Coating, modification and etching of substrate surface with particle beam irradiation of the same

A method of etching a surface of a substrate, comprising the steps of:

• bringing a gas which is well reactive with the substrate into contact with a surface of a substrate to compound a gas including a component element of the substrate by a chemical reaction between the material of the substrate and the gas thereby removing the material of the substrate from the surface of the substrate, and;
• irradiating the surface of the substrate with an ultraviolet light beam or a laser beam to enhance an activity of the surface and/or the gas thereby increasing a rate of the removal of the material of the substrate in a direction along which the collimated beam is directed towards the surface of the substrate.

An apparatus for generating a fast particle beam comprising:

• a housing for receiving a predetermined gas,
• anode and cathode plates provided in said housing with a predetermined spacing being interposed therebetween and arranged in parallel with each other, anode and cathode plates each being provided with a plurality of through holes, said spacing being set to be in the range of D/14-D, in which D is a diameter of the anode and cathode plates,
• the anode and cathode plates being adapted to be applied with a high voltage to cause a plasma discharge therebetween to ionize the gas thereby forming a fast particle beam.