A chamber has an upper housing and a lower housing and receives a reaction gas. A first plasma source includes electron beam sources providing electron beams into the upper housing to generate an upper plasma. A second plasma source includes holes generating a lower plasma within the holes connecting the upper housing and the lower housing. Radicals of the upper plasma, radicals of the lower plasma, and ions of the lower plasma are provided, through the holes, to the lower housing so that the lower housing has radicals and ions at a predetermined ratio of the ions to the radicals in concentration. The second plasma source divides the chamber into the upper housing and the lower housing. A wafer chuck is positioned in the lower housing to receive a wafer.