Electron cyclotron resonance equipment with variable flare angle of horn antenna

Abstract

An electron cyclotron resonance equipment generates plasma by application of a processing gas and microwave energy into a vacuum chamber having a wafer therein in an environment of reduced pressure. The equipment includes a horn antenna assembly mounted onto an uppermost end of the vacuum chamber for radiating the microwave energy supplied from a high-frequency generator into the vacuum chamber. The horn antenna enables extension and retraction in a lengthwise direction to change a flare angle of the horn antenna. The equipment is provided with a fixed antenna and a plurality of mobile antennas to configure a horn antenna assembly, thereby enabling control of the flare angle in the horn antenna as a result of displacement of the mobile antennas. Thus, the uniformity in radiation of the microwave energy within plasma chamber can be controlled with efficiency.

Dependencies are inferred from the claim text.