电子回旋共振等离子体源的特性

Characteristics of an electron cyclotron resonance plasma source

简要描述了一台频率为２．４５ＧＨｚ的电子回旋共振（ＥＣＲ）等离子体源的特性测试，结果表明，放电室内的等离子体密度和电子温度与静态磁场、微波输入功率和真空度等参数均有着密切关系。当磁场达到共振条件８７．５ｍＴ时，等离子体很易产生，但等离子体密度的最大值却出现在９３ｍＴ处。ＥＣＲ源在真空度为０．１—ｌＰａ间均能运行。由石英、Ａｌ２Ｏ３陶瓷和ＢＮ构成的微波输入富有良好的阻抗匹配，在微波功率为２００—７００Ｗ间，反射系数仅为１％，等离子体密度达５．８×１０１１ｃｍ－３，电子温度为３－１２ｅＶ，该源的寿命超过３００ｈ。

Characteristics of an electron cyclotron resonance (ECR) plasma source at a frequenccy of 2.45GHz were briefly described. The experiments showed that both plasma ion density and electron temperature in the charge chamber depended on the magnetic field, microwave power and gas pressure. It was found that the microwave breakdown occurred easily at the static magnetic field of 87.5mT. However, the highest plasma density was obtained at about 93mT. The microwave introducing window consisted of three dielectric plates of quartz, aluminum and BN, which allow better impedance matching with the plasma. The source can operate at gas pressure of 0.l-1Pa. The power reflection coefficient is about 1%. Plasma ion density of 5.8 × 1011cm-3 and electron temperature of 3-12eV have been obtained at the microwave power of 200-700W. The lifetime of the source is more than 300h.