the invention provides a microwave source to assist in sputtering deposition . such a microwave source comprises a microstrip antenna that is attached to an end of a dielectric layer outside a sputtering target or cathode . the microstrip antenna comprising a dielectric coated metal strip radiates microwave between the sputtering cathode and a cathode dark space that is formed near the sputtering cathode . the microwave enhances plasma density in the cathode dark space . with the assistance of the microwave source , the sputtering target is able to operate at a lower pressure , a lower voltage and may yield higher deposition rates than without the microwave source . the target may have a generally circular or rectangular cross section . the microstrip may be of a curved strip such as a ring shape or a straight strip , depending upon the shape of the sputtering target .