An electron beam plasma reactor includes a plasma chamber having a side wall, an upper electrode, a workpiece support to hold a workpiece facing the upper electrode with the workpiece on the support having a clear view of the upper electrode, a first RF power source coupled to said upper electrode, a gas supply, a vacuum pump coupled to the chamber to evacuate the chamber, and a controller. The controller is configured to operate the first RF power source to apply an RF power to upper electrode, and to operate the gas distributor and vacuum pump, so as to create a plasma in an upper portion of the chamber that generates an electron beam from the upper electrode toward the workpiece and a lower electron-temperature plasma in a lower portion of the chamber including the workpiece.