Controlled zone microwave plasma system

A microwave plasma system, comprising:

• an applicator providing microwaves having at least one wavelength;
• a process gas in the microwaves;
• at least one electrically conductive plate located in the microwaves, with each conductive plate having a plurality of tapered electrically conductive fingers that are electrically interconnected, each conductive finger having a tip that is adjacent to and disconnected from tips of adjacent conductive fingers, wherein arcing occurs between adjacent disconnected tips in the presence of the process gas and the microwaves, and wherein a process gas plasma is initiated;
• and wherein the plurality of tapered conductive fingers are formed as tapered projections, each projection having two sides forming a base and narrowing to form at least portions of the tip, wherein the bases are arranged in an array having a centroid and the tips converge toward the centroid to form an aperture that opens to an array of tapered spacings extending between the sides of the adjacent conductive fingers, the spacings widening from the tips of adjacent conductive fingers to the bases of the adjacent conductive fingers.