Controlling Radical Lifetimes in a Remote Plasma Chamber

Abstract

Remote-plasma treatments of surfaces, for example in semiconductor manufacture, can be improved by preferentially exposing the surface to only a selected subset of the plasma species generated by the plasma source. The probability that a selected species reaches the surface, or that an unselected species is quenched or otherwise converted or diverted before reaching the surface, can be manipulated by introducing additional gases with selected properties either at the plasma source or in the process chamber, varying chamber pressure or flow rate to increase or decrease collisions, or changing the dimensions or geometry of the injection ports, conduits and other passages traversed by the species. Some example processes treat surfaces preferentially with relatively low-energy radicals, vary the concentration of radicals at the surface in real time, or clean and passivate in the same unit process.

Dependencies are inferred from the claim text.