Plasma generating device and plasma processing apparatus comprising such a device

A plasma generating device comprising:

• a wave guide for propagation of a microwave from a microwave oscillating source;
• a radiative part, defined by having a width, a height and a longitudinal dimension, substantially perpendicular to the width and height, along which microwaves are propagated, the radiative part being connected to said wave guide for receiving microwaves therefrom and having a plurality of slot antennas disposed along the longitudinal dimension, each of said slot antennas being adapted to radiate electromagnetic radiation corresponding to the microwave existing at respective locations of slot antennas;
• and
• a plasma generation chamber being connected to said radiative part via a window made of a dielectric material and being adapted to receive the electromagnetic radiation from said slot antennas;
• wherein at least one of the width and height of the radiative part is adapted to be locally changeable by a movable member, so that the actual wavelength of the microwave within said radiative part is allowed to be locally changed, thereby the amplitude distribution of the electromagnetic radiation being radiated from said slot antennas towards said plasma generation chamber can be controlled.