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AssigneeSpeedfam Corporation
InventorsMichihiko Yanagisawa, Tadayoshi Okuya
Estimating the term…
A discharge tube for a local etching apparatus has a portion positioned within a waveguide which is for the generation of plasma, the said portion being tapered so as to be divergent toward an orifice side of the discharge tube. Even in the event a maximum field strength position of a standing wave in the waveguide should be deviated due to a change in microwave transmission characteristic of the material of the discharge tube or a change in the position of a plunger under the influence of heat, the maximum field strength position lies somewhere in the vicinity of a wall surface of the tapered portion, so that a supplied gas is converted to plasma stably in a short time. When the discharge tube is to be cooled, the cooling can be done effectively with a cooling gas which is cooled by adiabatic expansion while passing through the tapered portion.
A discharge tube for a local etching apparatus wherein a microwave emitted from a microwave oscillator into a waveguide is reflected by a plunger to produce a standing wave of the microwave, said discharge tube is positioned within said standing wave, allowing gas contained in said discharge tube to be converted to plasma, and then an active species contained in the plasma is jetted to a workpiece from an orifice of said discharge tube to etch the workpiece locally,
A local etching apparatus comprising:
Dependencies are inferred from the claim text.