Mark position measurement apparatus and mark position measurement method

A mark position measurement apparatus comprising:

• a movable stage configured to mount thereon a target object on which a plurality of marks are formed;
• a sensor configured to include an irradiator which irradiates the target object with a laser beam and a receiver which receives a reflected light from the target object irradiated with the laser beam and outputs a signal relating to a height position of an irradiated position on a surface of the target object;
• a height position calculation circuit configured to calculate a first height position by using height position information, obtained by the sensor, on each position of positions where it is assumed that the plurality of marks exist;
• a mark position calculation circuit configured to calculate, in a state where the height position of the target object has been controlled such that the first height position becomes a reference height position, positions of the plurality of marks by using change of a signal for a mark of the plurality of marks due to a state of a surface of the target object, obtained by the sensor by scanning the laser beam over the plurality of marks such that the laser beam intersects the plurality of marks;
• and
• a control circuit configured to control, in order to write a pattern on the target object with a charged particle beam, the height position of the target object such that a second height position, which is set for writing, becomes the reference height position.

A mark position measurement method comprising:

• measuring, in a state where a height position of a target object, on which a plurality of marks are formed, mounted on a stage has been controlled to be a predetermined height position, height positions of a surface of the target object by a sensor including an irradiator which irradiates the target object with a laser beam and a receiver which receives a reflected light from the target object irradiated with the laser beam and outputs a signal relating to a height position of an irradiated position on the surface of the target object;
• acquiring, a height position distribution of the surface of the target object, based on a result measured by the sensor;
• calculating, in a state where the height position of the target object has been controlled to be the predetermined height position, positions of the plurality of marks by using change of a signal for a mark of the plurality of marks due to a state of a surface of the target object, obtained by the sensor by scanning the laser beam over the plurality of marks such that the laser beam intersects the plurality of marks;
• calculating a positional deviation amount deviated from a calculated position of a mark concerned of the plurality of marks, by using an incident angle of the laser beam, and surface height positions of the target object at the positions of the plurality of marks acquired from the height position distribution of the surface of the target object;
• and
• correcting, for the plurality of marks, the calculated position of the mark concerned by using a positional deviation amount concerned in a plurality of calculated positional deviation amounts, and outputting a corrected position of the mark concerned.

A mark position measurement method comprising:

• measuring height position information on each position of positions, where it is assumed that a plurality of marks exist, on a target object which is mounted on a stage and on which the plurality of marks are formed, by a sensor including an irradiator which irradiates the target object with a laser beam and a receiver which receives a reflected light from the target object irradiated with the laser beam and outputs a signal relating to a height position of an irradiated position on a surface of the target object;
• calculating a first height position by using the height position information, obtained by the sensor, on the each position of the positions where it is assumed that the plurality of marks exist;
• calculating, in a state where a height position of the target object has been controlled such that the first height position becomes a reference height position, positions of the plurality of marks by using change of a signal for a mark of the plurality of marks due to a state of a surface of the target object, obtained by the sensor by scanning the laser beam over the plurality of marks such that the laser beam intersects the plurality of marks, and outputting calculated positions of the plurality of marks;
• and
• controlling, in order to write a pattern on the target object with a charged particle beam, the height position of the target object such that a second height position, which is set for writing, becomes the reference height position.