1. Field of the Invention
The present invention relates to an antenna cover that protects an antenna of a plasma generating device.
2. Description of the Related Art
In a plasma generating device, for example, plasma electrons are accelerated by an RF electric field generated in the vicinity of an antenna in a plasma chamber and plasma is generated. At this time, if the antenna is exposed to the plasma, the antenna is sputtered, which results in becoming the pollution cause of the plasma. For this reason, a member for protecting the antenna from the generated plasma is provided. For example, a partition plate is provided between the plasma chamber and an antenna chamber to protect the antenna.
Because the protection member of the antenna is exposed to the plasma, the protection member is damaged by the plasma. If the protection member is abraded under an influence of the plasma and a hole is formed in the protection member, the antenna is exposed to the plasma and the plasma is polluted. If the protection member is formed thick or the antenna or the protection member is arranged to be distant from a generation position of the plasma, abrasion of the protection member can be decreased. However, generation efficiency of the plasma is deteriorated.