There is provided a method of performing a surface treatment, such as coating,
denaturation, modification and etching, on a surface of a substrate. The method
comprises the steps of bringing a surface treatment gas into contact with a surface
of a substrate, and irradiating the surface of the substrate with a fast particle
beam to enhance an activity of the surface and/or the surface treatment gas, thereby
facilitating a reaction between the surface and the gas. The fast particle beam
may be selected from a group consisting of an electron beam, a charged particle
beam, an atomic beam and molecular beam. For example, during a coating operation,
chemical deposition of predetermined component elements of the gas onto the surface
is effected and a predetermined portion of the surface of the substrate is irradiated
with a particle beam to form a coating layer on the predetermined portion.
