Abstract: This invention provides a local dry etching method comprising the step of removing an oxide film formed on the surface of a semiconductor water before unevenness on the semiconductor wafer is removed by scanning the surface of the semiconductor wafer at a controlled relative speed with a nozzle for applying a flow of activated species gas to the surface of the semiconductor wafer. The removal of this oxide film is carried out by widening an etching profile and a scan pitch and making the nozzle speed constant, and then flattening is carried out in the same local dry etching apparatus. For flattening, the nozzle speed is changed for each area according to initial unevenness.

Abstract: To remove nanotopography (unevenness of wavelength: 0.2 mm through 20 mm, wave height: 1 through several hundreds nm) which has already been produced on a surface of a semiconductor wafer which has been regarded as impossible to remove conventionally, a half value width of an etching profile of activated species gas is set to fall in a range equal to or smaller than a wavelength a of nanotopography and equal to or larger than a half thereof. Based on previously measured data of nanotopography, moving speed and locus of injected activated species gas along a surface of a semiconductor wafer are calculated and controlled.

Abstract: This invention provides a local dry etching method comprising the step of removing an oxide film formed on the surface of a semiconductor water before unevenness on the semiconductor wafer is removed by scanning the surface of the semiconductor wafer at a controlled relative speed with a nozzle for applying a flow of activated species gas to the surface of the semiconductor wafer. The removal of this oxide film is carried out by widening an etching profile and a scan pitch and making the nozzle speed constant, and then flattening is carried out in the same local dry etching apparatus. For flattening, the nozzle speed is changed for each area according to initial unevenness.

Abstract: In a local dry etching method of the invention, a surface of a representative wafer sampled from a lot is test etched, each wafer of which is sliced from the same ingot, and initial data of recesses and projections of which is previously known, recesses and projections of the representative wafer is measured after test etched, an etching profile is derived from the initial data and measured data and then respective wafer surfaces of the lot are etched in condition calculated by using at least the derived etching profile.

Abstract: In a local dry etching method of the invention, a surface of a representative wafer sampled from a lot is test etched, each wafer of which is sliced from the same ingot, and initial data of recesses and projections of which is previously known, recesses and projections of the representative wafer is measured after test etched, an etching profile is derived from the initial data and measured data and then respective wafer surfaces of the lot are etched in condition calculated by using at least the derived etching profile.

Abstract: To remove nanotopography (unevenness of wavelength: 0.2 mm through 20 mm, wave height: 1 through several hundreds nm) which has already been produced on a surface of a semiconductor wafer which has been regarded as impossible to remove conventionally, a half value width of an etching profile of activated species gas is set to fall in a range equal to or smaller than a wavelength a of nanotopography and equal to or larger than a half thereof. Based on previously measured data of nanotopography, moving speed and locus of injected activated species gas along a surface of a semiconductor wafer are calculated and controlled.

Abstract: 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.

Abstract: 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.