Plasma generator

Abstract

A plasma generator generates a plasma by ionizing a gas with a high-frequency discharge in a plasma generating chamber so that electrons from the plasma are emitted outside the plasma generator through an electron emitting hole. The plasma generator includes an antenna that is provided in the plasma generating chamber and that emits a high-frequency wave, and an antenna cover that is made of an insulating material and that covers an entire body of the antenna. A plasma electrode having the electron emitting hole is made of a conductive material. A frame cover with a protrusion ensures conductivity by preventing an insulating material from accumulating on a surface of the plasma electrode on a plasma side in sputtering by the plasma.

Description

BACKGROUND OF THE INVENTION[0001]This application is a continuation-in-part of U.S. patent application Ser. No. 13 / 198,429, filed Aug. 4, 2011, claiming priority to Japanese Patent Application No. 2010-186824, filed Aug. 24, 2010, the contents of which is incorporated by reference in its entirety.[0002]1. Field of the Invention[0003]The present invention relates to a high-frequency discharge plasma generator that is used for suppressing an electrostatic charge (charge-up), etc., on a surface of a substrate when ion beam irradiation is carried out in an ion beam irradiation device that performs ion implantation, etc., by, for example, irradiating the substrate with an ion beam.[0004]2. Description of the Related Art[0005]A plasma generator is disclosed in Japanese Patent Application Laid-open No. 2002-324511 (Paragraphs 0031 to 0038 and FIG. 1) as an example of a high-frequency discharge plasma generator described above used for suppressing an electrostatic charge on a surface of a s...

AI Technical Summary

Benefits of technology

This patent relates to plasma generators used for ionization of gases using high-frequency discharge. The invention provides a method to prevent decrease in the PFG current by using an antenna and an insulating material. Additionally, a frame cover with protrusions is provided to prevent accumulation of insulating material and increase the PFG current. The invention also includes a conductive frame cover that serves as an electrode and increases the surface area, resulting in increased current flow. The use of carbon material for the frame cover and antenna ensures strong plasma resistance. Overall, this invention improves the performance and longevity of plasma generators.

Problems solved by technology

This results in stoppage of the ion beam irradiation device for maintenance for a long time.

Although the ions can obtain the electrons by recombining in the plasma, the electron current lost from the plasma cannot be compensated.

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