Electron beam displacement measuring method, electron beam displacement measuring device, and electron beam recording apparatus
It is an object of the present invention to make it possible to stably and correctly measure a changing amount of a beam position when a beam displacement is measured prior to a recording operation performed by an electron beam recording apparatus. A measuring device for measuring a displacement of an electron beam prior to a recording operation, comprises: a knife edge disposed at an irradiating position of the beam spot; detecting means (Farady cup or the like) for detecting an electron beam irradiating through the knife edge; filter means (high frequency cut filter or the like) for removing a changing frequency component of measurement subject from an output of the detecting means; and control means for controlling a reference position of the electron beam in accordance with an output from the filter means, in a manner such that the center of the beam spot will be at the front end position of the knife edge. A displacement of the beam spot is measured in accordance with an output change of the detecting means when the center of the beam spot deviates from the front end of the knife edge.
1. An electron beam recording apparatus, in which a beam spot of an electron beam is converged on a recording surface to form a recording pattern on the recording surface, said recording apparatus, comprising:
a beam deflection unit;
a beam position correcting unit; and
a measuring device for measuring a changing amount of a beam position when a beam displacement is measured prior to a recording operation performed by said recording apparatus,
said measuring device comprises:
a knife edge disposed at an irradiating position of the beam spot;
detecting means for detecting an electron beam irradiating through the knife edge;
a high frequency cut filter removing a changing frequency component of measurement subject from an output of the detecting means; and
control means for controlling a reference position of the electron beam in accordance with an output from the filter so that the center of the beam spot is at the front end position of the knife edge, in which a displacement of the beam spot is measured in accordance with an output change of the detecting means when the center of the beam spot deviates from the front end of the knife edge, the control of the reference position is performed in accordance with an output in which a changing frequency component of measurement subject has been removed from the detected current.
2. An electron beam displacement measuring device for use in an electron beam recording apparatus, in which a beam spot of an electron beam is converged on a recording surface to form a recording pattern on the recording surface, said measuring device comprising:
the measuring device measuring a changing amount of a beam position when a beam displacement is measured prior to a recording operation performed by said recording apparatus, said recording apparatus comprising a beam deflection unit and a beam position correcting unit;
a knife edge disposed at an irradiating position of the beam spot;
detecting means for detecting an electron beam irradiating through the knife edge;
a high frequency cut filter removing a changing frequency component of measurement subject from an output of the detecting means; and
control means for controlling a reference position of the electron beam in accordance with an output from the filter so that the center of the beam spot is at the front end position of the knife edge, in which a displacement of the beam spot is measured in accordance with an output change of the detecting means when the center of the beam spot deviates from the front end of the knife edge, the control of the reference position is performed in accordance with an output in which a changing frequency component of measurement subject has been removed from the detected current.
3. An electron beam displacement measuring method for use in an electron beam recording apparatus, in which a beam spot of an electron beam is converged on a recording surface to form a recording pattern on the recording surface, said method comprising:
disposing a knife edge of a measuring device at an irradiating position of the beam spot, the recording apparatus comprising the measuring device, a beam deflection unit and a beam position correcting unit;
detecting, by a detecting unit of the measuring device, an electron beam irradiating through the knife edge;
measuring, by the measuring device, a changing amount of a beam position when a beam displacement is measured prior to a recording operation performed by the recording apparatus;
removing, by a high frequency cut filter of the measuring device, a changing frequency component of measurement subject from an output of the detecting unit; and
controlling, by a control unit of the measuring device, a reference position of the electron beam in accordance with an output from the filter so that the center of the beam spot is at the front end position of the knife edge, in which a displacement of the beam spot is measured in accordance with an output change in a detected current when a center of the beam spot deviates from a front end of the knife edge, the controlling of the reference position is performed in accordance with an output in which a changing frequency component of measurement subject has been removed from the detected current.