Photomask repair method and apparatus

A photomask repair method for repairing a defect of a photomask;

• comprising:
• applying an electron beam shaped trough a beamshaping aperture to a region to be etched including a defective portion of the photomask under an atmosphere of a gas capable of effectively performing a chemical etching of a film material for forming a pattern of the photomask, thereby etching the defective portion;
• scanning an electron beam converged to be fine across a predetermined area around the defective portion, thereby permitting secondary electrons to emit to produce a pattern image, obtaining an electron intensity profile in the perpendicular direction to an edge of the pattern image produced above, thereby identifying the position of the profile corresponding to an end of the defective portion;
• and
• performing repair of the photomask while performing etching and identification, repeatedly, and terminating the etching when the edge of the defective portion reaches a proper position.

A repair apparatus for repairing a defect of a photomask, comprising:

• a chamber which houses the photomask;
• a gas inlet mechanism which introduces an etching gas into the chamber;
• an electron-detecting portion which detects secondary electrons and reflection electrons emitted from a main surface of the photomask by scanning an electron beam across the surface of the photomask;
• a pattern image formation portion which forms a pattern image of the photomask based on information brought by the detected electrons;
• and
• a beam irradiation mechanism which applies an electron beam composed of shaped beams, which are formed through beam shaping apertures and projected to the main surface of the photomask, to a region to be etched including the defective region obtained from the pattern image produced above such that a side of the beam is set in parallel to the boarder line between a non-defective pattern and the defect.

A repair apparatus for repairing a defect of a photomask, comprising:

• a chamber which houses the photomask;
• a gas inlet mechanism which introduces an etching gas into the chamber;
• an electron-detecting portion which detects secondary electrons or reflection electrons emitted from a surface of the photomask by scanning an electron beam across the surface of the photomask;
• a pattern image formation portion which forms a pattern image of the photomask based on information brought by the detected electrons;
• and
• a beam irradiation mechanism which applies a shaped beam to a defective portion obtained from the pattern image thus formed,
• wherein monitoring by electron-beam scanning and etching by shaped-beam irradiation are alternately repeated, a non-defective edge position and a defective edge position are identified from the pattern image during the monitoring, and etching is terminated when a repaired edge position reaches a proper position.