Patent ID: 7779783

Claim:
A plasma processing apparatus for performing a process on a substrate by exposing the substrate to a plasma, the apparatus comprising: A microwave source; A coaxial waveguide comprising an inner conductor and an outer conductor, wherein the inner conductor is connected to a slot antenna for supplying microwaves to the slot antenna; a chamber for accommodating therein the substrate on a susceptor, the chamber including side walls; a dielectric top plate member disposed on an upper portion of the chamber; the antenna having a plurality of slots for irradiating a microwave towards an inside of the chamber through the top plate member, the antenna being disposed on the top plate member and being in close contact therewith; a gas injection opening for supplying a processing gas into the chamber; and a vacuum pump for exhausting the inside of the chamber, wherein the top plate member includes: a dielectric flat plate portion formed to face the substrate, the dielectric flat plate portion extending substantially horizontally to the chamber side walls; and a dielectric sidewall portion formed to extend from a peripheral region of the fiat plate portion along the chamber side walls towards the substrate in a plasma generation region, wherein the sidewall portion extends substantially to the periphery of the susceptor, wherein sides of the fiat plate portion and the sidewall portion have a curved surface facing the plasma generation region and extending between the flat plate portion and the sidewall portion and a thickness of the sidewall portion between the chamber sidewalls and the plasma generation region is constant and is not smaller than λ/4 but not greater than λ g , and a thickness of the flat plate portion between the antenna and the plasma generation region is not smaller than λ/4 but not greater than λ g , λ g being a wavelength of the microwave, and wherein the microwave propagates from the flat plate portion to the sidewall portion and then is supplied towards a periphery portion of the substrate, thereby enhancing a uniformity of a plasma density in a radial direction of the substrate.