To move an article in and out of plasma during plasma processing, the
article is rotated by a first drive around a first axis, and the first
drive is itself rotated by a second drive. As a result, the article
enters the plasma at different angles for different positions of the
first axis. The plasma cross-section at the level at which the plasma
contacts the article is asymmetric so that those points on the article
that move at a greater linear velocity (due to being farther from the
first axis) move longer distances through the plasma. As a result, the
plasma processing time becomes more uniform for different points on the
article surface. In some embodiments, two shuttles are provided for
loading and unloading the plasma processing system. One of the shuttles
stands empty waiting to unload the processed articles from the system,
while the other shuttle holds unprocessed articles waiting to load them
into the system. After the plasma processing terminates, the empty
shuttle unloads processed articles from the system, takes the articles
away, and gets unloaded and reloaded with unprocessed articles.
Meanwhile, the other shuttle loads unprocessed articles into the system
and the plasma processing begins. Since the plasma processing system does
not wait for the first shuttle, the productivity of the system is
increased.