A plasma source may include a plasma chamber, where the plasma chamber has a first side, defining a first plane and an extraction assembly, disposed adjacent to the side of the plasma chamber, where the extraction assembly includes at least two electrodes. A first electrode may be disposed immediately adjacent the side of the plasma chamber, wherein a second electrode defines a vertical displacement from the first electrode along a first direction, perpendicular to the first plane, wherein the first electrode comprises a first aperture, and the second electrode comprises a second aperture. The first aperture may define a lateral displacement from the second aperture along a second direction, parallel to the first plane, wherein the vertical displacement and the lateral displacement define a non-zero angle of inclination with respect to a perpendicular to the first plane.