Plasma processing apparatus and method

A semiconductor processing method in a semiconductor processing apparatus,

• said apparatus comprising:
• an I/O chamber section configured to load and unload a substrate cassette, which contains a plurality of work-piece substrates, from and to an outside of said apparatus;
• a first system configured to supply a pressure adjustment gas into said I/O chamber section;
• a first vacuum-exhaust mechanism, including a first dry pump, configured to exhaust and set said I/O chamber section at a vacuum;
• a common transfer chamber connected to said I/O chamber section via a first gate valve, and configured to distribute the substrates;
• a second system configured to supply a pressure adjustment gas into said common transfer chamber;
• a second vacuum-exhaust mechanism, including a second dry pump, configured to exhaust and set said common transfer chamber at a vacuum;
• a process chamber section connected to said common transfer chamber via a second gate valve, and configured to semiconductor-process the substrates;
• a third system configured to supply a process gas into said process chamber section;
• a third vacuum-exhaust mechanism, including a third dry pump, configured to exhaust and set said process chamber section at a vacuum, said third vacuum-exhaust mechanism further including a turbo-molecular pump connected to said process chamber section;
• a transfer unit arranged in said common transfer chamber, and configured to transfer the substrates between said I/O chamber section and said process chamber section, and
• a controller configured to drive and stop said first, second, and third dry pumps independently of each other in coordination with open/closed switching of said gate valves, while keeping said turbo-molecular pump driven;
• said method comprising the steps of:
• loading a substrate into said apparatus, and transferring the substrate from said I/O chamber section into said process chamber section through said common transfer chamber, the substrate belonging to a substrate group contained in the substrate cassette which is loaded in said I/O chamber section;
• subjecting the substrate to a semiconductor process in said process chamber section;
• transferring the substrate from said process chamber section into said I/O chamber section through said common transfer chamber, and unloading the substrate out of said apparatus;
• and
• selectively stopping said first, second, and third dry pumps, under control of said controller, for any of said I/O chamber section, said common transfer chamber, and said process chamber section, which do not have to be continuously vacuum-exhausted, during a period of time from a time when the substrate is loaded into said apparatus, to a time when the substrate is unloaded from said apparatus.