ELECTRIC FIELD SENSOR, SURFACE WAVE PLASMA SOURCE, AND SURFACE WAVE PLASMA PROCESSING DEVICE

To provide an electric field sensor capable of stably detecting a microwave electric field by suppressing the influence of noise and the like in a surface wave plasma source, and the surface wave plasma source and a surface wave plasma processing device using the same.SOLUTION: An electric field sensor includes: a probe 141 which serves as an inner conductor of a coaxial transmission line and is configured such that the tip is always in contact with the back surface of a microwave transmission window 110b; a tubular probe guide 142 which is provided on the outside of the probe 141, serves as an outer conductor of the coaxial transmission line, and has a tip that contacts the back surface of a flat slot antenna 81; an insulating member 143 provided between the probe 141 and the probe guide 142; a preload spring 144 that urges the probe guide 142 such that the tip is always in contact with the flat slot antenna 81; and a connector 145 that performs connection of a coaxial structure signal cable that takes out signals.SELECTED DRAWING: Figure 8 【課題】表面波プラズマ源において、ノイズ等の影響を抑制して安定してマイクロ波の電界を検出することができる電界センサ、ならびにそれを用いた表面波プラズマ源および表面波プラズマ処理装置を提供する。【解決手段】同軸伝送路の内部導体となり、先端がマイクロ波透過窓１１０ｂの裏面に常に接触するように構成されたプローブ１４１と、プローブ１４１の外側に設けられ、同軸伝送路の外側導体となり、先端が平面スロットアンテナ８１の裏面に接触するように構成された筒状をなすプローブガイド１４２と、プローブ１４１とプローブガイド１４２との間に設けられた絶縁部材１４３と、プローブガイド１４２を、その先端が平面スロットアンテナ８１に常に接触するように付勢する予圧スプリング１４４と、信号を取り出す同軸構造の信号ケーブルを接続するコネクタ１４５とを有する。【選択図】図８