Method and apparatus for plasma forming inner magnetic bucket to control a volume of a plasma

A plasma processing apparatus for processing a substrate, comprising:

• a process chamber, comprising:
• a wall defining part of the process chamber and a plasma region;
• a gas source for providing a gas within the process chamber defined by the wall;
• a device for igniting and sustaining within the process chamber a plasma from the gas provided by the gas source for said processing;
• and
• a plasma confinement arrangement, comprising a magnetic array having a plurality of magnetic elements that are disposed within said process chamber, said plurality of magnetic elements being configured to produce a magnetic field, and wherein said plurality of magnetic elements are disposed around and the wall extend along said plasma region, and wherein said magnetic elements are within said plasma region, wherein the wall surrounds the magnetic elements and the plasma region so that plasma is able to form plasma deposition on the wall, and wherein the magnetic field produced by the magnetic elements reduces plasma deposition on the wall, wherein each of said plurality of magnetic elements extend substantially from a first end of said process chamber to a chuck, wherein the magnetic elements are spaced apart from the wall, so that the gas provided by the gas source is able to surround the magnetic elements and go into spaces between the wall and the magnetic elements, wherein said magnetic field has an azimuthally symmetric radial gradient.