A helical wave antenna system

Abstract

The invention relates to a helical wave antenna system, comprising an insulating tube, a right-handed antenna wound on the insulating tube, an insulating layer sleeved outside the right-handed antenna, and a shielding sleeve sleeved outside the insulating layer, the shielding sleeve One end of the insulating tube is closed and connected with an air inlet pipe, one end of the insulating pipe abuts against one end of the shielding sleeve, the air inlet pipe communicates with the insulating pipe, and the outer peripheral surface of the shielding sleeve is provided with a shielding pipe. The invention has higher power coupling efficiency, enhanced ionization rate, increased plasma density, adopts a water-cooled antenna with a ceramic insulating layer, avoids parasitic discharge and micro-arc discharge, and has better efficiency and stability. The stable operation of the helicon wave for a long time provides a guarantee, provides technical support for the industrial application of the helicon wave plasma, and can be easily applied to different vacuum systems. Compared with the existing antenna, the applicability has also been greatly improved.

Description

technical field [0001] The invention relates to a helical wave antenna system. Background technique [0002] With the rapid development of cutting-edge technologies such as semiconductor manufacturing, material surface modification, and plasma space advancement, traditional low-temperature plasma sources such as capacitively coupled plasma (CCP) sources and inductively coupled plasma (ICP) sources can no longer meet Increasingly stringent technical requirements. The helicon wave has become one of the research hotspots of advanced low-temperature plasma sources due to its outstanding advantages such as high density, high efficiency, independent control of ion and electron energy, remote processing, and adjustable self-bias voltage. A helicon wave is a right circularly polarized (RCP) whistle wave that propagates only in a bounded magnetized medium, and its frequency is between the electron cyclotron frequency and the ion cyclotron frequency. The generation process of the he...

AI Technical Summary

Problems solved by technology

This parasitic plasma will contact and sputter the antenna material, causing the antenna material to be deposited and coated on the system components with adverse consequences, for example, if the insulating tube is sputtered to deposit the antenna material, the entire discharge condition will change

In addition, parasitic discharges are also very harmful to the precise diagnosis of plasmas, because we don't know whether the particles come from helicon discharges or parasitic discharges

In addition to parasitic discharge, some studies have shown that when the RF power is added to the submerged antenna, it may cause ignition on the inner wall of the vacuum chamber. We call it micro-arc discharge, which will disturb the plasma and affect the helicon wave. Steady-state operation of the discharge

Finally, the current in the antenna is large when operating at high power, and the ohmic heat is very serious. Since the antenna is immersed in a vacuum, it is difficult to dissipate heat. If the antenna temperature continues to rise, it will seriously affect the discharge stability, and even burn out the electrodes.

If these problems are not solved, it will seriously affect our steady-state long-term helical wave discharge in the range of large gas flow and large radio frequency power.

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