PLANAR ANTENNA MEMBER AND PLASMA PROCESSING DEVICE EQUIPPED WITH SAME

摘要

Provided is a planar antenna capable of efficiently introducing microwaves with a lower frequency than the frequency of conventional microwaves into a processing container. The planar antenna (31) has a first slot (32a) and a second slot (32b) disposed in a concentric fashion. The ratio between the distance from the center (OA) to the center (O32a) of the first slot (32a) and the radius (r) of the planar antenna (31) is set to 0.35 to 0.5; the ratio between the distance from the center (OA) to the center (O32b) of the second slot (32b) and the radius (r) is set to 0.7 to 0.85. The longitudinal direction of the first slot (32a) is oriented at an angle of 90° to 105° with respect to the line connecting the center (OA) and the center (O32a); the longitudinal direction of the second slot (32b) is oriented at an angle of 75° to 85° with respect to the line connecting the center (OA) and the center (O32b). Further, the aperture area ratio of the slots in the planar antenna (31) to an effective circular region (31A) of the planar antenna (31) is within the range of 15% to 20%.