The potential ability to reduce industrial production cost strongly stimulates the development of non-equilibrium plasma sources for plasma assisted etching,deposition,etc.Recently,a kind of coaxial-type linear plasma source,excited by 2.45 GHz microwave,has attracted much attention because it can generate high-density and uniform plasma in one direction.The basic principle of the plasma source is that while the microwave is propagating in the coaxial waveguide,the microwave produces plasma along the surface of quartz tube by surface wave electric field.