Plasma Processing Systems and Methods for Chemical Processing a Substrate

A plasma processing system comprising:

• a monolithic structure comprising a plenum comprising a bottom wall, a sidewall around an edge of the bottom wall, a rim extending outwards beyond the sidewall, and a radical ballast region between the sidewall and the bottom wall, wherein the plenum is a thermally conductive structure;
• a radical source chamber comprising a gas inlet, a radio frequency (RF) electrode, and a bottom exit attached to the rim of the plenum;
• a process chamber comprising thermally conductive walls that are physically attached to the plenum at the rim, wherein the plenum comprises openings connecting which enable fluid flow between the process chamber and the radical source chamber through by way of the radical ballast region;
• and
• a substrate holder disposed below the bottom wall of the plenum.

A plasma processing method comprising:

• loading a substrate on a substrate holder disposed near a bottom of a process chamber;
• via a gas inlet, introducing process gas and carrier gas into a radical source chamber, the radical source chamber comprising an exit attached to a plenum disposed below the radical source chamber, the plenum being formed of a monolithic structure and comprising a bottom wall, a sidewall around an edge of the bottom wall, a rim extending outwards beyond the sidewall, and a radical ballast region between the sidewall and the bottom wall;
• sustaining a plasma in the radical source chamber, the plasma comprising radicals;
• transporting the radicals to the substrate in a gas flow through openings in walls of the plenum, the wall comprising the sidewall and the bottom wall;
• chemically processing a surface of the substrate with the radicals;
• and
• removing excess reactants and gaseous byproducts from the process chamber via a gas outlet disposed below the substrate holder.