Patent ID: 11259397

Abstract:
In a microwave plasma source, a tubular magnet portion has a first opening end and a second opening end. The first opening end has a first polarity, and the second opening end has a second polarity. The tubular body is surrounded by the tubular magnet portion. A first magnetic circuit portion closes the first opening end. A second magnetic circuit portion is disposed opposite to the first magnetic circuit portion. The second magnetic circuit portion has a first opening part. An antenna penetrates the first magnetic circuit portion, is introduced to a space, and supplies microwave power to the space. The nozzle portion has a second opening part that has a smaller opening area than the first opening part and communicates with the first opening part. When an inner diameter of the tubular body is represented by a (mm), and a microwave cutoff wavelength of the microwave power being supplied to the space is represented by λ (mm), the microwave plasma source is configured to satisfy a relational expression λ>3.41×(a/2).