A plasma processing system and method wherein a power source produces a magnetic field and an electric field, and a window disposed between the power source and an interior of a plasma chamber couples the magnetic field into the plasma chamber thereby to couple power inductively into the chamber and based thereon produce a plasma in the plasma chamber. The window can be shaped and dimensioned to control an amount of power capacitively coupled to the plasma chamber by means of the electric field so that the amount of capacitively coupled power is selected in a range from zero to a predetermined amount. Also, a tuned antenna strap having r.f. power applied thereto to produce a standing wave therein can be arranged adjacent the window to couple magnetic field from a current maximum formed in the strap to the interior of the chamber. A desired amount of magnetic field and/or electric field coupling can be produced by arrangement of the chamber window adjacent that portion of the antenna strap exhibiting the desired current/voltage relationship. The system may be formed in a line source configuration, or in a cylindrical source configuration. The window may have slots and/or apertures, the size and shape of which may be variable.