NON-AMBIPOLAR ELECTRIC PRESSURE PLASMA UNIFORMITY CONTROL

摘要

This disclosure relates to a plasma processing system for controlling plasma density near the edge or perimeter of a substrate that is being processed. The plasma processing system may include a plasma chamber that can receive and process the substrate using plasma for etching the substrate, doping the substrate, or depositing a film on the substrate. This disclosure relates to a plasma processing system that may be configured to enable non-ambipolar diffusion to counter ion loss to the chamber wall. The plasma processing system may include a ring cavity coupled to the plasma processing system that is in fluid communication with plasma generated in the plasma processing system. The ring cavity may be coupled to a power source to form plasma that may diffuse ions into the plasma processing system to minimize the impact of ion loss to the chamber wall.

主权项

1. A method for treating a substrate, comprising:
providing a plasma processing chamber comprising:
a substrate holder, disposed in the processing chamber, that receives a substrate to be treated;a gas supply system for supplying a gas mixture to the processing chamber;a plasma source in the plasma processing chamber configured to energize the gas mixture into a first plasma in a first plasma region in the plasma processing chamber;a ring-shaped cavity disposed in the side wall of the plasma processing chamber, above the substrate holder, the ring-shaped cavity being in fluid communication with the plasma processing chamber via a plurality of openings disposed in the sidewall, the ring-shaped cavity comprising an electrode, wherein the ring-shaped cavity is configured to form a second plasma in a second plasma region within the ring-shaped cavity; anda DC power supply; forming the first plasma in the first plasma region; forming the second plasma in the second plasma region; and applying a positive DC bias to the electrode with the DC power supply to provide a potential difference between the first plasma region and the second plasma region and driving a non-ambipolar diffusion across the plurality of openings such that electrons diffuse from the plasma processing chamber to the cavity and ions diffuse from the cavity to the plasma processing chamber.