating electrode of the electrostatic chuck and a heating power supply. The radio-frequency filter is characterized in that the radio-frequency filter comprises an iron-core inductor, an air inductor and a filter capacitor. A resonant frequency of the filter greater than a to-be-filtered frequency is selected as the resonant frequency of the filter. The radio-frequency filter with the structure can achieve more efficient filtering with a smaller size.